--- a/jdk/src/share/classes/java/lang/BootstrapMethodError.java Thu May 26 20:20:03 2011 -0700
+++ b/jdk/src/share/classes/java/lang/BootstrapMethodError.java Fri May 27 19:03:03 2011 -0700
@@ -39,14 +39,14 @@
private static final long serialVersionUID = 292L;
/**
- * Constructs an {@code BootstrapMethodError} with no detail message.
+ * Constructs a {@code BootstrapMethodError} with no detail message.
*/
public BootstrapMethodError() {
super();
}
/**
- * Constructs an {@code BootstrapMethodError} with the specified
+ * Constructs a {@code BootstrapMethodError} with the specified
* detail message.
*
* @param s the detail message.
--- a/jdk/src/share/classes/java/lang/ClassValue.java Thu May 26 20:20:03 2011 -0700
+++ b/jdk/src/share/classes/java/lang/ClassValue.java Fri May 27 19:03:03 2011 -0700
@@ -39,6 +39,13 @@
*/
public abstract class ClassValue<T> {
/**
+ * Sole constructor. (For invocation by subclass constructors, typically
+ * implicit.)
+ */
+ protected ClassValue() {
+ }
+
+ /**
* Computes the given class's derived value for this {@code ClassValue}.
* <p>
* This method will be invoked within the first thread that accesses
@@ -100,7 +107,7 @@
* If this value is subsequently {@linkplain #get read} for the same class,
* its value will be reinitialized by invoking its {@link #computeValue computeValue} method.
* This may result in an additional invocation of the
- * {@code computeValue computeValue} method for the given class.
+ * {@code computeValue} method for the given class.
* <p>
* In order to explain the interaction between {@code get} and {@code remove} calls,
* we must model the state transitions of a class value to take into account
@@ -193,6 +200,7 @@
= new WeakHashMap<Class<?>, ClassValueMap>();
private static ClassValueMap getMap(Class<?> type) {
+ type.getClass(); // test for null
return ROOT.get(type);
}
--- a/jdk/src/share/classes/java/lang/invoke/AdapterMethodHandle.java Thu May 26 20:20:03 2011 -0700
+++ b/jdk/src/share/classes/java/lang/invoke/AdapterMethodHandle.java Fri May 27 19:03:03 2011 -0700
@@ -29,6 +29,8 @@
import sun.invoke.util.Wrapper;
import sun.invoke.util.ValueConversions;
import java.util.Arrays;
+import java.util.ArrayList;
+import java.util.Collections;
import static java.lang.invoke.MethodHandleNatives.Constants.*;
import static java.lang.invoke.MethodHandleStatics.*;
@@ -62,7 +64,7 @@
// the target and change its type, instead of adding another layer.
/** Can a JVM-level adapter directly implement the proposed
- * argument conversions, as if by MethodHandles.convertArguments?
+ * argument conversions, as if by fixed-arity MethodHandle.asType?
*/
static boolean canPairwiseConvert(MethodType newType, MethodType oldType, int level) {
// same number of args, of course
@@ -92,7 +94,7 @@
}
/** Can a JVM-level adapter directly implement the proposed
- * argument conversion, as if by MethodHandles.convertArguments?
+ * argument conversion, as if by fixed-arity MethodHandle.asType?
*/
static boolean canConvertArgument(Class<?> src, Class<?> dst, int level) {
// ? Retool this logic to use RETYPE_ONLY, CHECK_CAST, etc., as opcodes,
@@ -550,6 +552,7 @@
int last = type.parameterCount() - 1;
if (type.parameterType(last) != arrayType)
target = target.asType(type.changeParameterType(last, arrayType));
+ target = target.asFixedArity(); // make sure this attribute is turned off
return new AsVarargsCollector(target, arrayType);
}
@@ -571,6 +574,11 @@
}
@Override
+ public MethodHandle asFixedArity() {
+ return target;
+ }
+
+ @Override
public MethodHandle asType(MethodType newType) {
MethodType type = this.type();
int collectArg = type.parameterCount() - 1;
@@ -594,14 +602,6 @@
cache = collector;
return collector.asType(newType);
}
-
- @Override
- public MethodHandle asVarargsCollector(Class<?> arrayType) {
- MethodType type = this.type();
- if (type.parameterType(type.parameterCount()-1) == arrayType)
- return this;
- return super.asVarargsCollector(arrayType);
- }
}
/** Can a checkcast adapter validly convert the target to newType?
@@ -747,8 +747,31 @@
if (!canUnboxArgument(newType, oldType, arg, convType, level))
return null;
MethodType castDone = newType;
- if (!VerifyType.isNullConversion(src, boxType))
+ if (!VerifyType.isNullConversion(src, boxType)) {
+ // Examples: Object->int, Number->int, Comparable->int; Byte->int, Character->int
+ if (level != 0) {
+ // must include additional conversions
+ if (src == Object.class || !Wrapper.isWrapperType(src)) {
+ // src must be examined at runtime, to detect Byte, Character, etc.
+ MethodHandle unboxMethod = (level == 1
+ ? ValueConversions.unbox(dst)
+ : ValueConversions.unboxCast(dst));
+ long conv = makeConv(OP_COLLECT_ARGS, arg, basicType(src), basicType(dst));
+ return new AdapterMethodHandle(target, newType, conv, unboxMethod);
+ }
+ // Example: Byte->int
+ // Do this by reformulating the problem to Byte->byte.
+ Class<?> srcPrim = Wrapper.forWrapperType(src).primitiveType();
+ MethodType midType = newType.changeParameterType(arg, srcPrim);
+ MethodHandle fixPrim; // makePairwiseConvert(midType, target, 0);
+ if (canPrimCast(midType, oldType, arg, dst))
+ fixPrim = makePrimCast(midType, target, arg, dst);
+ else
+ fixPrim = target;
+ return makeUnboxArgument(newType, fixPrim, arg, srcPrim, 0);
+ }
castDone = newType.changeParameterType(arg, boxType);
+ }
long conv = makeConv(OP_REF_TO_PRIM, arg, T_OBJECT, basicType(primType));
MethodHandle adapter = new AdapterMethodHandle(target, castDone, conv, boxType);
if (castDone == newType)
@@ -917,6 +940,20 @@
if (swapArg1 == swapArg2)
return target;
if (swapArg1 > swapArg2) { int t = swapArg1; swapArg1 = swapArg2; swapArg2 = t; }
+ if (type2size(newType.parameterType(swapArg1)) !=
+ type2size(newType.parameterType(swapArg2))) {
+ // turn a swap into a pair of rotates:
+ // [x a b c y] => [a b c y x] => [y a b c x]
+ int argc = swapArg2 - swapArg1 + 1;
+ final int ROT = 1;
+ ArrayList<Class<?>> rot1Params = new ArrayList<Class<?>>(target.type().parameterList());
+ Collections.rotate(rot1Params.subList(swapArg1, swapArg1 + argc), -ROT);
+ MethodType rot1Type = MethodType.methodType(target.type().returnType(), rot1Params);
+ MethodHandle rot1 = makeRotateArguments(rot1Type, target, swapArg1, argc, +ROT);
+ if (argc == 2) return rot1;
+ MethodHandle rot2 = makeRotateArguments(newType, rot1, swapArg1, argc-1, -ROT);
+ return rot2;
+ }
if (!canSwapArguments(newType, target.type(), swapArg1, swapArg2))
return null;
Class<?> swapType = newType.parameterType(swapArg1);
@@ -946,7 +983,6 @@
static boolean canRotateArguments(MethodType newType, MethodType targetType,
int firstArg, int argCount, int rotateBy) {
if (!convOpSupported(OP_ROT_ARGS)) return false;
- if (argCount <= 2) return false; // must be a swap, not a rotate
rotateBy = positiveRotation(argCount, rotateBy);
if (rotateBy == 0) return false; // no rotation
if (rotateBy > MAX_ARG_ROTATION && rotateBy < argCount - MAX_ARG_ROTATION)
@@ -992,6 +1028,7 @@
// From here on out, it assumes a single-argument shift.
assert(MAX_ARG_ROTATION == 1);
int srcArg, dstArg;
+ int dstSlot;
byte basicType;
if (chunk2Slots <= chunk1Slots) {
// Rotate right/down N (rotateBy = +N, N small, c2 small):
@@ -999,6 +1036,7 @@
// out arglist: [0: ...keep1 | arg1: c2 | arg1+N: c1... | limit: keep2... ]
srcArg = limit-1;
dstArg = firstArg;
+ dstSlot = depth0 - chunk2Slots;
basicType = basicType(newType.parameterType(srcArg));
assert(chunk2Slots == type2size(basicType));
} else {
@@ -1007,10 +1045,10 @@
// out arglist: [0: ...keep1 | arg1: c2 ... | limit-N: c1 | limit: keep2... ]
srcArg = firstArg;
dstArg = limit-1;
+ dstSlot = depth2;
basicType = basicType(newType.parameterType(srcArg));
assert(chunk1Slots == type2size(basicType));
}
- int dstSlot = newType.parameterSlotDepth(dstArg + 1);
long conv = makeSwapConv(OP_ROT_ARGS, srcArg, basicType, dstSlot);
return new AdapterMethodHandle(target, newType, conv);
}
--- a/jdk/src/share/classes/java/lang/invoke/BoundMethodHandle.java Thu May 26 20:20:03 2011 -0700
+++ b/jdk/src/share/classes/java/lang/invoke/BoundMethodHandle.java Fri May 27 19:03:03 2011 -0700
@@ -151,7 +151,7 @@
final static RuntimeException badBoundArgumentException(Object argument, MethodHandle mh, int argnum) {
String atype = (argument == null) ? "null" : argument.getClass().toString();
- return new WrongMethodTypeException("cannot bind "+atype+" argument to parameter #"+argnum+" of "+mh.type());
+ return new ClassCastException("cannot bind "+atype+" argument to parameter #"+argnum+" of "+mh.type());
}
@Override
--- a/jdk/src/share/classes/java/lang/invoke/CallSite.java Thu May 26 20:20:03 2011 -0700
+++ b/jdk/src/share/classes/java/lang/invoke/CallSite.java Fri May 27 19:03:03 2011 -0700
@@ -111,7 +111,7 @@
}
/**
- * Make a blank call site object, possibly equipped with an initial target method handle.
+ * Make a call site object equipped with an initial target method handle.
* @param target the method handle which will be the initial target of the call site
* @throws NullPointerException if the proposed target is null
*/
@@ -122,6 +122,25 @@
}
/**
+ * Make a call site object equipped with an initial target method handle.
+ * @param targetType the desired type of the call site
+ * @param createTargetHook a hook which will bind the call site to the target method handle
+ * @throws WrongMethodTypeException if the hook cannot be invoked on the required arguments,
+ * or if the target returned by the hook is not of the given {@code targetType}
+ * @throws NullPointerException if the hook returns a null value
+ * @throws ClassCastException if the hook returns something other than a {@code MethodHandle}
+ * @throws Throwable anything else thrown by the the hook function
+ */
+ /*package-private*/
+ CallSite(MethodType targetType, MethodHandle createTargetHook) throws Throwable {
+ this(targetType);
+ ConstantCallSite selfCCS = (ConstantCallSite) this;
+ MethodHandle boundTarget = (MethodHandle) createTargetHook.invokeWithArguments(selfCCS);
+ checkTargetChange(this.target, boundTarget);
+ this.target = boundTarget;
+ }
+
+ /**
* Returns the type of this call site's target.
* Although targets may change, any call site's type is permanent, and can never change to an unequal type.
* The {@code setTarget} method enforces this invariant by refusing any new target that does
@@ -129,6 +148,7 @@
* @return the type of the current target, which is also the type of any future target
*/
public MethodType type() {
+ // warning: do not call getTarget here, because CCS.getTarget can throw IllegalStateException
return target.type();
}
@@ -294,8 +314,8 @@
} else {
throw new ClassCastException("bootstrap method failed to produce a CallSite");
}
- assert(site.getTarget() != null);
- assert(site.getTarget().type().equals(type));
+ if (!site.getTarget().type().equals(type))
+ throw new WrongMethodTypeException("wrong type: "+site.getTarget());
} catch (Throwable ex) {
BootstrapMethodError bex;
if (ex instanceof BootstrapMethodError)
--- a/jdk/src/share/classes/java/lang/invoke/ConstantCallSite.java Thu May 26 20:20:03 2011 -0700
+++ b/jdk/src/share/classes/java/lang/invoke/ConstantCallSite.java Fri May 27 19:03:03 2011 -0700
@@ -32,6 +32,8 @@
* @author John Rose, JSR 292 EG
*/
public class ConstantCallSite extends CallSite {
+ private final boolean isFrozen;
+
/**
* Creates a call site with a permanent target.
* @param target the target to be permanently associated with this call site
@@ -39,6 +41,45 @@
*/
public ConstantCallSite(MethodHandle target) {
super(target);
+ isFrozen = true;
+ }
+
+ /**
+ * Creates a call site with a permanent target, possibly bound to the call site itself.
+ * <p>
+ * During construction of the call site, the {@code createTargetHook} is invoked to
+ * produce the actual target, as if by a call of the form
+ * {@code (MethodHandle) createTargetHook.invoke(this)}.
+ * <p>
+ * Note that user code cannot perform such an action directly in a subclass constructor,
+ * since the target must be fixed before the {@code ConstantCallSite} constructor returns.
+ * <p>
+ * The hook is said to bind the call site to a target method handle,
+ * and a typical action would be {@code someTarget.bindTo(this)}.
+ * However, the hook is free to take any action whatever,
+ * including ignoring the call site and returning a constant target.
+ * <p>
+ * The result returned by the hook must be a method handle of exactly
+ * the same type as the call site.
+ * <p>
+ * While the hook is being called, the new {@code ConstantCallSite}
+ * object is in a partially constructed state.
+ * In this state,
+ * a call to {@code getTarget}, or any other attempt to use the target,
+ * will result in an {@code IllegalStateException}.
+ * It is legal at all times to obtain the call site's type using the {@code type} method.
+ *
+ * @param targetType the type of the method handle to be permanently associated with this call site
+ * @param createTargetHook a method handle to invoke (on the call site) to produce the call site's target
+ * @throws WrongMethodTypeException if the hook cannot be invoked on the required arguments,
+ * or if the target returned by the hook is not of the given {@code targetType}
+ * @throws NullPointerException if the hook returns a null value
+ * @throws ClassCastException if the hook returns something other than a {@code MethodHandle}
+ * @throws Throwable anything else thrown by the the hook function
+ */
+ protected ConstantCallSite(MethodType targetType, MethodHandle createTargetHook) throws Throwable {
+ super(targetType, createTargetHook);
+ isFrozen = true;
}
/**
@@ -48,9 +89,10 @@
* to the constructor call which created this instance.
*
* @return the immutable linkage state of this call site, a constant method handle
- * @throws UnsupportedOperationException because this kind of call site cannot change its target
+ * @throws IllegalStateException if the {@code ConstantCallSite} constructor has not completed
*/
@Override public final MethodHandle getTarget() {
+ if (!isFrozen) throw new IllegalStateException();
return target;
}
@@ -61,7 +103,7 @@
* @throws UnsupportedOperationException because this kind of call site cannot change its target
*/
@Override public final void setTarget(MethodHandle ignore) {
- throw new UnsupportedOperationException("ConstantCallSite");
+ throw new UnsupportedOperationException();
}
/**
@@ -69,6 +111,7 @@
* Since that target will never change, this is a correct implementation
* of {@link CallSite#dynamicInvoker CallSite.dynamicInvoker}.
* @return the immutable linkage state of this call site, a constant method handle
+ * @throws IllegalStateException if the {@code ConstantCallSite} constructor has not completed
*/
@Override
public final MethodHandle dynamicInvoker() {
--- a/jdk/src/share/classes/java/lang/invoke/Invokers.java Thu May 26 20:20:03 2011 -0700
+++ b/jdk/src/share/classes/java/lang/invoke/Invokers.java Fri May 27 19:03:03 2011 -0700
@@ -46,7 +46,10 @@
// general invoker for the outgoing call
private /*lazy*/ MethodHandle generalInvoker;
- // general invoker for the outgoing call; accepts a single Object[]
+ // general invoker for the outgoing call, uses varargs
+ private /*lazy*/ MethodHandle varargsInvoker;
+
+ // general invoker for the outgoing call; accepts a trailing Object[]
private final /*lazy*/ MethodHandle[] spreadInvokers;
// invoker for an unbound callsite
@@ -67,45 +70,56 @@
/*non-public*/ MethodHandle exactInvoker() {
MethodHandle invoker = exactInvoker;
if (invoker != null) return invoker;
- try {
- invoker = IMPL_LOOKUP.findVirtual(MethodHandle.class, "invokeExact", targetType);
- } catch (ReflectiveOperationException ex) {
- throw new InternalError("JVM cannot find invoker for "+targetType);
- }
- assert(invokerType(targetType) == invoker.type());
+ invoker = lookupInvoker("invokeExact");
exactInvoker = invoker;
return invoker;
}
/*non-public*/ MethodHandle generalInvoker() {
- MethodHandle invoker1 = exactInvoker();
MethodHandle invoker = generalInvoker;
if (invoker != null) return invoker;
- MethodType generalType = targetType.generic();
- invoker = invoker1.asType(invokerType(generalType));
+ invoker = lookupInvoker("invoke");
generalInvoker = invoker;
return invoker;
}
+ private MethodHandle lookupInvoker(String name) {
+ MethodHandle invoker;
+ try {
+ invoker = IMPL_LOOKUP.findVirtual(MethodHandle.class, name, targetType);
+ } catch (ReflectiveOperationException ex) {
+ throw new InternalError("JVM cannot find invoker for "+targetType);
+ }
+ assert(invokerType(targetType) == invoker.type());
+ assert(!invoker.isVarargsCollector());
+ return invoker;
+ }
+
/*non-public*/ MethodHandle erasedInvoker() {
- MethodHandle invoker1 = exactInvoker();
+ MethodHandle xinvoker = exactInvoker();
MethodHandle invoker = erasedInvoker;
if (invoker != null) return invoker;
MethodType erasedType = targetType.erase();
- if (erasedType == targetType.generic())
- invoker = generalInvoker();
- else
- invoker = invoker1.asType(invokerType(erasedType));
+ invoker = xinvoker.asType(invokerType(erasedType));
erasedInvoker = invoker;
return invoker;
}
- /*non-public*/ MethodHandle spreadInvoker(int objectArgCount) {
- MethodHandle vaInvoker = spreadInvokers[objectArgCount];
+ /*non-public*/ MethodHandle spreadInvoker(int leadingArgCount) {
+ MethodHandle vaInvoker = spreadInvokers[leadingArgCount];
if (vaInvoker != null) return vaInvoker;
MethodHandle gInvoker = generalInvoker();
- vaInvoker = gInvoker.asSpreader(Object[].class, targetType.parameterCount() - objectArgCount);
- spreadInvokers[objectArgCount] = vaInvoker;
+ int spreadArgCount = targetType.parameterCount() - leadingArgCount;
+ vaInvoker = gInvoker.asSpreader(Object[].class, spreadArgCount);
+ spreadInvokers[leadingArgCount] = vaInvoker;
+ return vaInvoker;
+ }
+
+ /*non-public*/ MethodHandle varargsInvoker() {
+ MethodHandle vaInvoker = varargsInvoker;
+ if (vaInvoker != null) return vaInvoker;
+ vaInvoker = spreadInvoker(0).asType(invokerType(MethodType.genericMethodType(0, true)));
+ varargsInvoker = vaInvoker;
return vaInvoker;
}
--- a/jdk/src/share/classes/java/lang/invoke/MemberName.java Thu May 26 20:20:03 2011 -0700
+++ b/jdk/src/share/classes/java/lang/invoke/MemberName.java Fri May 27 19:03:03 2011 -0700
@@ -506,8 +506,18 @@
if (from != null) message += ", from " + from;
return new IllegalAccessException(message);
}
- public ReflectiveOperationException makeAccessException(String message) {
- message = message + ": "+ toString();
+ private String message() {
+ if (isResolved())
+ return "no access";
+ else if (isConstructor())
+ return "no such constructor";
+ else if (isMethod())
+ return "no such method";
+ else
+ return "no such field";
+ }
+ public ReflectiveOperationException makeAccessException() {
+ String message = message() + ": "+ toString();
if (isResolved())
return new IllegalAccessException(message);
else if (isConstructor())
@@ -641,7 +651,7 @@
MemberName result = resolveOrNull(m, searchSupers, lookupClass);
if (result != null)
return result;
- ReflectiveOperationException ex = m.makeAccessException("no access");
+ ReflectiveOperationException ex = m.makeAccessException();
if (ex instanceof IllegalAccessException) throw (IllegalAccessException) ex;
throw nsmClass.cast(ex);
}
--- a/jdk/src/share/classes/java/lang/invoke/MethodHandle.java Thu May 26 20:20:03 2011 -0700
+++ b/jdk/src/share/classes/java/lang/invoke/MethodHandle.java Fri May 27 19:03:03 2011 -0700
@@ -41,12 +41,12 @@
* and {@linkplain java.lang.invoke.MethodHandles#filterArguments substitution}.
*
* <h3>Method handle contents</h3>
- * Method handles are dynamically and strongly typed according to type descriptor.
- * They are not distinguished by the name or defining class of their underlying methods.
- * A method handle must be invoked using type descriptor which matches
- * the method handle's own {@linkplain #type method type}.
+ * Method handles are dynamically and strongly typed according to their parameter and return types.
+ * They are not distinguished by the name or the defining class of their underlying methods.
+ * A method handle must be invoked using a symbolic type descriptor which matches
+ * the method handle's own {@linkplain #type type descriptor}.
* <p>
- * Every method handle reports its type via the {@link #type type} accessor.
+ * Every method handle reports its type descriptor via the {@link #type type} accessor.
* This type descriptor is a {@link java.lang.invoke.MethodType MethodType} object,
* whose structure is a series of classes, one of which is
* the return type of the method (or {@code void.class} if none).
@@ -83,7 +83,7 @@
* From the viewpoint of source code, these methods can take any arguments
* and their result can be cast to any return type.
* Formally this is accomplished by giving the invoker methods
- * {@code Object} return types and variable-arity {@code Object} arguments,
+ * {@code Object} return types and variable arity {@code Object} arguments,
* but they have an additional quality called <em>signature polymorphism</em>
* which connects this freedom of invocation directly to the JVM execution stack.
* <p>
@@ -93,17 +93,17 @@
* and may not perform method invocation conversions on the arguments.
* Instead, it must push them on the stack according to their own unconverted types.
* The method handle object itself is pushed on the stack before the arguments.
- * The compiler then calls the method handle with a type descriptor which
+ * The compiler then calls the method handle with a symbolic type descriptor which
* describes the argument and return types.
* <p>
- * To issue a complete type descriptor, the compiler must also determine
+ * To issue a complete symbolic type descriptor, the compiler must also determine
* the return type. This is based on a cast on the method invocation expression,
* if there is one, or else {@code Object} if the invocation is an expression
* or else {@code void} if the invocation is a statement.
* The cast may be to a primitive type (but not {@code void}).
* <p>
* As a corner case, an uncasted {@code null} argument is given
- * a type descriptor of {@code java.lang.Void}.
+ * a symbolic type descriptor of {@code java.lang.Void}.
* The ambiguity with the type {@code Void} is harmless, since there are no references of type
* {@code Void} except the null reference.
*
@@ -112,16 +112,16 @@
* it is linked, by symbolically resolving the names in the instruction
* and verifying that the method call is statically legal.
* This is true of calls to {@code invokeExact} and {@code invoke}.
- * In this case, the type descriptor emitted by the compiler is checked for
+ * In this case, the symbolic type descriptor emitted by the compiler is checked for
* correct syntax and names it contains are resolved.
* Thus, an {@code invokevirtual} instruction which invokes
* a method handle will always link, as long
- * as the type descriptor is syntactically well-formed
+ * as the symbolic type descriptor is syntactically well-formed
* and the types exist.
* <p>
* When the {@code invokevirtual} is executed after linking,
* the receiving method handle's type is first checked by the JVM
- * to ensure that it matches the descriptor.
+ * to ensure that it matches the symbolic type descriptor.
* If the type match fails, it means that the method which the
* caller is invoking is not present on the individual
* method handle being invoked.
@@ -138,7 +138,7 @@
* (or other behavior, as the case may be).
* <p>
* A call to plain {@code invoke} works the same as a call to
- * {@code invokeExact}, if the type descriptor specified by the caller
+ * {@code invokeExact}, if the symbolic type descriptor specified by the caller
* exactly matches the method handle's own type.
* If there is a type mismatch, {@code invoke} attempts
* to adjust the type of the receiving method handle,
@@ -165,9 +165,9 @@
* method type matching takes into account both types names and class loaders.
* Thus, even if a method handle {@code M} is created in one
* class loader {@code L1} and used in another {@code L2},
- * method handle calls are type-safe, because the caller's type
+ * method handle calls are type-safe, because the caller's symbolic type
* descriptor, as resolved in {@code L2},
- * is matched against the original callee method's type descriptor,
+ * is matched against the original callee method's symbolic type descriptor,
* as resolved in {@code L1}.
* The resolution in {@code L1} happens when {@code M} is created
* and its type is assigned, while the resolution in {@code L2} happens
@@ -243,24 +243,24 @@
mh = lookup.findVirtual(String.class, "replace", mt);
s = (String) mh.invokeExact("daddy",'d','n');
// invokeExact(Ljava/lang/String;CC)Ljava/lang/String;
-assert(s.equals("nanny"));
+assertEquals(s, "nanny");
// weakly typed invocation (using MHs.invoke)
s = (String) mh.invokeWithArguments("sappy", 'p', 'v');
-assert(s.equals("savvy"));
+assertEquals(s, "savvy");
// mt is (Object[])List
mt = MethodType.methodType(java.util.List.class, Object[].class);
mh = lookup.findStatic(java.util.Arrays.class, "asList", mt);
assert(mh.isVarargsCollector());
x = mh.invoke("one", "two");
// invoke(Ljava/lang/String;Ljava/lang/String;)Ljava/lang/Object;
-assert(x.equals(java.util.Arrays.asList("one","two")));
+assertEquals(x, java.util.Arrays.asList("one","two"));
// mt is (Object,Object,Object)Object
mt = MethodType.genericMethodType(3);
mh = mh.asType(mt);
x = mh.invokeExact((Object)1, (Object)2, (Object)3);
// invokeExact(Ljava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
-assert(x.equals(java.util.Arrays.asList(1,2,3)));
-// mt is int()
+assertEquals(x, java.util.Arrays.asList(1,2,3));
+// mt is ()int
mt = MethodType.methodType(int.class);
mh = lookup.findVirtual(java.util.List.class, "size", mt);
i = (int) mh.invokeExact(java.util.Arrays.asList(1,2,3));
@@ -273,7 +273,10 @@
* </pre></blockquote>
* Each of the above calls to {@code invokeExact} or plain {@code invoke}
* generates a single invokevirtual instruction with
- * the type descriptor indicated in the following comment.
+ * the symbolic type descriptor indicated in the following comment.
+ * In these examples, the helper method {@code assertEquals} is assumed to
+ * be a method which calls {@link Objects.equals java.util.Objects#equals}
+ * on its arguments, and asserts that the result is true.
*
* <h3>Exceptions</h3>
* The methods {@code invokeExact} and {@code invoke} are declared
@@ -284,7 +287,7 @@
* there is no particular effect on bytecode shape from ascribing
* checked exceptions to method handle invocations. But in Java source
* code, methods which perform method handle calls must either explicitly
- * throw {@code java.lang.Throwable Throwable}, or else must catch all
+ * throw {@code Throwable}, or else must catch all
* throwables locally, rethrowing only those which are legal in the context,
* and wrapping ones which are illegal.
*
@@ -292,77 +295,26 @@
* The unusual compilation and linkage behavior of
* {@code invokeExact} and plain {@code invoke}
* is referenced by the term <em>signature polymorphism</em>.
- * A signature polymorphic method is one which can operate with
+ * As defined in the Java Language Specification,
+ * a signature polymorphic method is one which can operate with
* any of a wide range of call signatures and return types.
- * In order to make this work, both the Java compiler and the JVM must
- * give special treatment to signature polymorphic methods.
* <p>
* In source code, a call to a signature polymorphic method will
- * compile, regardless of the requested type descriptor.
+ * compile, regardless of the requested symbolic type descriptor.
* As usual, the Java compiler emits an {@code invokevirtual}
- * instruction with the given type descriptor against the named method.
- * The unusual part is that the type descriptor is derived from
+ * instruction with the given symbolic type descriptor against the named method.
+ * The unusual part is that the symbolic type descriptor is derived from
* the actual argument and return types, not from the method declaration.
* <p>
* When the JVM processes bytecode containing signature polymorphic calls,
- * it will successfully link any such call, regardless of its type descriptor.
+ * it will successfully link any such call, regardless of its symbolic type descriptor.
* (In order to retain type safety, the JVM will guard such calls with suitable
* dynamic type checks, as described elsewhere.)
* <p>
* Bytecode generators, including the compiler back end, are required to emit
- * untransformed type descriptors for these methods.
+ * untransformed symbolic type descriptors for these methods.
* Tools which determine symbolic linkage are required to accept such
* untransformed descriptors, without reporting linkage errors.
- * <p>
- * For the sake of tools (but not as a programming API), the signature polymorphic
- * methods are marked with a private yet standard annotation,
- * {@code @java.lang.invoke.MethodHandle.PolymorphicSignature}.
- * The annotation's retention is {@code RUNTIME}, so that all tools can see it.
- *
- * <h3>Formal rules for processing signature polymorphic methods</h3>
- * <p>
- * The following methods (and no others) are signature polymorphic:
- * <ul>
- * <li>{@link java.lang.invoke.MethodHandle#invokeExact MethodHandle.invokeExact}
- * <li>{@link java.lang.invoke.MethodHandle#invoke MethodHandle.invoke}
- * </ul>
- * <p>
- * A signature polymorphic method will be declared with the following properties:
- * <ul>
- * <li>It must be native.
- * <li>It must take a single varargs parameter of the form {@code Object...}.
- * <li>It must produce a return value of type {@code Object}.
- * <li>It must be contained within the {@code java.lang.invoke} package.
- * </ul>
- * Because of these requirements, a signature polymorphic method is able to accept
- * any number and type of actual arguments, and can, with a cast, produce a value of any type.
- * However, the JVM will treat these declaration features as a documentation convention,
- * rather than a description of the actual structure of the methods as executed.
- * <p>
- * When a call to a signature polymorphic method is compiled, the associated linkage information for
- * its arguments is not array of {@code Object} (as for other similar varargs methods)
- * but rather the erasure of the static types of all the arguments.
- * <p>
- * In an argument position of a method invocation on a signature polymorphic method,
- * a null literal has type {@code java.lang.Void}, unless cast to a reference type.
- * (<em>Note:</em> This typing rule allows the null type to have its own encoding in linkage information
- * distinct from other types.
- * <p>
- * The linkage information for the return type is derived from a context-dependent target typing convention.
- * The return type for a signature polymorphic method invocation is determined as follows:
- * <ul>
- * <li>If the method invocation expression is an expression statement, the method is {@code void}.
- * <li>Otherwise, if the method invocation expression is the immediate operand of a cast,
- * the return type is the erasure of the cast type.
- * <li>Otherwise, the return type is the method's nominal return type, {@code Object}.
- * </ul>
- * (Programmers are encouraged to use explicit casts unless it is clear that a signature polymorphic
- * call will be used as a plain {@code Object} expression.)
- * <p>
- * The linkage information for argument and return types is stored in the descriptor for the
- * compiled (bytecode) call site. As for any invocation instruction, the arguments and return value
- * will be passed directly on the JVM stack, in accordance with the descriptor,
- * and without implicit boxing or unboxing.
*
* <h3>Interoperation between method handles and the Core Reflection API</h3>
* Using factory methods in the {@link java.lang.invoke.MethodHandles.Lookup Lookup} API,
@@ -386,14 +338,14 @@
* declared method, including in this case {@code native} and {@code varargs} bits.
* <p>
* As with any reflected method, these methods (when reflected) may be
- * invoked via {@link java.lang.reflect.Method#invoke Method.invoke}.
+ * invoked via {@link java.lang.reflect.Method#invoke java.lang.reflect.Method.invoke}.
* However, such reflective calls do not result in method handle invocations.
* Such a call, if passed the required argument
* (a single one, of type {@code Object[]}), will ignore the argument and
* will throw an {@code UnsupportedOperationException}.
* <p>
* Since {@code invokevirtual} instructions can natively
- * invoke method handles under any type descriptor, this reflective view conflicts
+ * invoke method handles under any symbolic type descriptor, this reflective view conflicts
* with the normal presentation of these methods via bytecodes.
* Thus, these two native methods, when reflectively viewed by
* {@code Class.getDeclaredMethod}, may be regarded as placeholders only.
@@ -414,7 +366,7 @@
* When a method handle is invoked, the types of its arguments
* or the return value cast type may be generic types or type instances.
* If this occurs, the compiler will replace those
- * types by their erasures when when it constructs the type descriptor
+ * types by their erasures when it constructs the symbolic type descriptor
* for the {@code invokevirtual} instruction.
* <p>
* Method handles do not represent
@@ -503,17 +455,17 @@
/**
* Invokes the method handle, allowing any caller type descriptor, but requiring an exact type match.
- * The type descriptor at the call site of {@code invokeExact} must
+ * The symbolic type descriptor at the call site of {@code invokeExact} must
* exactly match this method handle's {@link #type type}.
* No conversions are allowed on arguments or return values.
* <p>
* When this method is observed via the Core Reflection API,
* it will appear as a single native method, taking an object array and returning an object.
* If this native method is invoked directly via
- * {@link java.lang.reflect.Method#invoke Method.invoke}, via JNI,
+ * {@link java.lang.reflect.Method#invoke java.lang.reflect.Method.invoke}, via JNI,
* or indirectly via {@link java.lang.invoke.MethodHandles.Lookup#unreflect Lookup.unreflect},
* it will throw an {@code UnsupportedOperationException}.
- * @throws WrongMethodTypeException if the target's type is not identical with the caller's type descriptor
+ * @throws WrongMethodTypeException if the target's type is not identical with the caller's symbolic type descriptor
* @throws Throwable anything thrown by the underlying method propagates unchanged through the method handle call
*/
public final native @PolymorphicSignature Object invokeExact(Object... args) throws Throwable;
@@ -522,7 +474,7 @@
* Invokes the method handle, allowing any caller type descriptor,
* and optionally performing conversions on arguments and return values.
* <p>
- * If the call site type descriptor exactly matches this method handle's {@link #type type},
+ * If the call site's symbolic type descriptor exactly matches this method handle's {@link #type type},
* the call proceeds as if by {@link #invokeExact invokeExact}.
* <p>
* Otherwise, the call proceeds as if this method handle were first
@@ -535,7 +487,7 @@
* adaptations directly on the caller's arguments,
* and call the target method handle according to its own exact type.
* <p>
- * The type descriptor at the call site of {@code invoke} must
+ * The resolved type descriptor at the call site of {@code invoke} must
* be a valid argument to the receivers {@code asType} method.
* In particular, the caller must specify the same argument arity
* as the callee's type,
@@ -544,24 +496,17 @@
* When this method is observed via the Core Reflection API,
* it will appear as a single native method, taking an object array and returning an object.
* If this native method is invoked directly via
- * {@link java.lang.reflect.Method#invoke Method.invoke}, via JNI,
+ * {@link java.lang.reflect.Method#invoke java.lang.reflect.Method.invoke}, via JNI,
* or indirectly via {@link java.lang.invoke.MethodHandles.Lookup#unreflect Lookup.unreflect},
* it will throw an {@code UnsupportedOperationException}.
- * @throws WrongMethodTypeException if the target's type cannot be adjusted to the caller's type descriptor
+ * @throws WrongMethodTypeException if the target's type cannot be adjusted to the caller's symbolic type descriptor
* @throws ClassCastException if the target's type can be adjusted to the caller, but a reference cast fails
* @throws Throwable anything thrown by the underlying method propagates unchanged through the method handle call
*/
public final native @PolymorphicSignature Object invoke(Object... args) throws Throwable;
/**
- * <em>Temporary alias</em> for {@link #invoke}, for backward compatibility with some versions of JSR 292.
- * On some JVMs, support can be excluded by the flags {@code -XX:+UnlockExperimentalVMOptions -XX:-AllowInvokeGeneric}.
- * @deprecated Will be removed for JSR 292 Proposed Final Draft.
- */
- public final native @PolymorphicSignature Object invokeGeneric(Object... args) throws Throwable;
-
- /**
- * Performs a varargs invocation, passing the arguments in the given array
+ * Performs a variable arity invocation, passing the arguments in the given array
* to the method handle, as if via an inexact {@link #invoke invoke} from a call site
* which mentions only the type {@code Object}, and whose arity is the length
* of the argument array.
@@ -613,56 +558,16 @@
public Object invokeWithArguments(Object... arguments) throws Throwable {
int argc = arguments == null ? 0 : arguments.length;
MethodType type = type();
- if (type.parameterCount() != argc) {
+ if (type.parameterCount() != argc || isVarargsCollector()) {
// simulate invoke
return asType(MethodType.genericMethodType(argc)).invokeWithArguments(arguments);
}
- if (argc <= 10) {
- MethodHandle invoker = type.invokers().generalInvoker();
- switch (argc) {
- case 0: return invoker.invokeExact(this);
- case 1: return invoker.invokeExact(this,
- arguments[0]);
- case 2: return invoker.invokeExact(this,
- arguments[0], arguments[1]);
- case 3: return invoker.invokeExact(this,
- arguments[0], arguments[1], arguments[2]);
- case 4: return invoker.invokeExact(this,
- arguments[0], arguments[1], arguments[2],
- arguments[3]);
- case 5: return invoker.invokeExact(this,
- arguments[0], arguments[1], arguments[2],
- arguments[3], arguments[4]);
- case 6: return invoker.invokeExact(this,
- arguments[0], arguments[1], arguments[2],
- arguments[3], arguments[4], arguments[5]);
- case 7: return invoker.invokeExact(this,
- arguments[0], arguments[1], arguments[2],
- arguments[3], arguments[4], arguments[5],
- arguments[6]);
- case 8: return invoker.invokeExact(this,
- arguments[0], arguments[1], arguments[2],
- arguments[3], arguments[4], arguments[5],
- arguments[6], arguments[7]);
- case 9: return invoker.invokeExact(this,
- arguments[0], arguments[1], arguments[2],
- arguments[3], arguments[4], arguments[5],
- arguments[6], arguments[7], arguments[8]);
- case 10: return invoker.invokeExact(this,
- arguments[0], arguments[1], arguments[2],
- arguments[3], arguments[4], arguments[5],
- arguments[6], arguments[7], arguments[8],
- arguments[9]);
- }
- }
-
- // more than ten arguments get boxed in a varargs list:
- MethodHandle invoker = type.invokers().spreadInvoker(0);
+ MethodHandle invoker = type.invokers().varargsInvoker();
return invoker.invokeExact(this, arguments);
}
/**
- * Performs a varargs invocation, passing the arguments in the given array
+ * Performs a variable arity invocation, passing the arguments in the given array
* to the method handle, as if via an inexact {@link #invoke invoke} from a call site
* which mentions only the type {@code Object}, and whose arity is the length
* of the argument array.
@@ -674,6 +579,7 @@
*
* @param arguments the arguments to pass to the target
* @return the result returned by the target
+ * @throws NullPointerException if {@code arguments} is a null reference
* @throws ClassCastException if an argument cannot be converted by reference casting
* @throws WrongMethodTypeException if the target's type cannot be adjusted to take the given number of {@code Object} arguments
* @throws Throwable anything thrown by the target method invocation
@@ -690,22 +596,95 @@
* <p>
* If the original type and new type are equal, returns {@code this}.
* <p>
+ * The new method handle, when invoked, will perform the following
+ * steps:
+ * <ul>
+ * <li>Convert the incoming argument list to match the original
+ * method handle's argument list.
+ * <li>Invoke the original method handle on the converted argument list.
+ * <li>Convert any result returned by the original method handle
+ * to the return type of new method handle.
+ * </ul>
+ * <p>
* This method provides the crucial behavioral difference between
- * {@link #invokeExact invokeExact} and plain, inexact {@link #invoke invoke}. The two methods
- * perform the same steps when the caller's type descriptor is identical
- * with the callee's, but when the types differ, plain {@link #invoke invoke}
+ * {@link #invokeExact invokeExact} and plain, inexact {@link #invoke invoke}.
+ * The two methods
+ * perform the same steps when the caller's type descriptor exactly m atches
+ * the callee's, but when the types differ, plain {@link #invoke invoke}
* also calls {@code asType} (or some internal equivalent) in order
* to match up the caller's and callee's types.
* <p>
- * This method is equivalent to {@link MethodHandles#convertArguments convertArguments},
- * except for variable arity method handles produced by {@link #asVarargsCollector asVarargsCollector}.
+ * If the current method is a variable arity method handle
+ * argument list conversion may involve the conversion and collection
+ * of several arguments into an array, as
+ * {@linkplain #asVarargsCollector described elsewhere}.
+ * In every other case, all conversions are applied <em>pairwise</em>,
+ * which means that each argument or return value is converted to
+ * exactly one argument or return value (or no return value).
+ * The applied conversions are defined by consulting the
+ * the corresponding component types of the old and new
+ * method handle types.
+ * <p>
+ * Let <em>T0</em> and <em>T1</em> be corresponding new and old parameter types,
+ * or old and new return types. Specifically, for some valid index {@code i}, let
+ * <em>T0</em>{@code =newType.parameterType(i)} and <em>T1</em>{@code =this.type().parameterType(i)}.
+ * Or else, going the other way for return values, let
+ * <em>T0</em>{@code =this.type().returnType()} and <em>T1</em>{@code =newType.returnType()}.
+ * If the types are the same, the new method handle makes no change
+ * to the corresponding argument or return value (if any).
+ * Otherwise, one of the following conversions is applied
+ * if possible:
+ * <ul>
+ * <li>If <em>T0</em> and <em>T1</em> are references, then a cast to <em>T1</em> is applied.
+ * (The types do not need to be related in any particular way.
+ * This is because a dynamic value of null can convert to any reference type.)
+ * <li>If <em>T0</em> and <em>T1</em> are primitives, then a Java method invocation
+ * conversion (JLS 5.3) is applied, if one exists.
+ * (Specifically, <em>T0</em> must convert to <em>T1</em> by a widening primitive conversion.)
+ * <li>If <em>T0</em> is a primitive and <em>T1</em> a reference,
+ * a Java casting conversion (JLS 5.5) is applied if one exists.
+ * (Specifically, the value is boxed from <em>T0</em> to its wrapper class,
+ * which is then widened as needed to <em>T1</em>.)
+ * <li>If <em>T0</em> is a reference and <em>T1</em> a primitive, an unboxing
+ * conversion will be applied at runtime, possibly followed
+ * by a Java method invocation conversion (JLS 5.3)
+ * on the primitive value. (These are the primitive widening conversions.)
+ * <em>T0</em> must be a wrapper class or a supertype of one.
+ * (In the case where <em>T0</em> is Object, these are the conversions
+ * allowed by {@link java.lang.reflect.Method#invoke java.lang.reflect.Method.invoke}.)
+ * The unboxing conversion must have a possibility of success, which means that
+ * if <em>T0</em> is not itself a wrapper class, there must exist at least one
+ * wrapper class <em>TW</em> which is a subtype of <em>T0</em> and whose unboxed
+ * primitive value can be widened to <em>T1</em>.
+ * <li>If the return type <em>T1</em> is marked as void, any returned value is discarded
+ * <li>If the return type <em>T0</em> is void and <em>T1</em> a reference, a null value is introduced.
+ * <li>If the return type <em>T0</em> is void and <em>T1</em> a primitive,
+ * a zero value is introduced.
+ * </ul>
+ * (<em>Note:</em> Both <em>T0</em> and <em>T1</em> may be regarded as static types,
+ * because neither corresponds specifically to the <em>dynamic type</em> of any
+ * actual argument or return value.)
+ * <p>
+ * The method handle conversion cannot be made if any one of the required
+ * pairwise conversions cannot be made.
+ * <p>
+ * At runtime, the conversions applied to reference arguments
+ * or return values may require additional runtime checks which can fail.
+ * An unboxing operation may fail because the original reference is null,
+ * causing a {@link java.lang.NullPointerException NullPointerException}.
+ * An unboxing operation or a reference cast may also fail on a reference
+ * to an object of the wrong type,
+ * causing a {@link java.lang.ClassCastException ClassCastException}.
+ * Although an unboxing operation may accept several kinds of wrappers,
+ * if none are available, a {@code ClassCastException} will be thrown.
*
* @param newType the expected type of the new method handle
* @return a method handle which delegates to {@code this} after performing
* any necessary argument conversions, and arranges for any
* necessary return value conversions
+ * @throws NullPointerException if {@code newType} is a null reference
* @throws WrongMethodTypeException if the conversion cannot be made
- * @see MethodHandles#convertArguments
+ * @see MethodHandles#explicitCastArguments
*/
public MethodHandle asType(MethodType newType) {
if (!type.isConvertibleTo(newType)) {
@@ -715,7 +694,7 @@
}
/**
- * Makes an adapter which accepts a trailing array argument
+ * Makes an <em>array-spreading</em> method handle, which accepts a trailing array argument
* and spreads its elements as positional arguments.
* The new method handle adapts, as its <i>target</i>,
* the current method handle. The type of the adapter will be
@@ -740,13 +719,54 @@
* contains exactly enough elements to provide a correct argument count
* to the target method handle.
* (The array may also be null when zero elements are required.)
+ * <p>
+ * Here are some simple examples of array-spreading method handles:
+ * <blockquote><pre>
+MethodHandle equals = publicLookup()
+ .findVirtual(String.class, "equals", methodType(boolean.class, Object.class));
+assert( (boolean) equals.invokeExact("me", (Object)"me"));
+assert(!(boolean) equals.invokeExact("me", (Object)"thee"));
+// spread both arguments from a 2-array:
+MethodHandle eq2 = equals.asSpreader(Object[].class, 2);
+assert( (boolean) eq2.invokeExact(new Object[]{ "me", "me" }));
+assert(!(boolean) eq2.invokeExact(new Object[]{ "me", "thee" }));
+// spread both arguments from a String array:
+MethodHandle eq2s = equals.asSpreader(String[].class, 2);
+assert( (boolean) eq2s.invokeExact(new String[]{ "me", "me" }));
+assert(!(boolean) eq2s.invokeExact(new String[]{ "me", "thee" }));
+// spread second arguments from a 1-array:
+MethodHandle eq1 = equals.asSpreader(Object[].class, 1);
+assert( (boolean) eq1.invokeExact("me", new Object[]{ "me" }));
+assert(!(boolean) eq1.invokeExact("me", new Object[]{ "thee" }));
+// spread no arguments from a 0-array or null:
+MethodHandle eq0 = equals.asSpreader(Object[].class, 0);
+assert( (boolean) eq0.invokeExact("me", (Object)"me", new Object[0]));
+assert(!(boolean) eq0.invokeExact("me", (Object)"thee", (Object[])null));
+// asSpreader and asCollector are approximate inverses:
+for (int n = 0; n <= 2; n++) {
+ for (Class<?> a : new Class<?>[]{Object[].class, String[].class, CharSequence[].class}) {
+ MethodHandle equals2 = equals.asSpreader(a, n).asCollector(a, n);
+ assert( (boolean) equals2.invokeWithArguments("me", "me"));
+ assert(!(boolean) equals2.invokeWithArguments("me", "thee"));
+ }
+}
+MethodHandle caToString = publicLookup()
+ .findStatic(Arrays.class, "toString", methodType(String.class, char[].class));
+assertEquals("[A, B, C]", (String) caToString.invokeExact("ABC".toCharArray()));
+MethodHandle caString3 = caToString.asCollector(char[].class, 3);
+assertEquals("[A, B, C]", (String) caString3.invokeExact('A', 'B', 'C'));
+MethodHandle caToString2 = caString3.asSpreader(char[].class, 2);
+assertEquals("[A, B, C]", (String) caToString2.invokeExact('A', "BC".toCharArray()));
+ * </pre></blockquote>
* @param arrayType usually {@code Object[]}, the type of the array argument from which to extract the spread arguments
* @param arrayLength the number of arguments to spread from an incoming array argument
* @return a new method handle which spreads its final array argument,
* before calling the original method handle
+ * @throws NullPointerException if {@code arrayType} is a null reference
* @throws IllegalArgumentException if {@code arrayType} is not an array type
* @throws IllegalArgumentException if target does not have at least
- * {@code arrayLength} parameter types
+ * {@code arrayLength} parameter types,
+ * or if {@code arrayLength} is negative
* @throws WrongMethodTypeException if the implied {@code asType} call fails
* @see #asCollector
*/
@@ -758,7 +778,8 @@
private void asSpreaderChecks(Class<?> arrayType, int arrayLength) {
spreadArrayChecks(arrayType, arrayLength);
int nargs = type().parameterCount();
- if (nargs < arrayLength) throw newIllegalArgumentException("bad spread array length");
+ if (nargs < arrayLength || arrayLength < 0)
+ throw newIllegalArgumentException("bad spread array length");
if (arrayType != Object[].class && arrayLength != 0) {
boolean sawProblem = false;
Class<?> arrayElement = arrayType.getComponentType();
@@ -794,7 +815,7 @@
}
/**
- * Makes an adapter which accepts a given number of trailing
+ * Makes an <em>array-collecting</em> method handle, which accepts a given number of trailing
* positional arguments and collects them into an array argument.
* The new method handle adapts, as its <i>target</i>,
* the current method handle. The type of the adapter will be
@@ -821,10 +842,40 @@
* <p>
* In order to create a collecting adapter which is not restricted to a particular
* number of collected arguments, use {@link #asVarargsCollector asVarargsCollector} instead.
+ * <p>
+ * Here are some examples of array-collecting method handles:
+ * <blockquote><pre>
+MethodHandle deepToString = publicLookup()
+ .findStatic(Arrays.class, "deepToString", methodType(String.class, Object[].class));
+assertEquals("[won]", (String) deepToString.invokeExact(new Object[]{"won"}));
+MethodHandle ts1 = deepToString.asCollector(Object[].class, 1);
+assertEquals(methodType(String.class, Object.class), ts1.type());
+//assertEquals("[won]", (String) ts1.invokeExact( new Object[]{"won"})); //FAIL
+assertEquals("[[won]]", (String) ts1.invokeExact((Object) new Object[]{"won"}));
+// arrayType can be a subtype of Object[]
+MethodHandle ts2 = deepToString.asCollector(String[].class, 2);
+assertEquals(methodType(String.class, String.class, String.class), ts2.type());
+assertEquals("[two, too]", (String) ts2.invokeExact("two", "too"));
+MethodHandle ts0 = deepToString.asCollector(Object[].class, 0);
+assertEquals("[]", (String) ts0.invokeExact());
+// collectors can be nested, Lisp-style
+MethodHandle ts22 = deepToString.asCollector(Object[].class, 3).asCollector(String[].class, 2);
+assertEquals("[A, B, [C, D]]", ((String) ts22.invokeExact((Object)'A', (Object)"B", "C", "D")));
+// arrayType can be any primitive array type
+MethodHandle bytesToString = publicLookup()
+ .findStatic(Arrays.class, "toString", methodType(String.class, byte[].class))
+ .asCollector(byte[].class, 3);
+assertEquals("[1, 2, 3]", (String) bytesToString.invokeExact((byte)1, (byte)2, (byte)3));
+MethodHandle longsToString = publicLookup()
+ .findStatic(Arrays.class, "toString", methodType(String.class, long[].class))
+ .asCollector(long[].class, 1);
+assertEquals("[123]", (String) longsToString.invokeExact((long)123));
+ * </pre></blockquote>
* @param arrayType often {@code Object[]}, the type of the array argument which will collect the arguments
* @param arrayLength the number of arguments to collect into a new array argument
* @return a new method handle which collects some trailing argument
* into an array, before calling the original method handle
+ * @throws NullPointerException if {@code arrayType} is a null reference
* @throws IllegalArgumentException if {@code arrayType} is not an array type
* or {@code arrayType} is not assignable to this method handle's trailing parameter type,
* or {@code arrayLength} is not a legal array size
@@ -838,11 +889,16 @@
return MethodHandleImpl.collectArguments(this, type.parameterCount()-1, collector);
}
- private void asCollectorChecks(Class<?> arrayType, int arrayLength) {
+ // private API: return true if last param exactly matches arrayType
+ private boolean asCollectorChecks(Class<?> arrayType, int arrayLength) {
spreadArrayChecks(arrayType, arrayLength);
int nargs = type().parameterCount();
- if (nargs == 0 || !type().parameterType(nargs-1).isAssignableFrom(arrayType))
- throw newIllegalArgumentException("array type not assignable to trailing argument", this, arrayType);
+ if (nargs != 0) {
+ Class<?> lastParam = type().parameterType(nargs-1);
+ if (lastParam == arrayType) return true;
+ if (lastParam.isAssignableFrom(arrayType)) return false;
+ }
+ throw newIllegalArgumentException("array type not assignable to trailing argument", this, arrayType);
}
/**
@@ -859,6 +915,10 @@
* {@code arrayType}, even if the target has a different
* last parameter type.
* <p>
+ * This transformation may return {@code this} if the method handle is
+ * already of variable arity and its trailing parameter type
+ * is identical to {@code arrayType}.
+ * <p>
* When called with {@link #invokeExact invokeExact}, the adapter invokes
* the target with no argument changes.
* (<em>Note:</em> This behavior is different from a
@@ -875,8 +935,8 @@
* trailing parameter type of the caller is a reference type identical to
* or assignable to the trailing parameter type of the adapter,
* the arguments and return values are converted pairwise,
- * as if by {@link MethodHandles#convertArguments convertArguments}.
- * (This is also normal behavior for {@code invoke} in such a case.)
+ * as if by {@link #asType asType} on a fixed arity
+ * method handle.
* <p>
* Otherwise, the arities differ, or the adapter's trailing parameter
* type is not assignable from the corresponding caller type.
@@ -944,14 +1004,24 @@
* <p>
* Here is an example, of a list-making variable arity method handle:
* <blockquote><pre>
+MethodHandle deepToString = publicLookup()
+ .findStatic(Arrays.class, "deepToString", methodType(String.class, Object[].class));
+MethodHandle ts1 = deepToString.asVarargsCollector(Object[].class);
+assertEquals("[won]", (String) ts1.invokeExact( new Object[]{"won"}));
+assertEquals("[won]", (String) ts1.invoke( new Object[]{"won"}));
+assertEquals("[won]", (String) ts1.invoke( "won" ));
+assertEquals("[[won]]", (String) ts1.invoke((Object) new Object[]{"won"}));
+// findStatic of Arrays.asList(...) produces a variable arity method handle:
MethodHandle asList = publicLookup()
- .findStatic(Arrays.class, "asList", methodType(List.class, Object[].class))
- .asVarargsCollector(Object[].class);
+ .findStatic(Arrays.class, "asList", methodType(List.class, Object[].class));
+assertEquals(methodType(List.class, Object[].class), asList.type());
+assert(asList.isVarargsCollector());
assertEquals("[]", asList.invoke().toString());
assertEquals("[1]", asList.invoke(1).toString());
assertEquals("[two, too]", asList.invoke("two", "too").toString());
-Object[] argv = { "three", "thee", "tee" };
+String[] argv = { "three", "thee", "tee" };
assertEquals("[three, thee, tee]", asList.invoke(argv).toString());
+assertEquals("[three, thee, tee]", asList.invoke((Object[])argv).toString());
List ls = (List) asList.invoke((Object)argv);
assertEquals(1, ls.size());
assertEquals("[three, thee, tee]", Arrays.toString((Object[])ls.get(0)));
@@ -968,38 +1038,24 @@
* or not a single trailing argument is interpreted as a whole
* array or a single element of an array to be collected.
* Note that the dynamic type of the trailing argument has no
- * effect on this decision, only a comparison between the static
- * type descriptor of the call site and the type of the method handle.)
- * <p style="font-size:smaller;">
- * As a result of the previously stated rules, the variable arity behavior
- * of a method handle may be suppressed, by binding it to the exact invoker
- * of its own type, as follows:
- * <blockquote><pre>
-MethodHandle vamh = publicLookup()
- .findStatic(Arrays.class, "asList", methodType(List.class, Object[].class))
- .asVarargsCollector(Object[].class);
-MethodHandle mh = MethodHandles.exactInvoker(vamh.type()).bindTo(vamh);
-assert(vamh.type().equals(mh.type()));
-assertEquals("[1, 2, 3]", vamh.invoke(1,2,3).toString());
-boolean failed = false;
-try { mh.invoke(1,2,3); }
-catch (WrongMethodTypeException ex) { failed = true; }
-assert(failed);
- * </pre></blockquote>
- * This transformation has no behavioral effect if the method handle is
- * not of variable arity.
+ * effect on this decision, only a comparison between the symbolic
+ * type descriptor of the call site and the type descriptor of the method handle.)
*
* @param arrayType often {@code Object[]}, the type of the array argument which will collect the arguments
* @return a new method handle which can collect any number of trailing arguments
* into an array, before calling the original method handle
+ * @throws NullPointerException if {@code arrayType} is a null reference
* @throws IllegalArgumentException if {@code arrayType} is not an array type
* or {@code arrayType} is not assignable to this method handle's trailing parameter type
* @see #asCollector
* @see #isVarargsCollector
+ * @see #asFixedArity
*/
public MethodHandle asVarargsCollector(Class<?> arrayType) {
Class<?> arrayElement = arrayType.getComponentType();
- asCollectorChecks(arrayType, 0);
+ boolean lastMatch = asCollectorChecks(arrayType, 0);
+ if (isVarargsCollector() && lastMatch)
+ return this;
return AdapterMethodHandle.makeVarargsCollector(this, arrayType);
}
@@ -1016,12 +1072,61 @@
* </ul>
* @return true if this method handle accepts more than one arity of plain, inexact {@code invoke} calls
* @see #asVarargsCollector
+ * @see #asFixedArity
*/
public boolean isVarargsCollector() {
return false;
}
/**
+ * Makes a <em>fixed arity</em> method handle which is otherwise
+ * equivalent to the the current method handle.
+ * <p>
+ * If the current method handle is not of
+ * {@linkplain #asVarargsCollector variable arity},
+ * the current method handle is returned.
+ * This is true even if the current method handle
+ * could not be a valid input to {@code asVarargsCollector}.
+ * <p>
+ * Otherwise, the resulting fixed-arity method handle has the same
+ * type and behavior of the current method handle,
+ * except that {@link #isVarargsCollector isVarargsCollector}
+ * will be false.
+ * The fixed-arity method handle may (or may not) be the
+ * a previous argument to {@code asVarargsCollector}.
+ * <p>
+ * Here is an example, of a list-making variable arity method handle:
+ * <blockquote><pre>
+MethodHandle asListVar = publicLookup()
+ .findStatic(Arrays.class, "asList", methodType(List.class, Object[].class))
+ .asVarargsCollector(Object[].class);
+MethodHandle asListFix = asListVar.asFixedArity();
+assertEquals("[1]", asListVar.invoke(1).toString());
+Exception caught = null;
+try { asListFix.invoke((Object)1); }
+catch (Exception ex) { caught = ex; }
+assert(caught instanceof ClassCastException);
+assertEquals("[two, too]", asListVar.invoke("two", "too").toString());
+try { asListFix.invoke("two", "too"); }
+catch (Exception ex) { caught = ex; }
+assert(caught instanceof WrongMethodTypeException);
+Object[] argv = { "three", "thee", "tee" };
+assertEquals("[three, thee, tee]", asListVar.invoke(argv).toString());
+assertEquals("[three, thee, tee]", asListFix.invoke(argv).toString());
+assertEquals(1, ((List) asListVar.invoke((Object)argv)).size());
+assertEquals("[three, thee, tee]", asListFix.invoke((Object)argv).toString());
+ * </pre></blockquote>
+ *
+ * @return a new method handle which accepts only a fixed number of arguments
+ * @see #asVarargsCollector
+ * @see #isVarargsCollector
+ */
+ public MethodHandle asFixedArity() {
+ assert(!isVarargsCollector());
+ return this;
+ }
+
+ /**
* Binds a value {@code x} to the first argument of a method handle, without invoking it.
* The new method handle adapts, as its <i>target</i>,
* the current method handle by binding it to the given argument.
--- a/jdk/src/share/classes/java/lang/invoke/MethodHandleImpl.java Thu May 26 20:20:03 2011 -0700
+++ b/jdk/src/share/classes/java/lang/invoke/MethodHandleImpl.java Fri May 27 19:03:03 2011 -0700
@@ -82,12 +82,17 @@
}
DirectMethodHandle mh = new DirectMethodHandle(mtype, method, doDispatch, lookupClass);
if (!mh.isValid())
- throw method.makeAccessException("no access", lookupClass);
+ throw method.makeAccessException("no direct method handle", lookupClass);
assert(mh.type() == mtype);
if (!method.isVarargs())
return mh;
- else
- return mh.asVarargsCollector(mtype.parameterType(mtype.parameterCount()-1));
+ int argc = mtype.parameterCount();
+ if (argc != 0) {
+ Class<?> arrayType = mtype.parameterType(argc-1);
+ if (arrayType.isArray())
+ return AdapterMethodHandle.makeVarargsCollector(mh, arrayType);
+ }
+ throw method.makeAccessException("cannot make variable arity", null);
}
static
@@ -485,14 +490,14 @@
*/
static
MethodHandle bindReceiver(MethodHandle target, Object receiver) {
+ if (receiver == null) return null;
if (target instanceof AdapterMethodHandle &&
((AdapterMethodHandle)target).conversionOp() == MethodHandleNatives.Constants.OP_RETYPE_ONLY
) {
Object info = MethodHandleNatives.getTargetInfo(target);
if (info instanceof DirectMethodHandle) {
DirectMethodHandle dmh = (DirectMethodHandle) info;
- if (receiver == null ||
- dmh.type().parameterType(0).isAssignableFrom(receiver.getClass())) {
+ if (dmh.type().parameterType(0).isAssignableFrom(receiver.getClass())) {
MethodHandle bmh = new BoundMethodHandle(dmh, receiver, 0);
MethodType newType = target.type().dropParameterTypes(0, 1);
return convertArguments(bmh, newType, bmh.type(), 0);
@@ -698,7 +703,9 @@
if (target == null) throw newIllegalArgumentException("cannot drop");
oldType = target.type();
}
- return convertArguments(target, newType, oldType, 0);
+ target = convertArguments(target, newType, oldType, 0);
+ assert(target != null);
+ return target;
}
/*non-public*/ static
@@ -907,14 +914,16 @@
this.test = test;
this.target = target;
this.fallback = fallback;
- assert(MethodHandleNatives.workaroundWithoutRicochetFrames()); // this code is deprecated
}
- // FIXME: Build the control flow out of foldArguments.
+ static boolean preferRicochetFrame(MethodType type) {
+ return (type.parameterCount() >= INVOKES.length || type.hasPrimitives());
+ }
static MethodHandle make(MethodHandle test, MethodHandle target, MethodHandle fallback) {
- assert(MethodHandleNatives.workaroundWithoutRicochetFrames()); // this code is deprecated
MethodType type = target.type();
int nargs = type.parameterCount();
if (nargs < INVOKES.length) {
+ if (preferRicochetFrame(type))
+ assert(MethodHandleNatives.workaroundWithoutRicochetFrames()); // this code is deprecated
MethodHandle invoke = INVOKES[nargs];
MethodType gtype = type.generic();
assert(invoke.type().dropParameterTypes(0,1) == gtype);
@@ -925,6 +934,7 @@
MethodHandle gguard = new GuardWithTest(invoke, gtest, gtarget, gfallback);
return convertArguments(gguard, type, gtype, 0);
} else {
+ assert(MethodHandleNatives.workaroundWithoutRicochetFrames()); // this code is deprecated
MethodHandle invoke = VARARGS_INVOKE;
MethodType gtype = MethodType.genericMethodType(1);
assert(invoke.type().dropParameterTypes(0,1) == gtype);
@@ -1048,8 +1058,10 @@
// where select(z) = select(z, t, f).bindTo(t, f) => z ? t f
// [tailcall]=> tf(arg...)
assert(test.type().returnType() == boolean.class);
- MethodType foldTargetType = target.type().insertParameterTypes(0, boolean.class);
- if (AdapterMethodHandle.canCollectArguments(foldTargetType, test.type(), 0, true)) {
+ MethodType targetType = target.type();
+ MethodType foldTargetType = targetType.insertParameterTypes(0, boolean.class);
+ if (AdapterMethodHandle.canCollectArguments(foldTargetType, test.type(), 0, true)
+ && GuardWithTest.preferRicochetFrame(targetType)) {
// working backwards, as usual:
assert(target.type().equals(fallback.type()));
MethodHandle tailcall = MethodHandles.exactInvoker(target.type());
@@ -1062,7 +1074,6 @@
MethodHandle fold = foldArguments(filter, filter.type().dropParameterTypes(0, 1), 0, test);
return fold;
}
- assert(MethodHandleNatives.workaroundWithoutRicochetFrames()); // this code is deprecated
return GuardWithTest.make(test, target, fallback);
}
--- a/jdk/src/share/classes/java/lang/invoke/MethodHandleNatives.java Thu May 26 20:20:03 2011 -0700
+++ b/jdk/src/share/classes/java/lang/invoke/MethodHandleNatives.java Fri May 27 19:03:03 2011 -0700
@@ -400,7 +400,7 @@
case REF_newInvokeSpecial: return lookup.findConstructor( defc, (MethodType) type );
case REF_invokeInterface: return lookup.findVirtual( defc, name, (MethodType) type );
}
- throw new IllegalArgumentException("bad MethodHandle constant "+name+" : "+type);
+ throw new InternalError("bad MethodHandle constant "+name+" : "+type);
} catch (ReflectiveOperationException ex) {
Error err = new IncompatibleClassChangeError();
err.initCause(ex);
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/java/lang/invoke/MethodHandleProxies.java Fri May 27 19:03:03 2011 -0700
@@ -0,0 +1,257 @@
+/*
+ * Copyright (c) 2008, 2011, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package java.lang.invoke;
+
+import java.lang.reflect.*;
+import sun.invoke.WrapperInstance;
+
+/**
+ * This class consists exclusively of static methods that help adapt
+ * method handles to other JVM types, such as interfaces.
+ */
+public class MethodHandleProxies {
+
+ private MethodHandleProxies() { } // do not instantiate
+
+ /**
+ * Produces an instance of the given single-method interface which redirects
+ * its calls to the given method handle.
+ * <p>
+ * A single-method interface is an interface which declares a uniquely named method.
+ * When determining the uniquely named method of a single-method interface,
+ * the public {@code Object} methods ({@code toString}, {@code equals}, {@code hashCode})
+ * are disregarded. For example, {@link java.util.Comparator} is a single-method interface,
+ * even though it re-declares the {@code Object.equals} method.
+ * <p>
+ * The interface must be public. No additional access checks are performed.
+ * <p>
+ * The resulting instance of the required type will respond to
+ * invocation of the type's uniquely named method by calling
+ * the given target on the incoming arguments,
+ * and returning or throwing whatever the target
+ * returns or throws. The invocation will be as if by
+ * {@code target.invoke}.
+ * The target's type will be checked before the
+ * instance is created, as if by a call to {@code asType},
+ * which may result in a {@code WrongMethodTypeException}.
+ * <p>
+ * The uniquely named method is allowed to be multiply declared,
+ * with distinct type descriptors. (E.g., it can be overloaded,
+ * or can possess bridge methods.) All such declarations are
+ * connected directly to the target method handle.
+ * Argument and return types are adjusted by {@code asType}
+ * for each individual declaration.
+ * <p>
+ * The wrapper instance will implement the requested interface
+ * and its super-types, but no other single-method interfaces.
+ * This means that the instance will not unexpectedly
+ * pass an {@code instanceof} test for any unrequested type.
+ * <p style="font-size:smaller;">
+ * <em>Implementation Note:</em>
+ * Therefore, each instance must implement a unique single-method interface.
+ * Implementations may not bundle together
+ * multiple single-method interfaces onto single implementation classes
+ * in the style of {@link java.awt.AWTEventMulticaster}.
+ * <p>
+ * The method handle may throw an <em>undeclared exception</em>,
+ * which means any checked exception (or other checked throwable)
+ * not declared by the requested type's single abstract method.
+ * If this happens, the throwable will be wrapped in an instance of
+ * {@link java.lang.reflect.UndeclaredThrowableException UndeclaredThrowableException}
+ * and thrown in that wrapped form.
+ * <p>
+ * Like {@link java.lang.Integer#valueOf Integer.valueOf},
+ * {@code asInterfaceInstance} is a factory method whose results are defined
+ * by their behavior.
+ * It is not guaranteed to return a new instance for every call.
+ * <p>
+ * Because of the possibility of {@linkplain java.lang.reflect.Method#isBridge bridge methods}
+ * and other corner cases, the interface may also have several abstract methods
+ * with the same name but having distinct descriptors (types of returns and parameters).
+ * In this case, all the methods are bound in common to the one given target.
+ * The type check and effective {@code asType} conversion is applied to each
+ * method type descriptor, and all abstract methods are bound to the target in common.
+ * Beyond this type check, no further checks are made to determine that the
+ * abstract methods are related in any way.
+ * <p>
+ * Future versions of this API may accept additional types,
+ * such as abstract classes with single abstract methods.
+ * Future versions of this API may also equip wrapper instances
+ * with one or more additional public "marker" interfaces.
+ *
+ * @param target the method handle to invoke from the wrapper
+ * @param intfc the desired type of the wrapper, a single-method interface
+ * @return a correctly-typed wrapper for the given target
+ * @throws NullPointerException if either argument is null
+ * @throws IllegalArgumentException if the {@code intfc} is not a
+ * valid argument to this method
+ * @throws WrongMethodTypeException if the target cannot
+ * be converted to the type required by the requested interface
+ */
+ // Other notes to implementors:
+ // <p>
+ // No stable mapping is promised between the single-method interface and
+ // the implementation class C. Over time, several implementation
+ // classes might be used for the same type.
+ // <p>
+ // If the implementation is able
+ // to prove that a wrapper of the required type
+ // has already been created for a given
+ // method handle, or for another method handle with the
+ // same behavior, the implementation may return that wrapper in place of
+ // a new wrapper.
+ // <p>
+ // This method is designed to apply to common use cases
+ // where a single method handle must interoperate with
+ // an interface that implements a function-like
+ // API. Additional variations, such as single-abstract-method classes with
+ // private constructors, or interfaces with multiple but related
+ // entry points, must be covered by hand-written or automatically
+ // generated adapter classes.
+ //
+ public static
+ <T> T asInterfaceInstance(final Class<T> intfc, final MethodHandle target) {
+ // POC implementation only; violates the above contract several ways
+ final Method sm = getSingleMethod(intfc);
+ if (sm == null)
+ throw new IllegalArgumentException("not a single-method interface: "+intfc.getName());
+ MethodType smMT = MethodType.methodType(sm.getReturnType(), sm.getParameterTypes());
+ MethodHandle checkTarget = target.asType(smMT); // make throw WMT
+ checkTarget = checkTarget.asType(checkTarget.type().changeReturnType(Object.class));
+ final MethodHandle vaTarget = checkTarget.asSpreader(Object[].class, smMT.parameterCount());
+ return intfc.cast(Proxy.newProxyInstance(
+ intfc.getClassLoader(),
+ new Class[]{ intfc, WrapperInstance.class },
+ new InvocationHandler() {
+ private Object getArg(String name) {
+ if ((Object)name == "getWrapperInstanceTarget") return target;
+ if ((Object)name == "getWrapperInstanceType") return intfc;
+ throw new AssertionError();
+ }
+ public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
+ if (method.getDeclaringClass() == WrapperInstance.class)
+ return getArg(method.getName());
+ if (method.equals(sm))
+ return vaTarget.invokeExact(args);
+ if (isObjectMethod(method))
+ return callObjectMethod(this, method, args);
+ throw new InternalError();
+ }
+ }));
+ }
+
+ /**
+ * Determines if the given object was produced by a call to {@link #asInterfaceInstance asInterfaceInstance}.
+ * @param x any reference
+ * @return true if the reference is not null and points to an object produced by {@code asInterfaceInstance}
+ */
+ public static
+ boolean isWrapperInstance(Object x) {
+ return x instanceof WrapperInstance;
+ }
+
+ private static WrapperInstance asWrapperInstance(Object x) {
+ try {
+ if (x != null)
+ return (WrapperInstance) x;
+ } catch (ClassCastException ex) {
+ }
+ throw new IllegalArgumentException("not a wrapper instance");
+ }
+
+ /**
+ * Produces or recovers a target method handle which is behaviorally
+ * equivalent to the unique method of this wrapper instance.
+ * The object {@code x} must have been produced by a call to {@link #asInterfaceInstance asInterfaceInstance}.
+ * This requirement may be tested via {@link #isWrapperInstance isWrapperInstance}.
+ * @param x any reference
+ * @return a method handle implementing the unique method
+ * @throws IllegalArgumentException if the reference x is not to a wrapper instance
+ */
+ public static
+ MethodHandle wrapperInstanceTarget(Object x) {
+ return asWrapperInstance(x).getWrapperInstanceTarget();
+ }
+
+ /**
+ * Recovers the unique single-method interface type for which this wrapper instance was created.
+ * The object {@code x} must have been produced by a call to {@link #asInterfaceInstance asInterfaceInstance}.
+ * This requirement may be tested via {@link #isWrapperInstance isWrapperInstance}.
+ * @param x any reference
+ * @return the single-method interface type for which the wrapper was created
+ * @throws IllegalArgumentException if the reference x is not to a wrapper instance
+ */
+ public static
+ Class<?> wrapperInstanceType(Object x) {
+ return asWrapperInstance(x).getWrapperInstanceType();
+ }
+
+ private static
+ boolean isObjectMethod(Method m) {
+ switch (m.getName()) {
+ case "toString":
+ return (m.getReturnType() == String.class
+ && m.getParameterTypes().length == 0);
+ case "hashCode":
+ return (m.getReturnType() == int.class
+ && m.getParameterTypes().length == 0);
+ case "equals":
+ return (m.getReturnType() == boolean.class
+ && m.getParameterTypes().length == 1
+ && m.getParameterTypes()[0] == Object.class);
+ }
+ return false;
+ }
+
+ private static
+ Object callObjectMethod(Object self, Method m, Object[] args) {
+ assert(isObjectMethod(m)) : m;
+ switch (m.getName()) {
+ case "toString":
+ return self.getClass().getName() + "@" + Integer.toHexString(self.hashCode());
+ case "hashCode":
+ return System.identityHashCode(self);
+ case "equals":
+ return (self == args[0]);
+ }
+ return null;
+ }
+
+ private static
+ Method getSingleMethod(Class<?> intfc) {
+ if (!intfc.isInterface()) return null;
+ Method sm = null;
+ for (Method m : intfc.getMethods()) {
+ int mod = m.getModifiers();
+ if (Modifier.isAbstract(mod)) {
+ if (sm != null && !isObjectMethod(sm))
+ return null; // too many abstract methods
+ sm = m;
+ }
+ }
+ return sm;
+ }
+}
--- a/jdk/src/share/classes/java/lang/invoke/MethodHandles.java Thu May 26 20:20:03 2011 -0700
+++ b/jdk/src/share/classes/java/lang/invoke/MethodHandles.java Fri May 27 19:03:03 2011 -0700
@@ -180,6 +180,10 @@
* The names {@code aMethod}, {@code aField}, and {@code aConstructor} stand
* for reflective objects corresponding to the given members.
* <p>
+ * In cases where the given member is of variable arity (i.e., a method or constructor)
+ * the returned method handle will also be of {@linkplain MethodHandle#asVarargsCollector variable arity}.
+ * In all other cases, the returned method handle will be of fixed arity.
+ * <p>
* The equivalence between looked-up method handles and underlying
* class members can break down in a few ways:
* <ul>
@@ -201,7 +205,7 @@
* Access checks are applied in the factory methods of {@code Lookup},
* when a method handle is created.
* This is a key difference from the Core Reflection API, since
- * {@link java.lang.reflect.Method#invoke Method.invoke}
+ * {@link java.lang.reflect.Method#invoke java.lang.reflect.Method.invoke}
* performs access checking against every caller, on every call.
* <p>
* All access checks start from a {@code Lookup} object, which
@@ -267,7 +271,7 @@
* Access checks only apply to named and reflected methods,
* constructors, and fields.
* Other method handle creation methods, such as
- * {@link #convertArguments MethodHandles.convertArguments},
+ * {@link MethodHandle#asType MethodHandle.asType},
* do not require any access checks, and are done
* with static methods of {@link MethodHandles},
* independently of any {@code Lookup} object.
@@ -296,6 +300,12 @@
* {@link SecurityManager#checkMemberAccess
* smgr.checkMemberAccess(defc, Member.DECLARED)} is called.
* (Note that {@code defc} might be the same as {@code refc}.)
+ * The default implementation of this security manager method
+ * inspects the stack to determine the original caller of
+ * the reflective request (such as {@code findStatic}),
+ * and performs additional permission checks if the
+ * class loader of {@code defc} differs from the class
+ * loader of the class from which the reflective request came.
* <li>If the retrieved member is not public,
* and if {@code defc} and {@code refc} are in different class loaders,
* and if the class loader of the lookup class is not
@@ -304,8 +314,6 @@
* smgr.checkPackageAccess(defcPkg)} is called,
* where {@code defcPkg} is the package of {@code defc}.
* </ul>
- * In all cases, the requesting class presented to the security
- * manager will be the lookup class from the current {@code Lookup} object.
*/
public static final
class Lookup {
@@ -559,7 +567,10 @@
* @param type the type of the method
* @return the desired method handle
* @throws NoSuchMethodException if the method does not exist
- * @throws IllegalAccessException if access checking fails, or if the method is not {@code static}
+ * @throws IllegalAccessException if access checking fails,
+ * or if the method is not {@code static},
+ * or if the method's variable arity modifier bit
+ * is set and {@code asVarargsCollector} fails
* @exception SecurityException if a security manager is present and it
* <a href="MethodHandles.Lookup.html#secmgr">refuses access</a>
* @throws NullPointerException if any argument is null
@@ -567,6 +578,7 @@
public
MethodHandle findStatic(Class<?> refc, String name, MethodType type) throws NoSuchMethodException, IllegalAccessException {
MemberName method = resolveOrFail(refc, name, type, true);
+ checkSecurityManager(refc, method); // stack walk magic: do not refactor
checkMethod(refc, method, true);
return MethodHandleImpl.findMethod(method, false, lookupClassOrNull());
}
@@ -601,13 +613,17 @@
* @param type the type of the method, with the receiver argument omitted
* @return the desired method handle
* @throws NoSuchMethodException if the method does not exist
- * @throws IllegalAccessException if access checking fails, or if the method is {@code static}
+ * @throws IllegalAccessException if access checking fails,
+ * or if the method is {@code static}
+ * or if the method's variable arity modifier bit
+ * is set and {@code asVarargsCollector} fails
* @exception SecurityException if a security manager is present and it
* <a href="MethodHandles.Lookup.html#secmgr">refuses access</a>
* @throws NullPointerException if any argument is null
*/
public MethodHandle findVirtual(Class<?> refc, String name, MethodType type) throws NoSuchMethodException, IllegalAccessException {
MemberName method = resolveOrFail(refc, name, type, false);
+ checkSecurityManager(refc, method); // stack walk magic: do not refactor
checkMethod(refc, method, false);
MethodHandle mh = MethodHandleImpl.findMethod(method, true, lookupClassOrNull());
return restrictProtectedReceiver(method, mh);
@@ -633,6 +649,8 @@
* @return the desired method handle
* @throws NoSuchMethodException if the constructor does not exist
* @throws IllegalAccessException if access checking fails
+ * or if the method's variable arity modifier bit
+ * is set and {@code asVarargsCollector} fails
* @exception SecurityException if a security manager is present and it
* <a href="MethodHandles.Lookup.html#secmgr">refuses access</a>
* @throws NullPointerException if any argument is null
@@ -641,6 +659,7 @@
String name = "<init>";
MemberName ctor = resolveOrFail(refc, name, type, false, false, lookupClassOrNull());
assert(ctor.isConstructor());
+ checkSecurityManager(refc, ctor); // stack walk magic: do not refactor
checkAccess(refc, ctor);
MethodHandle rawMH = MethodHandleImpl.findMethod(ctor, false, lookupClassOrNull());
MethodHandle allocMH = MethodHandleImpl.makeAllocator(rawMH);
@@ -658,7 +677,7 @@
int arity = type.parameterCount();
return mh.asVarargsCollector(type.parameterType(arity-1));
} else {
- throw new InternalError("already varargs, but template is not: "+mh);
+ return mh.asFixedArity();
}
}
@@ -690,6 +709,8 @@
* @return the desired method handle
* @throws NoSuchMethodException if the method does not exist
* @throws IllegalAccessException if access checking fails
+ * or if the method's variable arity modifier bit
+ * is set and {@code asVarargsCollector} fails
* @exception SecurityException if a security manager is present and it
* <a href="MethodHandles.Lookup.html#secmgr">refuses access</a>
* @throws NullPointerException if any argument is null
@@ -698,6 +719,7 @@
Class<?> specialCaller) throws NoSuchMethodException, IllegalAccessException {
checkSpecialCaller(specialCaller);
MemberName method = resolveOrFail(refc, name, type, false, false, specialCaller);
+ checkSecurityManager(refc, method); // stack walk magic: do not refactor
checkMethod(refc, method, false);
MethodHandle mh = MethodHandleImpl.findMethod(method, false, specialCaller);
return restrictReceiver(method, mh, specialCaller);
@@ -721,7 +743,9 @@
* @throws NullPointerException if any argument is null
*/
public MethodHandle findGetter(Class<?> refc, String name, Class<?> type) throws NoSuchFieldException, IllegalAccessException {
- return makeAccessor(refc, name, type, false, false);
+ MemberName field = resolveOrFail(refc, name, type, false);
+ checkSecurityManager(refc, field); // stack walk magic: do not refactor
+ return makeAccessor(refc, field, false, false, 0);
}
/**
@@ -742,7 +766,9 @@
* @throws NullPointerException if any argument is null
*/
public MethodHandle findSetter(Class<?> refc, String name, Class<?> type) throws NoSuchFieldException, IllegalAccessException {
- return makeAccessor(refc, name, type, false, true);
+ MemberName field = resolveOrFail(refc, name, type, false);
+ checkSecurityManager(refc, field); // stack walk magic: do not refactor
+ return makeAccessor(refc, field, false, true, 0);
}
/**
@@ -762,7 +788,9 @@
* @throws NullPointerException if any argument is null
*/
public MethodHandle findStaticGetter(Class<?> refc, String name, Class<?> type) throws NoSuchFieldException, IllegalAccessException {
- return makeAccessor(refc, name, type, true, false);
+ MemberName field = resolveOrFail(refc, name, type, true);
+ checkSecurityManager(refc, field); // stack walk magic: do not refactor
+ return makeAccessor(refc, field, false, false, 1);
}
/**
@@ -782,7 +810,9 @@
* @throws NullPointerException if any argument is null
*/
public MethodHandle findStaticSetter(Class<?> refc, String name, Class<?> type) throws NoSuchFieldException, IllegalAccessException {
- return makeAccessor(refc, name, type, true, true);
+ MemberName field = resolveOrFail(refc, name, type, true);
+ checkSecurityManager(refc, field); // stack walk magic: do not refactor
+ return makeAccessor(refc, field, false, true, 1);
}
/**
@@ -805,10 +835,13 @@
* <p>
* This is equivalent to the following code:
* <blockquote><pre>
-MethodHandle mh0 = {@link #findVirtual findVirtual}(defc, name, type);
+import static java.lang.invoke.MethodHandles.*;
+import static java.lang.invoke.MethodType.*;
+...
+MethodHandle mh0 = lookup().{@link #findVirtual findVirtual}(defc, name, type);
MethodHandle mh1 = mh0.{@link MethodHandle#bindTo bindTo}(receiver);
MethodType mt1 = mh1.type();
-if (mh0.isVarargsCollector() && mt1.parameterCount() > 0) {
+if (mh0.isVarargsCollector())
mh1 = mh1.asVarargsCollector(mt1.parameterType(mt1.parameterCount()-1));
return mh1;
* </pre></blockquote>
@@ -822,6 +855,8 @@
* @return the desired method handle
* @throws NoSuchMethodException if the method does not exist
* @throws IllegalAccessException if access checking fails
+ * or if the method's variable arity modifier bit
+ * is set and {@code asVarargsCollector} fails
* @exception SecurityException if a security manager is present and it
* <a href="MethodHandles.Lookup.html#secmgr">refuses access</a>
* @throws NullPointerException if any argument is null
@@ -829,13 +864,12 @@
public MethodHandle bind(Object receiver, String name, MethodType type) throws NoSuchMethodException, IllegalAccessException {
Class<? extends Object> refc = receiver.getClass(); // may get NPE
MemberName method = resolveOrFail(refc, name, type, false);
+ checkSecurityManager(refc, method); // stack walk magic: do not refactor
checkMethod(refc, method, false);
MethodHandle dmh = MethodHandleImpl.findMethod(method, true, lookupClassOrNull());
MethodHandle bmh = MethodHandleImpl.bindReceiver(dmh, receiver);
if (bmh == null)
throw method.makeAccessException("no access", this);
- if (dmh.type().parameterCount() == 0)
- return dmh; // bound the trailing parameter; no varargs possible
return fixVarargs(bmh, dmh);
}
@@ -856,6 +890,8 @@
* @param m the reflected method
* @return a method handle which can invoke the reflected method
* @throws IllegalAccessException if access checking fails
+ * or if the method's variable arity modifier bit
+ * is set and {@code asVarargsCollector} fails
* @throws NullPointerException if the argument is null
*/
public MethodHandle unreflect(Method m) throws IllegalAccessException {
@@ -884,6 +920,8 @@
* @param specialCaller the class nominally calling the method
* @return a method handle which can invoke the reflected method
* @throws IllegalAccessException if access checking fails
+ * or if the method's variable arity modifier bit
+ * is set and {@code asVarargsCollector} fails
* @throws NullPointerException if any argument is null
*/
public MethodHandle unreflectSpecial(Method m, Class<?> specialCaller) throws IllegalAccessException {
@@ -913,6 +951,8 @@
* @param c the reflected constructor
* @return a method handle which can invoke the reflected constructor
* @throws IllegalAccessException if access checking fails
+ * or if the method's variable arity modifier bit
+ * is set and {@code asVarargsCollector} fails
* @throws NullPointerException if the argument is null
*/
public MethodHandle unreflectConstructor(Constructor c) throws IllegalAccessException {
@@ -939,7 +979,7 @@
* @throws NullPointerException if the argument is null
*/
public MethodHandle unreflectGetter(Field f) throws IllegalAccessException {
- return makeAccessor(f.getDeclaringClass(), new MemberName(f), f.isAccessible(), false);
+ return makeAccessor(f.getDeclaringClass(), new MemberName(f), f.isAccessible(), false, -1);
}
/**
@@ -957,7 +997,7 @@
* @throws NullPointerException if the argument is null
*/
public MethodHandle unreflectSetter(Field f) throws IllegalAccessException {
- return makeAccessor(f.getDeclaringClass(), new MemberName(f), f.isAccessible(), true);
+ return makeAccessor(f.getDeclaringClass(), new MemberName(f), f.isAccessible(), true, -1);
}
/// Helper methods, all package-private.
@@ -993,6 +1033,46 @@
throw new MemberName(refc).makeAccessException("symbolic reference class is not public", this);
}
+ /**
+ * Perform necessary <a href="MethodHandles.Lookup.html#secmgr">access checks</a>.
+ * This function performs stack walk magic: do not refactor it.
+ */
+ void checkSecurityManager(Class<?> refc, MemberName m) {
+ SecurityManager smgr = System.getSecurityManager();
+ if (smgr == null) return;
+ if (allowedModes == TRUSTED) return;
+ // Step 1:
+ smgr.checkMemberAccess(refc, Member.PUBLIC);
+ // Step 2:
+ if (!VerifyAccess.classLoaderIsAncestor(lookupClass, refc))
+ smgr.checkPackageAccess(VerifyAccess.getPackageName(refc));
+ // Step 3:
+ if (m.isPublic()) return;
+ Class<?> defc = m.getDeclaringClass();
+ smgr.checkMemberAccess(defc, Member.DECLARED); // STACK WALK HERE
+ // Step 4:
+ if (defc != refc)
+ smgr.checkPackageAccess(VerifyAccess.getPackageName(defc));
+
+ // Comment from SM.checkMemberAccess, where which=DECLARED:
+ /*
+ * stack depth of 4 should be the caller of one of the
+ * methods in java.lang.Class that invoke checkMember
+ * access. The stack should look like:
+ *
+ * someCaller [3]
+ * java.lang.Class.someReflectionAPI [2]
+ * java.lang.Class.checkMemberAccess [1]
+ * SecurityManager.checkMemberAccess [0]
+ *
+ */
+ // For us it is this stack:
+ // someCaller [3]
+ // Lookup.findSomeMember [2]
+ // Lookup.checkSecurityManager [1]
+ // SecurityManager.checkMemberAccess [0]
+ }
+
void checkMethod(Class<?> refc, MemberName m, boolean wantStatic) throws IllegalAccessException {
String message;
if (m.isConstructor())
@@ -1085,19 +1165,14 @@
return fixVarargs(narrowMH, mh);
}
- MethodHandle makeAccessor(Class<?> refc, String name, Class<?> type,
- boolean isStatic, boolean isSetter) throws NoSuchFieldException, IllegalAccessException {
- MemberName field = resolveOrFail(refc, name, type, isStatic);
- if (isStatic != field.isStatic())
- throw field.makeAccessException(isStatic
+ MethodHandle makeAccessor(Class<?> refc, MemberName field,
+ boolean trusted, boolean isSetter,
+ int checkStatic) throws IllegalAccessException {
+ assert(field.isField());
+ if (checkStatic >= 0 && (checkStatic != 0) != field.isStatic())
+ throw field.makeAccessException((checkStatic != 0)
? "expected a static field"
: "expected a non-static field", this);
- return makeAccessor(refc, field, false, isSetter);
- }
-
- MethodHandle makeAccessor(Class<?> refc, MemberName field,
- boolean trusted, boolean isSetter) throws IllegalAccessException {
- assert(field.isField());
if (trusted)
return MethodHandleImpl.accessField(field, isSetter, lookupClassOrNull());
checkAccess(refc, field);
@@ -1139,50 +1214,51 @@
/**
* Produces a method handle which will invoke any method handle of the
- * given {@code type} on a standard set of {@code Object} type arguments
- * and a single trailing {@code Object[]} array.
+ * given {@code type}, with a given number of trailing arguments replaced by
+ * a single trailing {@code Object[]} array.
* The resulting invoker will be a method handle with the following
* arguments:
* <ul>
* <li>a single {@code MethodHandle} target
- * <li>zero or more {@code Object} values (counted by {@code objectArgCount})
- * <li>an {@code Object[]} array containing more arguments
+ * <li>zero or more leading values (counted by {@code leadingArgCount})
+ * <li>an {@code Object[]} array containing trailing arguments
* </ul>
* <p>
- * The invoker will behave like a call to {@link MethodHandle#invoke invoke} with
+ * The invoker will invoke its target like a call to {@link MethodHandle#invoke invoke} with
* the indicated {@code type}.
* That is, if the target is exactly of the given {@code type}, it will behave
* like {@code invokeExact}; otherwise it behave as if {@link MethodHandle#asType asType}
* is used to convert the target to the required {@code type}.
* <p>
* The type of the returned invoker will not be the given {@code type}, but rather
- * will have all parameter and return types replaced by {@code Object}, except for
- * the last parameter type, which will be the array type {@code Object[]}.
+ * will have all parameters except the first {@code leadingArgCount}
+ * replaced by a single array of type {@code Object[]}, which will be
+ * the final parameter.
* <p>
- * Before invoking its target, the invoker will spread the varargs array, apply
+ * Before invoking its target, the invoker will spread the final array, apply
* reference casts as necessary, and unbox and widen primitive arguments.
- * The return value of the invoker will be an {@code Object} reference,
- * boxing a primitive value if the original type returns a primitive,
- * and always null if the original type returns void.
* <p>
* This method is equivalent to the following code (though it may be more efficient):
* <p><blockquote><pre>
MethodHandle invoker = MethodHandles.invoker(type);
-int spreadArgCount = type.parameterCount - objectArgCount;
+int spreadArgCount = type.parameterCount() - leadingArgCount;
invoker = invoker.asSpreader(Object[].class, spreadArgCount);
return invoker;
* </pre></blockquote>
* <p>
* This method throws no reflective or security exceptions.
* @param type the desired target type
- * @param objectArgCount number of fixed (non-varargs) {@code Object} arguments
+ * @param leadingArgCount number of fixed arguments, to be passed unchanged to the target
* @return a method handle suitable for invoking any method handle of the given type
+ * @throws NullPointerException if {@code type} is null
+ * @throws IllegalArgumentException if {@code leadingArgCount} is not in
+ * the range from 0 to {@code type.parameterCount()} inclusive
*/
static public
- MethodHandle spreadInvoker(MethodType type, int objectArgCount) {
- if (objectArgCount < 0 || objectArgCount > type.parameterCount())
- throw new IllegalArgumentException("bad argument count "+objectArgCount);
- return type.invokers().spreadInvoker(objectArgCount);
+ MethodHandle spreadInvoker(MethodType type, int leadingArgCount) {
+ if (leadingArgCount < 0 || leadingArgCount > type.parameterCount())
+ throw new IllegalArgumentException("bad argument count "+leadingArgCount);
+ return type.invokers().spreadInvoker(leadingArgCount);
}
/**
@@ -1212,7 +1288,7 @@
* method handle values, as long as they are compatible with the type of {@code X}.
* <p>
* <em>(Note: The invoker method is not available via the Core Reflection API.
- * An attempt to call {@linkplain java.lang.reflect.Method#invoke Method.invoke}
+ * An attempt to call {@linkplain java.lang.reflect.Method#invoke java.lang.reflect.Method.invoke}
* on the declared {@code invokeExact} or {@code invoke} method will raise an
* {@link java.lang.UnsupportedOperationException UnsupportedOperationException}.)</em>
* <p>
@@ -1232,12 +1308,18 @@
* exactly equal to the desired type, except that it will accept
* an additional leading argument of type {@code MethodHandle}.
* <p>
- * Before invoking its target, the invoker will apply reference casts as
+ * Before invoking its target, if the target differs from the expected type,
+ * the invoker will apply reference casts as
* necessary and box, unbox, or widen primitive values, as if by {@link MethodHandle#asType asType}.
* Similarly, the return value will be converted as necessary.
* If the target is a {@linkplain MethodHandle#asVarargsCollector variable arity method handle},
* the required arity conversion will be made, again as if by {@link MethodHandle#asType asType}.
* <p>
+ * A {@linkplain MethodType#genericMethodType general method type},
+ * mentions only {@code Object} arguments and return values.
+ * An invoker for such a type is capable of calling any method handle
+ * of the same arity as the general type.
+ * <p>
* This method is equivalent to the following code (though it may be more efficient):
* <p><blockquote><pre>
publicLookup().findVirtual(MethodHandle.class, "invoke", type)
@@ -1253,18 +1335,9 @@
}
/**
- * <em>Temporary alias</em> for {@link #invoker}, for backward compatibility with some versions of JSR 292.
- * @deprecated Will be removed for JSR 292 Proposed Final Draft.
- */
- public static
- MethodHandle genericInvoker(MethodType type) {
- return invoker(type);
- }
-
- /**
* Perform value checking, exactly as if for an adapted method handle.
* It is assumed that the given value is either null, of type T0,
- * or (if T0 is primitive) of the wrapper type corresponding to T0.
+ * or (if T0 is primitive) of the wrapper class corresponding to T0.
* The following checks and conversions are made:
* <ul>
* <li>If T0 and T1 are references, then a cast to T1 is applied.
@@ -1272,11 +1345,11 @@
* <li>If T0 and T1 are primitives, then a widening or narrowing
* conversion is applied, if one exists.
* <li>If T0 is a primitive and T1 a reference, and
- * T0 has a wrapper type TW, a boxing conversion to TW is applied,
+ * T0 has a wrapper class TW, a boxing conversion to TW is applied,
* possibly followed by a reference conversion.
* T1 must be TW or a supertype.
* <li>If T0 is a reference and T1 a primitive, and
- * T1 has a wrapper type TW, an unboxing conversion is applied,
+ * T1 has a wrapper class TW, an unboxing conversion is applied,
* possibly preceded by a reference conversion.
* T0 must be TW or a supertype.
* <li>If T1 is void, the return value is discarded
@@ -1289,6 +1362,7 @@
* @return the value, converted if necessary
* @throws java.lang.ClassCastException if a cast fails
*/
+ // FIXME: This is used in just one place. Refactor away.
static
<T0, T1> T1 checkValue(Class<T0> t0, Class<T1> t1, Object value)
throws ClassCastException
@@ -1317,6 +1391,8 @@
return w1.convert(value, t1);
}
+ // FIXME: Delete this. It is used only for insertArguments & bindTo.
+ // Replace by a more standard check.
static
Object checkValue(Class<?> T1, Object value)
throws ClassCastException
@@ -1333,137 +1409,53 @@
/**
* Produces a method handle which adapts the type of the
- * given method handle to a new type by pairwise argument conversion.
- * The original type and new type must have the same number of arguments.
- * The resulting method handle is guaranteed to report a type
- * which is equal to the desired new type.
- * <p>
- * If the original type and new type are equal, returns target.
- * <p>
- * The following conversions are applied as needed both to
- * arguments and return types. Let T0 and T1 be the differing
- * new and old parameter types (or old and new return types)
- * for corresponding values passed by the new and old method types.
- * Given those types T0, T1, one of the following conversions is applied
- * if possible:
- * <ul>
- * <li>If T0 and T1 are references, then a cast to T1 is applied.
- * (The types do not need to be related in any particular way.)
- * <li>If T0 and T1 are primitives, then a Java method invocation
- * conversion (JLS 5.3) is applied, if one exists.
- * <li>If T0 is a primitive and T1 a reference, a boxing
- * conversion is applied if one exists, possibly followed by
- * a reference conversion to a superclass.
- * T1 must be a wrapper class or a supertype of one.
- * <li>If T0 is a reference and T1 a primitive, an unboxing
- * conversion will be applied at runtime, possibly followed
- * by a Java method invocation conversion (JLS 5.3)
- * on the primitive value. (These are the widening conversions.)
- * T0 must be a wrapper class or a supertype of one.
- * (In the case where T0 is Object, these are the conversions
- * allowed by java.lang.reflect.Method.invoke.)
- * <li>If the return type T1 is void, any returned value is discarded
- * <li>If the return type T0 is void and T1 a reference, a null value is introduced.
- * <li>If the return type T0 is void and T1 a primitive, a zero value is introduced.
- * </ul>
- * @param target the method handle to invoke after arguments are retyped
- * @param newType the expected type of the new method handle
- * @return a method handle which delegates to {@code target} after performing
- * any necessary argument conversions, and arranges for any
- * necessary return value conversions
- * @throws NullPointerException if either argument is null
- * @throws WrongMethodTypeException if the conversion cannot be made
- * @see MethodHandle#asType
- * @see MethodHandles#explicitCastArguments
- */
- public static
- MethodHandle convertArguments(MethodHandle target, MethodType newType) {
- if (!target.type().isConvertibleTo(newType)) {
- throw new WrongMethodTypeException("cannot convert "+target+" to "+newType);
- }
- return MethodHandleImpl.convertArguments(target, newType, 1);
- }
-
- /**
- * Produces a method handle which adapts the type of the
- * given method handle to a new type by pairwise argument conversion.
+ * given method handle to a new type by pairwise argument and return type conversion.
* The original type and new type must have the same number of arguments.
* The resulting method handle is guaranteed to report a type
* which is equal to the desired new type.
* <p>
* If the original type and new type are equal, returns target.
* <p>
- * The same conversions are allowed as for {@link #convertArguments convertArguments},
+ * The same conversions are allowed as for {@link MethodHandle#asType MethodHandle.asType},
* and some additional conversions are also applied if those conversions fail.
- * Given types T0, T1, one of the following conversions is applied
- * in addition, if the conversions specified for {@code convertArguments}
- * would be insufficient:
+ * Given types <em>T0</em>, <em>T1</em>, one of the following conversions is applied
+ * if possible, before or instead of any conversions done by {@code asType}:
* <ul>
- * <li>If T0 and T1 are references, and T1 is an interface type,
- * then the value of type T0 is passed as a T1 without a cast.
+ * <li>If <em>T0</em> and <em>T1</em> are references, and <em>T1</em> is an interface type,
+ * then the value of type <em>T0</em> is passed as a <em>T1</em> without a cast.
* (This treatment of interfaces follows the usage of the bytecode verifier.)
- * <li>If T0 and T1 are primitives and one is boolean,
- * the boolean is treated as a one-bit unsigned integer.
+ * <li>If <em>T0</em> is boolean and <em>T1</em> is another primitive,
+ * the boolean is converted to a byte value, 1 for true, 0 for false.
* (This treatment follows the usage of the bytecode verifier.)
- * A conversion from another primitive type behaves as if
- * it first converts to byte, and then masks all but the low bit.
- * <li>If a primitive value would be converted by {@code convertArguments}
- * using Java method invocation conversion (JLS 5.3),
- * Java casting conversion (JLS 5.5) may be used also.
- * This allows primitives to be narrowed as well as widened.
+ * <li>If <em>T1</em> is boolean and <em>T0</em> is another primitive,
+ * <em>T0</em> is converted to byte via Java casting conversion (JLS 5.5),
+ * and the low order bit of the result is tested, as if by {@code (x & 1) != 0}.
+ * <li>If <em>T0</em> and <em>T1</em> are primitives other than boolean,
+ * then a Java casting conversion (JLS 5.5) is applied.
+ * (Specifically, <em>T0</em> will convert to <em>T1</em> by
+ * widening and/or narrowing.)
+ * <li>If <em>T0</em> is a reference and <em>T1</em> a primitive, an unboxing
+ * conversion will be applied at runtime, possibly followed
+ * by a Java casting conversion (JLS 5.5) on the primitive value,
+ * possibly followed by a conversion from byte to boolean by testing
+ * the low-order bit.
+ * <li>If <em>T0</em> is a reference and <em>T1</em> a primitive,
+ * and if the reference is null at runtime, a zero value is introduced.
* </ul>
* @param target the method handle to invoke after arguments are retyped
* @param newType the expected type of the new method handle
- * @return a method handle which delegates to {@code target} after performing
+ * @return a method handle which delegates to the target after performing
* any necessary argument conversions, and arranges for any
* necessary return value conversions
* @throws NullPointerException if either argument is null
* @throws WrongMethodTypeException if the conversion cannot be made
* @see MethodHandle#asType
- * @see MethodHandles#convertArguments
*/
public static
MethodHandle explicitCastArguments(MethodHandle target, MethodType newType) {
return MethodHandleImpl.convertArguments(target, newType, 2);
}
- /*
- FIXME: Reconcile javadoc with 10/22/2010 EG notes on conversion:
-
- Both converters arrange for their method handles to convert arguments
- and return values. The conversion rules are the same for arguments
- and return values, and depend only on source and target types, S and
- T. The conversions allowed by castConvertArguments are a strict
- superset of those performed by convertArguments.
-
- In all cases, if S and T are references, a simple checkcast is done.
- If neither S nor T is a primitive, no attempt is made to unbox and
- box. A failed conversion throws ClassCastException.
-
- If T is void, the value is dropped.
-
- For compatibility with reflection, if S is void and T is a reference,
- a null value is produced.
-
- For compatibility with reflection, if S is a reference and T is a
- primitive, S is first unboxed and then undergoes primitive conversion.
- In the case of 'convertArguments', only assignment conversion is
- performed (no narrowing primitive conversion).
-
- If S is a primitive, S is boxed, and then the above rules are applied.
- If S and T are both primitives, the boxing will be undetectable; only
- the primitive conversions will be apparent to the user. The key point
- is that if S is a primitive type, the implementation may box it and
- treat is as Object, without loss of information, or it may use a "fast
- path" which does not use boxing.
-
- Notwithstanding the rules above, for compatibility with the verifier,
- if T is an interface, it is treated as if it were Object. [KEEP THIS?]
-
- Also, for compatibility with the verifier, a boolean may be undergo
- widening or narrowing conversion to any other primitive type. [KEEP THIS?]
- */
-
/**
* Produces a method handle which adapts the calling sequence of the
* given method handle to a new type, by reordering the arguments.
@@ -1482,8 +1474,8 @@
* <p>
* No argument or return value conversions are applied.
* The type of each incoming argument, as determined by {@code newType},
- * must be identical to the type of the corresponding outgoing argument
- * or arguments in the target method handle.
+ * must be identical to the type of the corresponding outgoing parameter
+ * or parameters in the target method handle.
* The return type of {@code newType} must be identical to the return
* type of the original target.
* <p>
@@ -1495,25 +1487,33 @@
* incoming arguments which are not mentioned in the reordering array
* are may be any type, as determined only by {@code newType}.
* <blockquote><pre>
-MethodType intfn1 = MethodType.methodType(int.class, int.class);
-MethodType intfn2 = MethodType.methodType(int.class, int.class, int.class);
+import static java.lang.invoke.MethodHandles.*;
+import static java.lang.invoke.MethodType.*;
+...
+MethodType intfn1 = methodType(int.class, int.class);
+MethodType intfn2 = methodType(int.class, int.class, int.class);
MethodHandle sub = ... {int x, int y => x-y} ...;
assert(sub.type().equals(intfn2));
-MethodHandle sub1 = MethodHandles.permuteArguments(sub, intfn2, 0, 1);
-MethodHandle rsub = MethodHandles.permuteArguments(sub, intfn2, 1, 0);
+MethodHandle sub1 = permuteArguments(sub, intfn2, 0, 1);
+MethodHandle rsub = permuteArguments(sub, intfn2, 1, 0);
assert((int)rsub.invokeExact(1, 100) == 99);
MethodHandle add = ... {int x, int y => x+y} ...;
assert(add.type().equals(intfn2));
-MethodHandle twice = MethodHandles.permuteArguments(add, intfn1, 0, 0);
+MethodHandle twice = permuteArguments(add, intfn1, 0, 0);
assert(twice.type().equals(intfn1));
assert((int)twice.invokeExact(21) == 42);
* </pre></blockquote>
* @param target the method handle to invoke after arguments are reordered
* @param newType the expected type of the new method handle
- * @param reorder a string which controls the reordering
- * @return a method handle which delegates to {@code target} after it
+ * @param reorder an index array which controls the reordering
+ * @return a method handle which delegates to the target after it
* drops unused arguments and moves and/or duplicates the other arguments
* @throws NullPointerException if any argument is null
+ * @throws IllegalArgumentException if the index array length is not equal to
+ * the arity of the target, or if any index array element
+ * not a valid index for a parameter of {@code newType},
+ * or if two corresponding parameter types in
+ * {@code target.type()} and {@code newType} are not identical,
*/
public static
MethodHandle permuteArguments(MethodHandle target, MethodType newType, int... reorder) {
@@ -1548,78 +1548,13 @@
}
/**
- * Equivalent to the following code:
- * <p><blockquote><pre>
- * int spreadPos = newType.parameterCount() - 1;
- * Class<?> spreadType = newType.parameterType(spreadPos);
- * int spreadCount = target.type().parameterCount() - spreadPos;
- * MethodHandle adapter = target.asSpreader(spreadType, spreadCount);
- * adapter = adapter.asType(newType);
- * return adapter;
- * </pre></blockquote>
- * @param target the method handle to invoke after argument spreading
- * @param newType the expected type of the new method handle
- * @return a method handle which spreads its final argument,
- * before calling the original method handle
- */
- /*non-public*/ static
- MethodHandle spreadArguments(MethodHandle target, MethodType newType) {
- MethodType oldType = target.type();
- int inargs = newType.parameterCount();
- int outargs = oldType.parameterCount();
- int spreadPos = inargs - 1;
- int numSpread = (outargs - spreadPos);
- MethodHandle res = null;
- if (spreadPos >= 0 && numSpread >= 0) {
- res = MethodHandleImpl.spreadArgumentsFromPos(target, newType, spreadPos);
- }
- if (res == null) {
- throw newIllegalArgumentException("cannot spread "+newType+" to " +oldType);
- }
- return res;
- }
-
- /**
- * Equivalent to the following code:
- * <p><blockquote><pre>
- * int collectPos = target.type().parameterCount() - 1;
- * Class<?> collectType = target.type().parameterType(collectPos);
- * if (!collectType.isArray()) collectType = Object[].class;
- * int collectCount = newType.parameterCount() - collectPos;
- * MethodHandle adapter = target.asCollector(collectType, collectCount);
- * adapter = adapter.asType(newType);
- * return adapter;
- * </pre></blockquote>
- * @param target the method handle to invoke after argument collection
- * @param newType the expected type of the new method handle
- * @return a method handle which collects some trailing argument
- * into an array, before calling the original method handle
- */
- /*non-public*/ static
- MethodHandle collectArguments(MethodHandle target, MethodType newType) {
- MethodType oldType = target.type();
- int inargs = newType.parameterCount();
- int outargs = oldType.parameterCount();
- int collectPos = outargs - 1;
- int numCollect = (inargs - collectPos);
- if (collectPos < 0 || numCollect < 0)
- throw newIllegalArgumentException("wrong number of arguments");
- MethodHandle res = MethodHandleImpl.collectArguments(target, newType, collectPos, null);
- if (res == null) {
- throw newIllegalArgumentException("cannot collect from "+newType+" to " +oldType);
- }
- return res;
- }
-
- /**
* Produces a method handle of the requested return type which returns the given
* constant value every time it is invoked.
* <p>
* Before the method handle is returned, the passed-in value is converted to the requested type.
* If the requested type is primitive, widening primitive conversions are attempted,
* else reference conversions are attempted.
- * <p>The returned method handle is equivalent to {@code identity(type).bindTo(value)},
- * unless the type is {@code void}, in which case it is {@code identity(type)}.
+ * <p>The returned method handle is equivalent to {@code identity(type).bindTo(value)}.
* @param type the return type of the desired method handle
* @param value the value to return
* @return a method handle of the given return type and no arguments, which always returns the given value
@@ -1641,7 +1576,6 @@
/**
* Produces a method handle which returns its sole argument when invoked.
- * <p>The identity function for {@code void} takes no arguments and returns no values.
* @param type the type of the sole parameter and return value of the desired method handle
* @return a unary method handle which accepts and returns the given type
* @throws NullPointerException if the argument is null
@@ -1661,11 +1595,15 @@
}
/**
- * Produces a method handle which calls the original method handle {@code target},
- * after inserting the given argument(s) at the given position.
- * The formal parameters to {@code target} which will be supplied by those
- * arguments are called <em>bound parameters</em>, because the new method
- * will contain bindings for those parameters take from {@code values}.
+ * Provides a target method handle with one or more <em>bound arguments</em>
+ * in advance of the method handle's invocation.
+ * The formal parameters to the target corresponding to the bound
+ * arguments are called <em>bound parameters</em>.
+ * Returns a new method handle which saves away the bound arguments.
+ * When it is invoked, it receives arguments for any non-bound parameters,
+ * binds the saved arguments to their corresponding parameters,
+ * and calls the original target.
+ * <p>
* The type of the new method handle will drop the types for the bound
* parameters from the original target type, since the new method handle
* will no longer require those arguments to be supplied by its callers.
@@ -1674,15 +1612,16 @@
* If a bound parameter type is a primitive, the argument object
* must be a wrapper, and will be unboxed to produce the primitive value.
* <p>
- * The <i>pos</i> may range between zero and <i>N</i> (inclusively),
- * where <i>N</i> is the number of argument types in resulting method handle
- * (after bound parameter types are dropped).
+ * The {@code pos} argument selects which parameters are to be bound.
+ * It may range between zero and <i>N-L</i> (inclusively),
+ * where <i>N</i> is the arity of the target method handle
+ * and <i>L</i> is the length of the values array.
* @param target the method handle to invoke after the argument is inserted
* @param pos where to insert the argument (zero for the first)
* @param values the series of arguments to insert
* @return a method handle which inserts an additional argument,
* before calling the original method handle
- * @throws NullPointerException if the {@code target} argument or the {@code values} array is null
+ * @throws NullPointerException if the target or the {@code values} array is null
* @see MethodHandle#bindTo
*/
public static
@@ -1715,15 +1654,17 @@
}
/**
- * Produces a method handle which calls the original method handle,
- * after dropping the given argument(s) at the given position.
- * The type of the new method handle will insert the given argument
- * type(s), at that position, into the original handle's type.
+ * Produces a method handle which will discard some dummy arguments
+ * before calling some other specified <i>target</i> method handle.
+ * The type of the new method handle will be the same as the target's type,
+ * except it will also include the dummy argument types,
+ * at some given position.
* <p>
- * The <i>pos</i> may range between zero and <i>N</i>,
- * where <i>N</i> is the number of argument types in <i>target</i>,
- * meaning to drop the first or last argument (respectively),
- * or an argument somewhere in between.
+ * The {@code pos} argument may range between zero and <i>N</i>,
+ * where <i>N</i> is the arity of the target.
+ * If {@code pos} is zero, the dummy arguments will precede
+ * the target's real arguments; if {@code pos} is <i>N</i>
+ * they will come after.
* <p>
* <b>Example:</b>
* <p><blockquote><pre>
@@ -1748,14 +1689,16 @@
* @param pos position of first argument to drop (zero for the leftmost)
* @return a method handle which drops arguments of the given types,
* before calling the original method handle
- * @throws NullPointerException if the {@code target} argument is null,
+ * @throws NullPointerException if the target is null,
* or if the {@code valueTypes} list or any of its elements is null
- * @throws IllegalArgumentException if any of the {@code valueTypes} is {@code void.class}
+ * @throws IllegalArgumentException if any element of {@code valueTypes} is {@code void.class},
+ * or if {@code pos} is negative or greater than the arity of the target,
+ * or if the new method handle's type would have too many parameters
*/
public static
MethodHandle dropArguments(MethodHandle target, int pos, List<Class<?>> valueTypes) {
+ MethodType oldType = target.type(); // get NPE
if (valueTypes.size() == 0) return target;
- MethodType oldType = target.type();
int outargs = oldType.parameterCount();
int inargs = outargs + valueTypes.size();
if (pos < 0 || pos >= inargs)
@@ -1768,15 +1711,17 @@
}
/**
- * Produces a method handle which calls the original method handle,
- * after dropping the given argument(s) at the given position.
- * The type of the new method handle will insert the given argument
- * type(s), at that position, into the original handle's type.
+ * Produces a method handle which will discard some dummy arguments
+ * before calling some other specified <i>target</i> method handle.
+ * The type of the new method handle will be the same as the target's type,
+ * except it will also include the dummy argument types,
+ * at some given position.
* <p>
- * The <i>pos</i> may range between zero and <i>N</i>,
- * where <i>N</i> is the number of argument types in <i>target</i>,
- * meaning to drop the first or last argument (respectively),
- * or an argument somewhere in between.
+ * The {@code pos} argument may range between zero and <i>N</i>,
+ * where <i>N</i> is the arity of the target.
+ * If {@code pos} is zero, the dummy arguments will precede
+ * the target's real arguments; if {@code pos} is <i>N</i>
+ * they will come after.
* <p>
* <b>Example:</b>
* <p><blockquote><pre>
@@ -1805,9 +1750,11 @@
* @param pos position of first argument to drop (zero for the leftmost)
* @return a method handle which drops arguments of the given types,
* before calling the original method handle
- * @throws NullPointerException if the {@code target} argument is null,
+ * @throws NullPointerException if the target is null,
* or if the {@code valueTypes} array or any of its elements is null
- * @throws IllegalArgumentException if any of the {@code valueTypes} is {@code void.class}
+ * @throws IllegalArgumentException if any element of {@code valueTypes} is {@code void.class},
+ * or if {@code pos} is negative or greater than the arity of the target,
+ * or if the new method handle's type would have too many parameters
*/
public static
MethodHandle dropArguments(MethodHandle target, int pos, Class<?>... valueTypes) {
@@ -1815,19 +1762,23 @@
}
/**
- * Adapts a target method handle {@code target} by pre-processing
+ * Adapts a target method handle by pre-processing
* one or more of its arguments, each with its own unary filter function,
* and then calling the target with each pre-processed argument
* replaced by the result of its corresponding filter function.
* <p>
* The pre-processing is performed by one or more method handles,
* specified in the elements of the {@code filters} array.
- * Null arguments in the array are ignored, and the corresponding arguments left unchanged.
+ * The first element of the filter array corresponds to the {@code pos}
+ * argument of the target, and so on in sequence.
+ * <p>
+ * Null arguments in the array are treated as identity functions,
+ * and the corresponding arguments left unchanged.
* (If there are no non-null elements in the array, the original target is returned.)
* Each filter is applied to the corresponding argument of the adapter.
* <p>
* If a filter {@code F} applies to the {@code N}th argument of
- * the method handle, then {@code F} must be a method handle which
+ * the target, then {@code F} must be a method handle which
* takes exactly one argument. The type of {@code F}'s sole argument
* replaces the corresponding argument type of the target
* in the resulting adapted method handle.
@@ -1835,6 +1786,7 @@
* parameter type of the target.
* <p>
* It is an error if there are elements of {@code filters}
+ * (null or not)
* which do not correspond to argument positions in the target.
* <b>Example:</b>
* <p><blockquote><pre>
@@ -1853,15 +1805,23 @@
MethodHandle f2 = filterArguments(cat, 0, upcase, upcase);
assertEquals("XY", (String) f2.invokeExact("x", "y")); // XY
* </pre></blockquote>
+ * <p> Here is pseudocode for the resulting adapter:
+ * <blockquote><pre>
+ * V target(P... p, A[i]... a[i], B... b);
+ * A[i] filter[i](V[i]);
+ * T adapter(P... p, V[i]... v[i], B... b) {
+ * return target(p..., f[i](v[i])..., b...);
+ * }
+ * </pre></blockquote>
*
* @param target the method handle to invoke after arguments are filtered
* @param pos the position of the first argument to filter
* @param filters method handles to call initially on filtered arguments
* @return method handle which incorporates the specified argument filtering logic
- * @throws NullPointerException if the {@code target} argument is null
+ * @throws NullPointerException if the target is null
* or if the {@code filters} array is null
* @throws IllegalArgumentException if a non-null element of {@code filters}
- * does not match a corresponding argument type of {@code target} as described above,
+ * does not match a corresponding argument type of target as described above,
* or if the {@code pos+filters.length} is greater than {@code target.type().parameterCount()}
*/
public static
@@ -1895,15 +1855,18 @@
}
/**
- * Adapts a target method handle {@code target} by post-processing
- * its return value with a unary filter function.
+ * Adapts a target method handle by post-processing
+ * its return value (if any) with a filter (another method handle).
+ * The result of the filter is returned from the adapter.
* <p>
- * If a filter {@code F} applies to the return value of
- * the target method handle, then {@code F} must be a method handle which
- * takes exactly one argument. The return type of {@code F}
+ * If the target returns a value, the filter must accept that value as
+ * its only argument.
+ * If the target returns void, the filter must accept no arguments.
+ * <p>
+ * The return type of the filter
* replaces the return type of the target
* in the resulting adapted method handle.
- * The argument type of {@code F} must be identical to the
+ * The argument type of the filter (if any) must be identical to the
* return type of the target.
* <b>Example:</b>
* <p><blockquote><pre>
@@ -1918,12 +1881,35 @@
MethodHandle f0 = filterReturnValue(cat, length);
System.out.println((int) f0.invokeExact("x", "y")); // 2
* </pre></blockquote>
+ * <p> Here is pseudocode for the resulting adapter:
+ * <blockquote><pre>
+ * V target(A...);
+ * T filter(V);
+ * T adapter(A... a) {
+ * V v = target(a...);
+ * return filter(v);
+ * }
+ * // and if the target has a void return:
+ * void target2(A...);
+ * T filter2();
+ * T adapter2(A... a) {
+ * target2(a...);
+ * return filter2();
+ * }
+ * // and if the filter has a void return:
+ * V target3(A...);
+ * void filter3(V);
+ * void adapter3(A... a) {
+ * V v = target3(a...);
+ * filter3(v);
+ * }
+ * </pre></blockquote>
* @param target the method handle to invoke before filtering the return value
* @param filter method handle to call on the return value
* @return method handle which incorporates the specified return value filtering logic
* @throws NullPointerException if either argument is null
- * @throws IllegalArgumentException if {@code filter}
- * does not match the return type of {@code target} as described above
+ * @throws IllegalArgumentException if the argument list of {@code filter}
+ * does not match the return type of target as described above
*/
public static
MethodHandle filterReturnValue(MethodHandle target, MethodHandle filter) {
@@ -1952,55 +1938,87 @@
}
/**
- * Adapts a target method handle {@code target} by pre-processing
+ * Adapts a target method handle by pre-processing
* some of its arguments, and then calling the target with
- * the result of the pre-processing, plus all original arguments.
+ * the result of the pre-processing, inserted into the original
+ * sequence of arguments.
+ * <p>
+ * The pre-processing is performed by {@code combiner}, a second method handle.
+ * Of the arguments passed to the adapter, the first {@code N} arguments
+ * are copied to the combiner, which is then called.
+ * (Here, {@code N} is defined as the parameter count of the combiner.)
+ * After this, control passes to the target, with any result
+ * from the combiner inserted before the original {@code N} incoming
+ * arguments.
* <p>
- * The pre-processing is performed by a second method handle, the {@code combiner}.
- * The first {@code N} arguments passed to the adapter,
- * are copied to the combiner, which then produces a result.
- * (Here, {@code N} is defined as the parameter count of the adapter.)
- * After this, control passes to the {@code target}, with both the result
- * of the combiner, and all the original incoming arguments.
+ * If the combiner returns a value, the first parameter type of the target
+ * must be identical with the return type of the combiner, and the next
+ * {@code N} parameter types of the target must exactly match the parameters
+ * of the combiner.
* <p>
- * The first argument type of the target must be identical with the
- * return type of the combiner.
+ * If the combiner has a void return, no result will be inserted,
+ * and the first {@code N} parameter types of the target
+ * must exactly match the parameters of the combiner.
+ * <p>
* The resulting adapter is the same type as the target, except that the
- * initial argument type of the target is dropped.
+ * first parameter type is dropped,
+ * if it corresponds to the result of the combiner.
* <p>
* (Note that {@link #dropArguments(MethodHandle,int,List) dropArguments} can be used to remove any arguments
- * that either the {@code combiner} or {@code target} does not wish to receive.
+ * that either the combiner or the target does not wish to receive.
* If some of the incoming arguments are destined only for the combiner,
* consider using {@link MethodHandle#asCollector asCollector} instead, since those
* arguments will not need to be live on the stack on entry to the
* target.)
- * <p>
- * The first argument of the target must be identical with the
- * return value of the combiner.
+ * <b>Example:</b>
+ * <p><blockquote><pre>
+import static java.lang.invoke.MethodHandles.*;
+import static java.lang.invoke.MethodType.*;
+...
+MethodHandle trace = publicLookup().findVirtual(java.io.PrintStream.class,
+ "println", methodType(void.class, String.class))
+ .bindTo(System.out);
+MethodHandle cat = lookup().findVirtual(String.class,
+ "concat", methodType(String.class, String.class));
+assertEquals("boojum", (String) cat.invokeExact("boo", "jum"));
+MethodHandle catTrace = foldArguments(cat, trace);
+// also prints "boo":
+assertEquals("boojum", (String) catTrace.invokeExact("boo", "jum"));
+ * </pre></blockquote>
* <p> Here is pseudocode for the resulting adapter:
* <blockquote><pre>
- * // there are N arguments in the A sequence
+ * // there are N arguments in A...
* T target(V, A[N]..., B...);
* V combiner(A...);
* T adapter(A... a, B... b) {
* V v = combiner(a...);
* return target(v, a..., b...);
* }
+ * // and if the combiner has a void return:
+ * T target2(A[N]..., B...);
+ * void combiner2(A...);
+ * T adapter2(A... a, B... b) {
+ * combiner2(a...);
+ * return target2(a..., b...);
+ * }
* </pre></blockquote>
* @param target the method handle to invoke after arguments are combined
* @param combiner method handle to call initially on the incoming arguments
* @return method handle which incorporates the specified argument folding logic
* @throws NullPointerException if either argument is null
- * @throws IllegalArgumentException if the first argument type of
- * {@code target} is not the same as {@code combiner}'s return type,
- * or if the following argument types of {@code target}
+ * @throws IllegalArgumentException if {@code combiner}'s return type
+ * is non-void and not the same as the first argument type of
+ * the target, or if the initial {@code N} argument types
+ * of the target
+ * (skipping one matching the {@code combiner}'s return type)
* are not identical with the argument types of {@code combiner}
*/
public static
MethodHandle foldArguments(MethodHandle target, MethodHandle combiner) {
+ int pos = 0;
MethodType targetType = target.type();
MethodType combinerType = combiner.type();
- int foldPos = 0; // always at the head, at present
+ int foldPos = pos;
int foldArgs = combinerType.parameterCount();
int foldVals = combinerType.returnType() == void.class ? 0 : 1;
int afterInsertPos = foldPos + foldVals;
@@ -2049,7 +2067,7 @@
* @throws NullPointerException if any argument is null
* @throws IllegalArgumentException if {@code test} does not return boolean,
* or if all three method types do not match (with the return
- * type of {@code test} changed to match that of {@code target}).
+ * type of {@code test} changed to match that of the target).
*/
public static
MethodHandle guardWithTest(MethodHandle test,
@@ -2159,229 +2177,4 @@
MethodHandle throwException(Class<?> returnType, Class<? extends Throwable> exType) {
return MethodHandleImpl.throwException(MethodType.methodType(returnType, exType));
}
-
- /**
- * Produces an instance of the given single-method interface which redirects
- * its calls to the given method handle.
- * <p>
- * A single-method interface is an interface which declares a unique method.
- * When determining the unique method of a single-method interface,
- * the public {@code Object} methods ({@code toString}, {@code equals}, {@code hashCode})
- * are disregarded. For example, {@link java.util.Comparator} is a single-method interface,
- * even though it re-declares the {@code Object.equals} method.
- * <p>
- * The type must be public. No additional access checks are performed.
- * <p>
- * The resulting instance of the required type will respond to
- * invocation of the type's single abstract method by calling
- * the given {@code target} on the incoming arguments,
- * and returning or throwing whatever the {@code target}
- * returns or throws. The invocation will be as if by
- * {@code target.invoke}.
- * The target's type will be checked before the
- * instance is created, as if by a call to {@code asType},
- * which may result in a {@code WrongMethodTypeException}.
- * <p>
- * The wrapper instance will implement the requested interface
- * and its super-types, but no other single-method interfaces.
- * This means that the instance will not unexpectedly
- * pass an {@code instanceof} test for any unrequested type.
- * <p style="font-size:smaller;">
- * <em>Implementation Note:</em>
- * Therefore, each instance must implement a unique single-method interface.
- * Implementations may not bundle together
- * multiple single-method interfaces onto single implementation classes
- * in the style of {@link java.awt.AWTEventMulticaster}.
- * <p>
- * The method handle may throw an <em>undeclared exception</em>,
- * which means any checked exception (or other checked throwable)
- * not declared by the requested type's single abstract method.
- * If this happens, the throwable will be wrapped in an instance of
- * {@link java.lang.reflect.UndeclaredThrowableException UndeclaredThrowableException}
- * and thrown in that wrapped form.
- * <p>
- * Like {@link java.lang.Integer#valueOf Integer.valueOf},
- * {@code asInstance} is a factory method whose results are defined
- * by their behavior.
- * It is not guaranteed to return a new instance for every call.
- * <p>
- * Because of the possibility of {@linkplain java.lang.reflect.Method#isBridge bridge methods}
- * and other corner cases, the interface may also have several abstract methods
- * with the same name but having distinct descriptors (types of returns and parameters).
- * In this case, all the methods are bound in common to the one given {@code target}.
- * The type check and effective {@code asType} conversion is applied to each
- * method type descriptor, and all abstract methods are bound to the {@code target} in common.
- * Beyond this type check, no further checks are made to determine that the
- * abstract methods are related in any way.
- * <p>
- * Future versions of this API may accept additional types,
- * such as abstract classes with single abstract methods.
- * Future versions of this API may also equip wrapper instances
- * with one or more additional public "marker" interfaces.
- *
- * @param target the method handle to invoke from the wrapper
- * @param smType the desired type of the wrapper, a single-method interface
- * @return a correctly-typed wrapper for the given {@code target}
- * @throws NullPointerException if either argument is null
- * @throws IllegalArgumentException if the {@code smType} is not a
- * valid argument to this method
- * @throws WrongMethodTypeException if the {@code target} cannot
- * be converted to the type required by the requested interface
- */
- // Other notes to implementors:
- // <p>
- // No stable mapping is promised between the single-method interface and
- // the implementation class C. Over time, several implementation
- // classes might be used for the same type.
- // <p>
- // If the implementation is able
- // to prove that a wrapper of the required type
- // has already been created for a given
- // method handle, or for another method handle with the
- // same behavior, the implementation may return that wrapper in place of
- // a new wrapper.
- // <p>
- // This method is designed to apply to common use cases
- // where a single method handle must interoperate with
- // an interface that implements a function-like
- // API. Additional variations, such as single-abstract-method classes with
- // private constructors, or interfaces with multiple but related
- // entry points, must be covered by hand-written or automatically
- // generated adapter classes.
- //
- public static
- <T> T asInstance(final MethodHandle target, final Class<T> smType) {
- // POC implementation only; violates the above contract several ways
- final Method sm = getSingleMethod(smType);
- if (sm == null)
- throw new IllegalArgumentException("not a single-method interface: "+smType.getName());
- MethodType smMT = MethodType.methodType(sm.getReturnType(), sm.getParameterTypes());
- MethodHandle checkTarget = target.asType(smMT); // make throw WMT
- checkTarget = checkTarget.asType(checkTarget.type().changeReturnType(Object.class));
- final MethodHandle vaTarget = checkTarget.asSpreader(Object[].class, smMT.parameterCount());
- return smType.cast(Proxy.newProxyInstance(
- smType.getClassLoader(),
- new Class[]{ smType, WrapperInstance.class },
- new InvocationHandler() {
- private Object getArg(String name) {
- if ((Object)name == "getWrapperInstanceTarget") return target;
- if ((Object)name == "getWrapperInstanceType") return smType;
- throw new AssertionError();
- }
- public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
- if (method.getDeclaringClass() == WrapperInstance.class)
- return getArg(method.getName());
- if (method.equals(sm))
- return vaTarget.invokeExact(args);
- if (isObjectMethod(method))
- return callObjectMethod(this, method, args);
- throw new InternalError();
- }
- }));
- }
-
- /**
- * Determines if the given object was produced by a call to {@link #asInstance asInstance}.
- * @param x any reference
- * @return true if the reference is not null and points to an object produced by {@code asInstance}
- */
- public static
- boolean isWrapperInstance(Object x) {
- return x instanceof WrapperInstance;
- }
-
- private static WrapperInstance asWrapperInstance(Object x) {
- try {
- if (x != null)
- return (WrapperInstance) x;
- } catch (ClassCastException ex) {
- }
- throw new IllegalArgumentException("not a wrapper instance");
- }
-
- /**
- * Produces or recovers a target method handle which is behaviorally
- * equivalent to the unique method of this wrapper instance.
- * The object {@code x} must have been produced by a call to {@link #asInstance asInstance}.
- * This requirement may be tested via {@link #isWrapperInstance isWrapperInstance}.
- * @param x any reference
- * @return a method handle implementing the unique method
- * @throws IllegalArgumentException if the reference x is not to a wrapper instance
- */
- public static
- MethodHandle wrapperInstanceTarget(Object x) {
- return asWrapperInstance(x).getWrapperInstanceTarget();
- }
-
- /**
- * Recovers the unique single-method interface type for which this wrapper instance was created.
- * The object {@code x} must have been produced by a call to {@link #asInstance asInstance}.
- * This requirement may be tested via {@link #isWrapperInstance isWrapperInstance}.
- * @param x any reference
- * @return the single-method interface type for which the wrapper was created
- * @throws IllegalArgumentException if the reference x is not to a wrapper instance
- */
- public static
- Class<?> wrapperInstanceType(Object x) {
- return asWrapperInstance(x).getWrapperInstanceType();
- }
-
- private static
- boolean isObjectMethod(Method m) {
- switch (m.getName()) {
- case "toString":
- return (m.getReturnType() == String.class
- && m.getParameterTypes().length == 0);
- case "hashCode":
- return (m.getReturnType() == int.class
- && m.getParameterTypes().length == 0);
- case "equals":
- return (m.getReturnType() == boolean.class
- && m.getParameterTypes().length == 1
- && m.getParameterTypes()[0] == Object.class);
- }
- return false;
- }
-
- private static
- Object callObjectMethod(Object self, Method m, Object[] args) {
- assert(isObjectMethod(m)) : m;
- switch (m.getName()) {
- case "toString":
- return self.getClass().getName() + "@" + Integer.toHexString(self.hashCode());
- case "hashCode":
- return System.identityHashCode(self);
- case "equals":
- return (self == args[0]);
- }
- return null;
- }
-
- private static
- Method getSingleMethod(Class<?> smType) {
- Method sm = null;
- for (Method m : smType.getMethods()) {
- int mod = m.getModifiers();
- if (Modifier.isAbstract(mod)) {
- if (sm != null && !isObjectMethod(sm))
- return null; // too many abstract methods
- sm = m;
- }
- }
- if (!smType.isInterface() && getSingleConstructor(smType) == null)
- return null; // wrong kind of constructor
- return sm;
- }
-
- private static
- Constructor getSingleConstructor(Class<?> smType) {
- for (Constructor c : smType.getDeclaredConstructors()) {
- if (c.getParameterTypes().length == 0) {
- int mod = c.getModifiers();
- if (Modifier.isPublic(mod) || Modifier.isProtected(mod))
- return c;
- }
- }
- return null;
- }
}
--- a/jdk/src/share/classes/java/lang/invoke/MethodType.java Thu May 26 20:20:03 2011 -0700
+++ b/jdk/src/share/classes/java/lang/invoke/MethodType.java Fri May 27 19:03:03 2011 -0700
@@ -273,7 +273,7 @@
* @param objectArgCount number of parameters (excluding the final array parameter if any)
* @param finalArray whether there will be a trailing array parameter, of type {@code Object[]}
* @return a generally applicable method type, for all calls of the given fixed argument count and a collected array of further arguments
- * @throws IllegalArgumentException if {@code objectArgCount} is negative or greater than 255 (or 254, if {@code finalArray})
+ * @throws IllegalArgumentException if {@code objectArgCount} is negative or greater than 255 (or 254, if {@code finalArray} is true)
* @see #genericMethodType(int)
*/
public static
@@ -455,7 +455,8 @@
/**
* Reports if this type contains a wrapper argument or return value.
* Wrappers are types which box primitive values, such as {@link Integer}.
- * The reference type {@code java.lang.Void} counts as a wrapper.
+ * The reference type {@code java.lang.Void} counts as a wrapper,
+ * if it occurs as a return type.
* @return true if any of the types are wrappers
*/
public boolean hasWrappers() {
@@ -649,13 +650,55 @@
}
/*non-public*/
static boolean canConvert(Class<?> src, Class<?> dst) {
- if (src == dst || dst == void.class) return true;
- if (src.isPrimitive() && dst.isPrimitive()) {
- if (!Wrapper.forPrimitiveType(dst)
- .isConvertibleFrom(Wrapper.forPrimitiveType(src)))
+ // short-circuit a few cases:
+ if (src == dst || dst == Object.class) return true;
+ // the remainder of this logic is documented in MethodHandle.asType
+ if (src.isPrimitive()) {
+ // can force void to an explicit null, a la reflect.Method.invoke
+ // can also force void to a primitive zero, by analogy
+ if (src == void.class) return true; //or !dst.isPrimitive()?
+ Wrapper sw = Wrapper.forPrimitiveType(src);
+ if (dst.isPrimitive()) {
+ // P->P must widen
+ return Wrapper.forPrimitiveType(dst).isConvertibleFrom(sw);
+ } else {
+ // P->R must box and widen
+ return dst.isAssignableFrom(sw.wrapperType());
+ }
+ } else if (dst.isPrimitive()) {
+ // any value can be dropped
+ if (dst == void.class) return true;
+ Wrapper dw = Wrapper.forPrimitiveType(dst);
+ // R->P must be able to unbox (from a dynamically chosen type) and widen
+ // For example:
+ // Byte/Number/Comparable/Object -> dw:Byte -> byte.
+ // Character/Comparable/Object -> dw:Character -> char
+ // Boolean/Comparable/Object -> dw:Boolean -> boolean
+ // This means that dw must be cast-compatible with src.
+ if (src.isAssignableFrom(dw.wrapperType())) {
+ return true;
+ }
+ // The above does not work if the source reference is strongly typed
+ // to a wrapper whose primitive must be widened. For example:
+ // Byte -> unbox:byte -> short/int/long/float/double
+ // Character -> unbox:char -> int/long/float/double
+ if (Wrapper.isWrapperType(src) &&
+ dw.isConvertibleFrom(Wrapper.forWrapperType(src))) {
+ // can unbox from src and then widen to dst
+ return true;
+ }
+ // We have already covered cases which arise due to runtime unboxing
+ // of a reference type which covers several wrapper types:
+ // Object -> cast:Integer -> unbox:int -> long/float/double
+ // Serializable -> cast:Byte -> unbox:byte -> byte/short/int/long/float/double
+ // An marginal case is Number -> dw:Character -> char, which would be OK if there were a
+ // subclass of Number which wraps a value that can convert to char.
+ // Since there is none, we don't need an extra check here to cover char or boolean.
return false;
+ } else {
+ // R->R always works, since null is always valid dynamically
+ return true;
}
- return true;
}
/// Queries which have to do with the bytecode architecture
@@ -740,6 +783,7 @@
* @param descriptor a bytecode-level type descriptor string "(T...)T"
* @param loader the class loader in which to look up the types
* @return a method type matching the bytecode-level type descriptor
+ * @throws NullPointerException if the string is null
* @throws IllegalArgumentException if the string is not well-formed
* @throws TypeNotPresentException if a named type cannot be found
*/
--- a/jdk/src/share/classes/java/lang/invoke/MutableCallSite.java Thu May 26 20:20:03 2011 -0700
+++ b/jdk/src/share/classes/java/lang/invoke/MutableCallSite.java Fri May 27 19:03:03 2011 -0700
@@ -37,12 +37,13 @@
* <p>
* Here is an example of a mutable call site which introduces a
* state variable into a method handle chain.
+ * <!-- JavaDocExamplesTest.testMutableCallSite -->
* <blockquote><pre>
MutableCallSite name = new MutableCallSite(MethodType.methodType(String.class));
MethodHandle MH_name = name.dynamicInvoker();
-MethodType MT_str2 = MethodType.methodType(String.class, String.class);
+MethodType MT_str1 = MethodType.methodType(String.class);
MethodHandle MH_upcase = MethodHandles.lookup()
- .findVirtual(String.class, "toUpperCase", MT_str2);
+ .findVirtual(String.class, "toUpperCase", MT_str1);
MethodHandle worker1 = MethodHandles.filterReturnValue(MH_name, MH_upcase);
name.setTarget(MethodHandles.constant(String.class, "Rocky"));
assertEquals("ROCKY", (String) worker1.invokeExact());
@@ -53,8 +54,10 @@
* <p>
* The same call site may be used in several places at once.
* <blockquote><pre>
-MethodHandle MH_dear = MethodHandles.lookup()
- .findVirtual(String.class, "concat", MT_str2).bindTo(", dear?");
+MethodType MT_str2 = MethodType.methodType(String.class, String.class);
+MethodHandle MH_cat = lookup().findVirtual(String.class,
+ "concat", methodType(String.class, String.class));
+MethodHandle MH_dear = MethodHandles.insertArguments(MH_cat, 1, ", dear?");
MethodHandle worker2 = MethodHandles.filterReturnValue(MH_name, MH_dear);
assertEquals("Fred, dear?", (String) worker2.invokeExact());
name.setTarget(MethodHandles.constant(String.class, "Wilma"));
--- a/jdk/src/share/classes/java/lang/invoke/SwitchPoint.java Thu May 26 20:20:03 2011 -0700
+++ b/jdk/src/share/classes/java/lang/invoke/SwitchPoint.java Fri May 27 19:03:03 2011 -0700
@@ -56,16 +56,17 @@
* <p>
* Here is an example of a switch point in action:
* <blockquote><pre>
-MethodType MT_str2 = MethodType.methodType(String.class, String.class);
MethodHandle MH_strcat = MethodHandles.lookup()
- .findVirtual(String.class, "concat", MT_str2);
+ .findVirtual(String.class, "concat", MethodType.methodType(String.class, String.class));
SwitchPoint spt = new SwitchPoint();
+assert(spt.isValid());
// the following steps may be repeated to re-use the same switch point:
-MethodHandle worker1 = strcat;
-MethodHandle worker2 = MethodHandles.permuteArguments(strcat, MT_str2, 1, 0);
+MethodHandle worker1 = MH_strcat;
+MethodHandle worker2 = MethodHandles.permuteArguments(MH_strcat, MH_strcat.type(), 1, 0);
MethodHandle worker = spt.guardWithTest(worker1, worker2);
assertEquals("method", (String) worker.invokeExact("met", "hod"));
SwitchPoint.invalidateAll(new SwitchPoint[]{ spt });
+assert(!spt.isValid());
assertEquals("hodmet", (String) worker.invokeExact("met", "hod"));
* </pre></blockquote>
* <p style="font-size:smaller;">
@@ -125,6 +126,19 @@
}
/**
+ * Determines if this switch point is still valid.
+ * <p>
+ * Since invalidation is a global and immediate operation,
+ * this query must be sequenced with any
+ * other threads that could invalidate this switch point.
+ * It may therefore be expensive.
+ * @return true if this switch point has never been invalidated
+ */
+ public boolean isValid() {
+ return (mcs.getTarget() == K_true);
+ }
+
+ /**
* Returns a method handle which always delegates either to the target or the fallback.
* The method handle will delegate to the target exactly as long as the switch point is valid.
* After that, it will permanently delegate to the fallback.
@@ -136,6 +150,7 @@
* @param fallback the method handle selected by the switch point after it is invalidated
* @return a combined method handle which always calls either the target or fallback
* @throws NullPointerException if either argument is null
+ * @throws IllegalArgumentException if the two method types do not match
* @see MethodHandles#guardWithTest
*/
public MethodHandle guardWithTest(MethodHandle target, MethodHandle fallback) {
--- a/jdk/src/share/classes/java/lang/invoke/package-info.java Thu May 26 20:20:03 2011 -0700
+++ b/jdk/src/share/classes/java/lang/invoke/package-info.java Fri May 27 19:03:03 2011 -0700
@@ -28,7 +28,8 @@
* the Java core class libraries and virtual machine.
*
* <p>
- * Certain types in this package have special relations to dynamic
+ * As described in the Java Virtual Machine Specification,
+ * certain types in this package have special relations to dynamic
* language support in the virtual machine:
* <ul>
* <li>The class {@link java.lang.invoke.MethodHandle MethodHandle} contains
@@ -42,177 +43,16 @@
* </li>
* </ul>
*
- * <h2><a name="jvm_mods"></a>Corresponding JVM bytecode format changes</h2>
- * <em>The following low-level information is presented here as a preview of
- * changes being made to the Java Virtual Machine specification for JSR 292.
- * This information will be incorporated in a future version of the JVM specification.</em>
+ * <h2><a name="jvm_mods"></a>Summary of relevant Java Virtual Machine changes</h2>
+ * The following low-level information summarizes relevant parts of the
+ * Java Virtual Machine specification. For full details, please see the
+ * current version of that specification.
*
- * <h3><a name="indyinsn"></a>{@code invokedynamic} instruction format</h3>
- * In bytecode, an {@code invokedynamic} instruction is formatted as five bytes.
- * The first byte is the opcode 186 (hexadecimal {@code BA}).
- * The next two bytes are a constant pool index (in the same format as for the other {@code invoke} instructions).
- * The final two bytes are reserved for future use and required to be zero.
- * The constant pool reference of an {@code invokedynamic} instruction is to a entry
- * with tag {@code CONSTANT_InvokeDynamic} (decimal 18). See below for its format.
- * The entry specifies the following information:
- * <ul>
- * <li>a bootstrap method (a {@link java.lang.invoke.MethodHandle MethodHandle} constant)</li>
- * <li>the dynamic invocation name (a UTF8 string)</li>
- * <li>the argument and return types of the call (encoded as a type descriptor in a UTF8 string)</li>
- * <li>optionally, a sequence of additional <em>static arguments</em> to the bootstrap method ({@code ldc}-type constants)</li>
- * </ul>
- * <p>
- * Each instance of an {@code invokedynamic} instruction is called a <em>dynamic call site</em>.
- * Multiple instances of an {@code invokedynamic} instruction can share a single
- * {@code CONSTANT_InvokeDynamic} entry.
- * In any case, distinct call sites always have distinct linkage state.
- * <p>
+ * Each occurrence of an {@code invokedynamic} instruction is called a <em>dynamic call site</em>.
+ * <h3><a name="indyinsn"></a>{@code invokedynamic} instructions</h3>
* A dynamic call site is originally in an unlinked state. In this state, there is
* no target method for the call site to invoke.
- * A dynamic call site is linked by means of a bootstrap method,
- * as <a href="#bsm">described below</a>.
- *
- * <h3><a name="indycon"></a>constant pool entries for {@code invokedynamic} instructions</h3>
- * If a constant pool entry has the tag {@code CONSTANT_InvokeDynamic} (decimal 18),
- * it must contain exactly four more bytes after the tag.
- * These bytes are interpreted as two 16-bit indexes, in the usual {@code u2} format.
- * The first pair of bytes after the tag must be an index into a side table called the
- * <em>bootstrap method table</em>, which is stored in the {@code BootstrapMethods}
- * attribute as <a href="#bsmattr">described below</a>.
- * The second pair of bytes must be an index to a {@code CONSTANT_NameAndType}.
* <p>
- * The first index specifies a bootstrap method used by the associated dynamic call sites.
- * The second index specifies the method name, argument types, and return type of the dynamic call site.
- * The structure of such an entry is therefore analogous to a {@code CONSTANT_Methodref},
- * except that the bootstrap method specifier reference replaces
- * the {@code CONSTANT_Class} reference of a {@code CONSTANT_Methodref} entry.
- *
- * <h3><a name="mtcon"></a>constant pool entries for {@linkplain java.lang.invoke.MethodType method types}</h3>
- * If a constant pool entry has the tag {@code CONSTANT_MethodType} (decimal 16),
- * it must contain exactly two more bytes, which must be an index to a {@code CONSTANT_Utf8}
- * entry which represents a method type descriptor.
- * <p>
- * The JVM will ensure that on first
- * execution of an {@code ldc} instruction for this entry, a {@link java.lang.invoke.MethodType MethodType}
- * will be created which represents the type descriptor.
- * Any classes mentioned in the {@code MethodType} will be loaded if necessary,
- * but not initialized.
- * Access checking and error reporting is performed exactly as it is for
- * references by {@code ldc} instructions to {@code CONSTANT_Class} constants.
- *
- * <h3><a name="mhcon"></a>constant pool entries for {@linkplain java.lang.invoke.MethodHandle method handles}</h3>
- * If a constant pool entry has the tag {@code CONSTANT_MethodHandle} (decimal 15),
- * it must contain exactly three more bytes. The first byte after the tag is a subtag
- * value which must be in the range 1 through 9, and the last two must be an index to a
- * {@code CONSTANT_Fieldref}, {@code CONSTANT_Methodref}, or
- * {@code CONSTANT_InterfaceMethodref} entry which represents a field or method
- * for which a method handle is to be created.
- * Furthermore, the subtag value and the type of the constant index value
- * must agree according to the table below.
- * <p>
- * The JVM will ensure that on first execution of an {@code ldc} instruction
- * for this entry, a {@link java.lang.invoke.MethodHandle MethodHandle} will be created which represents
- * the field or method reference, according to the specific mode implied by the subtag.
- * <p>
- * As with {@code CONSTANT_Class} and {@code CONSTANT_MethodType} constants,
- * the {@code Class} or {@code MethodType} object which reifies the field or method's
- * type is created. Any classes mentioned in this reification will be loaded if necessary,
- * but not initialized, and access checking and error reporting performed as usual.
- * <p>
- * Unlike the reflective {@code Lookup} API, there are no security manager calls made
- * when these constants are resolved.
- * <p>
- * The method handle itself will have a type and behavior determined by the subtag as follows:
- * <code>
- * <table border=1 cellpadding=5 summary="CONSTANT_MethodHandle subtypes">
- * <tr><th>N</th><th>subtag name</th><th>member</th><th>MH type</th><th>bytecode behavior</th><th>lookup expression</th></tr>
- * <tr><td>1</td><td>REF_getField</td><td>C.f:T</td><td>(C)T</td><td>getfield C.f:T</td>
- * <td>{@linkplain java.lang.invoke.MethodHandles.Lookup#findGetter findGetter(C.class,"f",T.class)}</td></tr>
- * <tr><td>2</td><td>REF_getStatic</td><td>C.f:T</td><td>( )T</td><td>getstatic C.f:T</td>
- * <td>{@linkplain java.lang.invoke.MethodHandles.Lookup#findStaticGetter findStaticGetter(C.class,"f",T.class)}</td></tr>
- * <tr><td>3</td><td>REF_putField</td><td>C.f:T</td><td>(C,T)void</td><td>putfield C.f:T</td>
- * <td>{@linkplain java.lang.invoke.MethodHandles.Lookup#findSetter findSetter(C.class,"f",T.class)}</td></tr>
- * <tr><td>4</td><td>REF_putStatic</td><td>C.f:T</td><td>(T)void</td><td>putstatic C.f:T</td>
- * <td>{@linkplain java.lang.invoke.MethodHandles.Lookup#findStaticSetter findStaticSetter(C.class,"f",T.class)}</td></tr>
- * <tr><td>5</td><td>REF_invokeVirtual</td><td>C.m(A*)T</td><td>(C,A*)T</td><td>invokevirtual C.m(A*)T</td>
- * <td>{@linkplain java.lang.invoke.MethodHandles.Lookup#findVirtual findVirtual(C.class,"m",MT)}</td></tr>
- * <tr><td>6</td><td>REF_invokeStatic</td><td>C.m(A*)T</td><td>(C,A*)T</td><td>invokestatic C.m(A*)T</td>
- * <td>{@linkplain java.lang.invoke.MethodHandles.Lookup#findStatic findStatic(C.class,"m",MT)}</td></tr>
- * <tr><td>7</td><td>REF_invokeSpecial</td><td>C.m(A*)T</td><td>(C,A*)T</td><td>invokespecial C.m(A*)T</td>
- * <td>{@linkplain java.lang.invoke.MethodHandles.Lookup#findSpecial findSpecial(C.class,"m",MT,this.class)}</td></tr>
- * <tr><td>8</td><td>REF_newInvokeSpecial</td><td>C.<init>(A*)void</td><td>(A*)C</td><td>new C; dup; invokespecial C.<init>(A*)void</td>
- * <td>{@linkplain java.lang.invoke.MethodHandles.Lookup#findConstructor findConstructor(C.class,MT)}</td></tr>
- * <tr><td>9</td><td>REF_invokeInterface</td><td>C.m(A*)T</td><td>(C,A*)T</td><td>invokeinterface C.m(A*)T</td>
- * <td>{@linkplain java.lang.invoke.MethodHandles.Lookup#findVirtual findVirtual(C.class,"m",MT)}</td></tr>
- * </table>
- * </code>
- * Here, the type {@code C} is taken from the {@code CONSTANT_Class} reference associated
- * with the {@code CONSTANT_NameAndType} descriptor.
- * The field name {@code f} or method name {@code m} is taken from the {@code CONSTANT_NameAndType}
- * as is the result type {@code T} and (in the case of a method or constructor) the argument type sequence
- * {@code A*}.
- * <p>
- * Each method handle constant has an equivalent instruction sequence called its <em>bytecode behavior</em>.
- * In general, creating a method handle constant can be done in exactly the same circumstances that
- * the JVM would successfully resolve the symbolic references in the bytecode behavior.
- * Also, the type of a method handle constant is such that a valid {@code invokeExact} call
- * on the method handle has exactly the same JVM stack effects as the <em>bytecode behavior</em>.
- * Finally, calling a method handle constant on a valid set of arguments has exactly the same effect
- * and returns the same result (if any) as the corresponding <em>bytecode behavior</em>.
- * <p>
- * Each method handle constant also has an equivalent reflective <em>lookup expression</em>,
- * which is a query to a method in {@link java.lang.invoke.MethodHandles.Lookup}.
- * In the example lookup method expression given in the table above, the name {@code MT}
- * stands for a {@code MethodType} built from {@code T} and the sequence of argument types {@code A*}.
- * (Note that the type {@code C} is not prepended to the query type {@code MT} even if the member is non-static.)
- * In the case of {@code findSpecial}, the name {@code this.class} refers to the class containing
- * the bytecodes.
- * <p>
- * The special name {@code <clinit>} is not allowed.
- * The special name {@code <init>} is not allowed except for subtag 8 as shown.
- * <p>
- * The JVM verifier and linker apply the same access checks and restrictions for these references as for the hypothetical
- * bytecode instructions specified in the last column of the table.
- * A method handle constant will successfully resolve to a method handle if the symbolic references
- * of the corresponding bytecode instruction(s) would also resolve successfully.
- * Otherwise, an attempt to resolve the constant will throw equivalent linkage errors.
- * In particular, method handles to
- * private and protected members can be created in exactly those classes for which the corresponding
- * normal accesses are legal.
- * <p>
- * A constant may refer to a method or constructor with the {@code varargs}
- * bit (hexadecimal {@code 0x0080}) set in its modifier bitmask.
- * The method handle constant produced for such a method behaves as if
- * it were created by {@link java.lang.invoke.MethodHandle#asVarargsCollector asVarargsCollector}.
- * In other words, the constant method handle will exhibit variable arity,
- * when invoked via {@code MethodHandle.invoke}.
- * On the other hand, its behavior with respect to {@code invokeExact} will be the same
- * as if the {@code varargs} bit were not set.
- * <p>
- * Although the {@code CONSTANT_MethodHandle} and {@code CONSTANT_MethodType} constant types
- * resolve class names, they do not force class initialization.
- * Method handle constants for subtags {@code REF_getStatic}, {@code REF_putStatic}, and {@code REF_invokeStatic}
- * may force class initialization on their first invocation, just like the corresponding bytecodes.
- * <p>
- * The rules of section 5.4.3 of
- * <cite>The Java™ Virtual Machine Specification</cite>
- * apply to the resolution of {@code CONSTANT_MethodType}, {@code CONSTANT_MethodHandle},
- * and {@code CONSTANT_InvokeDynamic} constants,
- * by the execution of {@code invokedynamic} and {@code ldc} instructions.
- * (Roughly speaking, this means that every use of a constant pool entry
- * must lead to the same outcome.
- * If the resolution succeeds, the same object reference is produced
- * by every subsequent execution of the same instruction.
- * If the resolution of the constant causes an error to occur,
- * the same error will be re-thrown on every subsequent attempt
- * to use this particular constant.)
- * <p>
- * Constants created by the resolution of these constant pool types are not necessarily
- * interned. Except for {@code CONSTANT_Class} and {@code CONSTANT_String} entries,
- * two distinct constant pool entries might not resolve to the same reference
- * even if they contain the same symbolic reference.
- *
- * <h2><a name="bsm"></a>Bootstrap Methods</h2>
* Before the JVM can execute a dynamic call site (an {@code invokedynamic} instruction),
* the call site must first be <em>linked</em>.
* Linking is accomplished by calling a <em>bootstrap method</em>
@@ -234,15 +74,14 @@
* call site execution.
* Linkage does not trigger class initialization.
* <p>
- * Next, the bootstrap method call is started, with at least four values being stacked:
+ * The bootstrap method is invoked on at least three values:
* <ul>
- * <li>a {@code MethodHandle}, the resolved bootstrap method itself </li>
* <li>a {@code MethodHandles.Lookup}, a lookup object on the <em>caller class</em> in which dynamic call site occurs </li>
* <li>a {@code String}, the method name mentioned in the call site </li>
* <li>a {@code MethodType}, the resolved type descriptor of the call </li>
- * <li>optionally, one or more <a href="#args">additional static arguments</a> </li>
+ * <li>optionally, between 1 and 251 additional static arguments taken from the constant pool </li>
* </ul>
- * The method handle is then applied to the other values as if by
+ * Invocation is as if by
* {@link java.lang.invoke.MethodHandle#invoke MethodHandle.invoke}.
* The returned result must be a {@link java.lang.invoke.CallSite CallSite} (or a subclass).
* The type of the call site's target must be exactly equal to the type
@@ -250,38 +89,15 @@
* the bootstrap method.
* The call site then becomes permanently linked to the dynamic call site.
* <p>
- * As long as each bootstrap method can be correctly invoked
- * by <code>MethodHandle.invoke</code>, its detailed type is arbitrary.
- * For example, the first argument could be {@code Object}
- * instead of {@code MethodHandles.Lookup}, and the return type
- * could also be {@code Object} instead of {@code CallSite}.
- * (Note that the types and number of the stacked arguments limit
- * the legal kinds of bootstrap methods to appropriately typed
- * static methods and constructors of {@code CallSite} subclasses.)
- * <p>
- * After resolution, the linkage process may fail in a variety of ways.
- * All failures are reported by a {@link java.lang.BootstrapMethodError BootstrapMethodError},
+ * As documented in the JVM specification, all failures arising from
+ * the linkage of a dynamic call site are reported
+ * by a {@link java.lang.BootstrapMethodError BootstrapMethodError},
* which is thrown as the abnormal termination of the dynamic call
* site execution.
- * The following circumstances will cause this:
- * <ul>
- * <li>the index to the bootstrap method specifier is out of range </li>
- * <li>the bootstrap method cannot be resolved </li>
- * <li>the {@code MethodType} to pass to the bootstrap method cannot be resolved </li>
- * <li>a static argument to the bootstrap method cannot be resolved
- * (i.e., a {@code CONSTANT_Class}, {@code CONSTANT_MethodType},
- * or {@code CONSTANT_MethodHandle} argument cannot be linked) </li>
- * <li>the bootstrap method has the wrong arity,
- * causing {@code MethodHandle.invoke} to throw {@code WrongMethodTypeException} </li>
- * <li>the bootstrap method has a wrong argument or return type </li>
- * <li>the bootstrap method invocation completes abnormally </li>
- * <li>the result from the bootstrap invocation is not a reference to
- * an object of type {@link java.lang.invoke.CallSite CallSite} </li>
- * <li>the target of the {@code CallSite} does not have a target of
- * the expected {@code MethodType} </li>
- * </ul>
+ * If this happens, the same error will the thrown for all subsequent
+ * attempts to execute the dynamic call site.
*
- * <h3><a name="linktime"></a>timing of linkage</h3>
+ * <h3>timing of linkage</h3>
* A dynamic call site is linked just before its first execution.
* The bootstrap method call implementing the linkage occurs within
* a thread that is attempting a first execution.
@@ -306,7 +122,7 @@
* all threads. Any other bootstrap method calls are allowed to complete, but their
* results are ignored, and their dynamic call site invocations proceed with the originally
* chosen target object.
- *
+
* <p style="font-size:smaller;">
* <em>Discussion:</em>
* These rules do not enable the JVM to duplicate dynamic call sites,
@@ -315,64 +131,15 @@
* just before its first invocation.
* There is no way to undo the effect of a completed bootstrap method call.
*
- * <h3><a name="bsmattr">the {@code BootstrapMethods} attribute </h3>
- * Each {@code CONSTANT_InvokeDynamic} entry contains an index which references
- * a bootstrap method specifier; all such specifiers are contained in a separate array.
- * This array is defined by a class attribute named {@code BootstrapMethods}.
- * The body of this attribute consists of a sequence of byte pairs, all interpreted as
- * as 16-bit counts or constant pool indexes, in the {@code u2} format.
- * The attribute body starts with a count of bootstrap method specifiers,
- * which is immediately followed by the sequence of specifiers.
- * <p>
- * Each bootstrap method specifier contains an index to a
- * {@code CONSTANT_MethodHandle} constant, which is the bootstrap
- * method itself.
- * This is followed by a count, and then a sequence (perhaps empty) of
- * indexes to <a href="#args">additional static arguments</a>
- * for the bootstrap method.
- * <p>
- * During class loading, the verifier must check the structure of the
- * {@code BootstrapMethods} attribute. In particular, each constant
- * pool index must be of the correct type. A bootstrap method index
- * must refer to a {@code CONSTANT_MethodHandle} (tag 15).
- * Every other index must refer to a valid operand of an
- * {@code ldc_w} or {@code ldc2_w} instruction (tag 3..8 or 15..16).
- *
- * <h3><a name="args">static arguments to the bootstrap method</h3>
- * An {@code invokedynamic} instruction specifies at least three arguments
- * to pass to its bootstrap method:
- * The caller class (expressed as a {@link java.lang.invoke.MethodHandles.Lookup Lookup object},
- * the name (extracted from the {@code CONSTANT_NameAndType} entry),
- * and the type (also extracted from the {@code CONSTANT_NameAndType} entry).
- * The {@code invokedynamic} instruction may specify additional metadata values
- * to pass to its bootstrap method.
- * Collectively, these values are called <em>static arguments</em> to the
- * {@code invokedynamic} instruction, because they are used once at link
- * time to determine the instruction's behavior on subsequent sets of
- * <em>dynamic arguments</em>.
- * <p>
- * Static arguments are used to communicate application-specific meta-data
- * to the bootstrap method.
- * Drawn from the constant pool, they may include references to classes, method handles,
- * strings, or numeric data that may be relevant to the task of linking that particular call site.
- * <p>
- * Static arguments are specified constant pool indexes stored in the {@code BootstrapMethods} attribute.
- * Before the bootstrap method is invoked, each index is used to compute an {@code Object}
- * reference to the indexed value in the constant pool.
- * The valid constant pool entries are listed in this table:
- * <code>
- * <table border=1 cellpadding=5 summary="Static argument types">
- * <tr><th>entry type</th><th>argument type</th><th>argument value</th></tr>
- * <tr><td>CONSTANT_String</td><td><code>java.lang.String</code></td><td>the indexed string literal</td></tr>
- * <tr><td>CONSTANT_Class</td><td><code>java.lang.Class</code></td><td>the indexed class, resolved</td></tr>
- * <tr><td>CONSTANT_Integer</td><td><code>java.lang.Integer</code></td><td>the indexed int value</td></tr>
- * <tr><td>CONSTANT_Long</td><td><code>java.lang.Long</code></td><td>the indexed long value</td></tr>
- * <tr><td>CONSTANT_Float</td><td><code>java.lang.Float</code></td><td>the indexed float value</td></tr>
- * <tr><td>CONSTANT_Double</td><td><code>java.lang.Double</code></td><td>the indexed double value</td></tr>
- * <tr><td>CONSTANT_MethodHandle</td><td><code>java.lang.invoke.MethodHandle</code></td><td>the indexed method handle constant</td></tr>
- * <tr><td>CONSTANT_MethodType</td><td><code>java.lang.invoke.MethodType</code></td><td>the indexed method type constant</td></tr>
- * </table>
- * </code>
+ * <h3>types of bootstrap methods</h3>
+ * As long as each bootstrap method can be correctly invoked
+ * by {@code MethodHandle.invoke}, its detailed type is arbitrary.
+ * For example, the first argument could be {@code Object}
+ * instead of {@code MethodHandles.Lookup}, and the return type
+ * could also be {@code Object} instead of {@code CallSite}.
+ * (Note that the types and number of the stacked arguments limit
+ * the legal kinds of bootstrap methods to appropriately typed
+ * static methods and constructors of {@code CallSite} subclasses.)
* <p>
* If a given {@code invokedynamic} instruction specifies no static arguments,
* the instruction's bootstrap method will be invoked on three arguments,
@@ -380,7 +147,8 @@
* If the {@code invokedynamic} instruction specifies one or more static arguments,
* those values will be passed as additional arguments to the method handle.
* (Note that because there is a limit of 255 arguments to any method,
- * at most 252 extra arguments can be supplied.)
+ * at most 251 extra arguments can be supplied, since the bootstrap method
+ * handle itself and its first three arguments must also be stacked.)
* The bootstrap method will be invoked as if by either {@code MethodHandle.invoke}
* or {@code invokeWithArguments}. (There is no way to tell the difference.)
* <p>
@@ -390,12 +158,11 @@
* then some or all of the arguments specified here may be collected into a trailing array parameter.
* (This is not a special rule, but rather a useful consequence of the interaction
* between {@code CONSTANT_MethodHandle} constants, the modifier bit for variable arity methods,
- * and the {@code java.lang.invoke.MethodHandle#asVarargsCollector asVarargsCollector} transformation.)
+ * and the {@link java.lang.invoke.MethodHandle#asVarargsCollector asVarargsCollector} transformation.)
* <p>
* Given these rules, here are examples of legal bootstrap method declarations,
* given various numbers {@code N} of extra arguments.
* The first rows (marked {@code *}) will work for any number of extra arguments.
- * <code>
* <table border=1 cellpadding=5 summary="Static argument types">
* <tr><th>N</th><th>sample bootstrap method</th></tr>
* <tr><td>*</td><td><code>CallSite bootstrap(Lookup caller, String name, MethodType type, Object... args)</code></td></tr>
@@ -408,7 +175,6 @@
* <tr><td>2</td><td><code>CallSite bootstrap(Lookup caller, String name, MethodType type, String... args)</code></td></tr>
* <tr><td>2</td><td><code>CallSite bootstrap(Lookup caller, String name, MethodType type, String x, int y)</code></td></tr>
* </table>
- * </code>
* The last example assumes that the extra arguments are of type
* {@code CONSTANT_String} and {@code CONSTANT_Integer}, respectively.
* The second-to-last example assumes that all extra arguments are of type
@@ -431,34 +197,6 @@
* since each call site could be given its own unique bootstrap method.
* Such a practice is likely to produce large class files and constant pools.
*
- * <h2><a name="structs"></a>Structure Summary</h2>
- * <blockquote><pre>// summary of constant and attribute structures
-struct CONSTANT_MethodHandle_info {
- u1 tag = 15;
- u1 reference_kind; // 1..8 (one of REF_invokeVirtual, etc.)
- u2 reference_index; // index to CONSTANT_Fieldref or *Methodref
-}
-struct CONSTANT_MethodType_info {
- u1 tag = 16;
- u2 descriptor_index; // index to CONSTANT_Utf8, as in NameAndType
-}
-struct CONSTANT_InvokeDynamic_info {
- u1 tag = 18;
- u2 bootstrap_method_attr_index; // index into BootstrapMethods_attr
- u2 name_and_type_index; // index to CONSTANT_NameAndType, as in Methodref
-}
-struct BootstrapMethods_attr {
- u2 name; // CONSTANT_Utf8 = "BootstrapMethods"
- u4 size;
- u2 bootstrap_method_count;
- struct bootstrap_method_specifier {
- u2 bootstrap_method_ref; // index to CONSTANT_MethodHandle
- u2 bootstrap_argument_count;
- u2 bootstrap_arguments[bootstrap_argument_count]; // constant pool indexes
- } bootstrap_methods[bootstrap_method_count];
-}
- * </pre></blockquote>
- *
* @author John Rose, JSR 292 EG
* @since 1.7
*/
--- a/jdk/src/share/classes/sun/invoke/util/ValueConversions.java Thu May 26 20:20:03 2011 -0700
+++ b/jdk/src/share/classes/sun/invoke/util/ValueConversions.java Fri May 27 19:03:03 2011 -0700
@@ -198,27 +198,30 @@
return unbox(Wrapper.forPrimitiveType(type), true, false);
}
+ static private final Integer ZERO_INT = 0, ONE_INT = 1;
+
/// Primitive conversions
public static Number primitiveConversion(Wrapper wrap, Object x, boolean cast) {
// Maybe merge this code with Wrapper.convert/cast.
Number res = null;
if (x == null) {
if (!cast) return null;
- x = wrap.zero();
+ return ZERO_INT;
}
if (x instanceof Number) {
res = (Number) x;
} else if (x instanceof Boolean) {
- res = ((boolean)x ? 1 : 0);
+ res = ((boolean)x ? ONE_INT : ZERO_INT);
} else if (x instanceof Character) {
res = (int)(char)x;
} else {
// this will fail with the required ClassCastException:
res = (Number) x;
}
- if (!cast && !wrap.isConvertibleFrom(Wrapper.forWrapperType(x.getClass())))
+ Wrapper xwrap = Wrapper.findWrapperType(x.getClass());
+ if (xwrap == null || !cast && !wrap.isConvertibleFrom(xwrap))
// this will fail with the required ClassCastException:
- res = (Number) wrap.wrapperType().cast(x);
+ return (Number) wrap.wrapperType().cast(x);
return res;
}
--- a/jdk/src/share/classes/sun/invoke/util/VerifyAccess.java Thu May 26 20:20:03 2011 -0700
+++ b/jdk/src/share/classes/sun/invoke/util/VerifyAccess.java Fri May 27 19:03:03 2011 -0700
@@ -154,9 +154,10 @@
* @return whether they are in the same package
*/
public static boolean isSamePackage(Class<?> class1, Class<?> class2) {
+ assert(!class1.isArray() && !class2.isArray());
if (class1 == class2)
return true;
- if (!loadersAreRelated(class1.getClassLoader(), class2.getClassLoader()))
+ if (!loadersAreRelated(class1.getClassLoader(), class2.getClassLoader(), false))
return false;
String name1 = class1.getName(), name2 = class2.getName();
int dot = name1.lastIndexOf('.');
@@ -169,6 +170,16 @@
return true;
}
+ /** Return the package name for this class.
+ */
+ public static String getPackageName(Class<?> cls) {
+ assert(!cls.isArray());
+ String name = cls.getName();
+ int dot = name.lastIndexOf('.');
+ if (dot < 0) return "";
+ return name.substring(0, dot);
+ }
+
/**
* Test if two classes are defined as part of the same package member (top-level class).
* If this is true, they can share private access with each other.
@@ -193,18 +204,33 @@
return pkgmem;
}
- private static boolean loadersAreRelated(ClassLoader loader1, ClassLoader loader2) {
- if (loader1 == loader2 || loader1 == null || loader2 == null) {
+ private static boolean loadersAreRelated(ClassLoader loader1, ClassLoader loader2,
+ boolean loader1MustBeParent) {
+ if (loader1 == loader2 || loader1 == null
+ || (loader2 == null && !loader1MustBeParent)) {
return true;
}
- for (ClassLoader scan1 = loader1;
- scan1 != null; scan1 = scan1.getParent()) {
- if (scan1 == loader2) return true;
- }
for (ClassLoader scan2 = loader2;
scan2 != null; scan2 = scan2.getParent()) {
if (scan2 == loader1) return true;
}
+ if (loader1MustBeParent) return false;
+ // see if loader2 is a parent of loader1:
+ for (ClassLoader scan1 = loader1;
+ scan1 != null; scan1 = scan1.getParent()) {
+ if (scan1 == loader2) return true;
+ }
return false;
}
+
+ /**
+ * Is the class loader of parentClass identical to, or an ancestor of,
+ * the class loader of childClass?
+ * @param parentClass
+ * @param childClass
+ * @return whether parentClass precedes or equals childClass in class loader order
+ */
+ public static boolean classLoaderIsAncestor(Class<?> parentClass, Class<?> childClass) {
+ return loadersAreRelated(parentClass.getClassLoader(), childClass.getClassLoader(), true);
+ }
}
--- a/jdk/src/share/classes/sun/invoke/util/Wrapper.java Thu May 26 20:20:03 2011 -0700
+++ b/jdk/src/share/classes/sun/invoke/util/Wrapper.java Fri May 27 19:03:03 2011 -0700
@@ -135,7 +135,7 @@
* <li>any type converted to {@code void} (i.e., dropping a method call's value)
* <li>boxing conversion followed by widening reference conversion to {@code Object}
* </ul>
- * These are the cases allowed by MethodHandle.asType and convertArguments.
+ * These are the cases allowed by MethodHandle.asType.
*/
public boolean isConvertibleFrom(Wrapper source) {
if (this == source) return true;
--- a/jdk/test/java/lang/invoke/6998541/Test6998541.java Thu May 26 20:20:03 2011 -0700
+++ b/jdk/test/java/lang/invoke/6998541/Test6998541.java Fri May 27 19:03:03 2011 -0700
@@ -164,6 +164,7 @@
private static boolean canDoAsType(Class<?> src, Class<?> dst) {
if (src == dst) return true;
if (dst == void.class) return true;
+ if (src == void.class) return true; // allow void->zero
if (!src.isPrimitive() || !dst.isPrimitive()) return true;
// primitive conversion works for asType only when it's widening
if (src == boolean.class || dst == boolean.class) return false;
@@ -451,7 +452,6 @@
private final static MethodHandle mh_dv = mh(double.class );
private static void void2prim(int i) throws Throwable {
- if (!DO_CASTS) return;
assertEquals( false, (boolean) mh_zv.invokeExact()); // void -> boolean
assertEquals((byte) 0, (byte) mh_bv.invokeExact()); // void -> byte
assertEquals((char) 0, (char) mh_cv.invokeExact()); // void -> char
@@ -463,15 +463,7 @@
}
private static void void2prim_invalid(double x) throws Throwable {
- if (DO_CASTS) return;
- try { assertEquals( false, (boolean) mh_zv.invokeExact()); fail(); } catch (NullPointerException _) {} // void -> boolean
- try { assertEquals((byte) 0, (byte) mh_bv.invokeExact()); fail(); } catch (NullPointerException _) {} // void -> byte
- try { assertEquals((char) 0, (char) mh_cv.invokeExact()); fail(); } catch (NullPointerException _) {} // void -> char
- try { assertEquals((short) 0, (short) mh_sv.invokeExact()); fail(); } catch (NullPointerException _) {} // void -> short
- try { assertEquals( 0, (int) mh_iv.invokeExact()); fail(); } catch (NullPointerException _) {} // void -> int
- try { assertEquals( 0L, (long) mh_jv.invokeExact()); fail(); } catch (NullPointerException _) {} // void -> long
- try { assertEquals( 0.0f, (float) mh_fv.invokeExact()); fail(); } catch (NullPointerException _) {} // void -> float
- try { assertEquals( 0.0d, (double) mh_dv.invokeExact()); fail(); } catch (NullPointerException _) {} // void -> double
+ // no cases
}
private static MethodHandle mh_v(Class arg) { return mh(void.class, arg); }
--- a/jdk/test/java/lang/invoke/InvokeDynamicPrintArgs.java Thu May 26 20:20:03 2011 -0700
+++ b/jdk/test/java/lang/invoke/InvokeDynamicPrintArgs.java Fri May 27 19:03:03 2011 -0700
@@ -106,8 +106,10 @@
"Done printing argument lists."
};
+ private static boolean doPrint = true;
private static void printArgs(Object bsmInfo, Object... args) {
- System.out.println(bsmInfo+Arrays.deepToString(args));
+ String message = bsmInfo+Arrays.deepToString(args);
+ if (doPrint) System.out.println(message);
}
private static MethodHandle MH_printArgs() throws ReflectiveOperationException {
shouldNotCallThis();
@@ -129,11 +131,48 @@
return lookup().findStatic(lookup().lookupClass(), "bsm", MT_bsm());
}
- private static CallSite bsm2(Lookup caller, String name, MethodType type, Object... arg) throws ReflectiveOperationException {
+ /* Example of a constant call site with user-data.
+ * In this case, the user data is exactly the BSM data.
+ * Note that a CCS with user data must use the "hooked" constructor
+ * to bind the CCS itself into the resulting target.
+ * A normal constructor would not allow a circular relation
+ * between the CCS and its target.
+ */
+ public static class PrintingCallSite extends ConstantCallSite {
+ final Lookup caller;
+ final String name;
+ final Object[] staticArgs;
+
+ PrintingCallSite(Lookup caller, String name, MethodType type, Object... staticArgs) throws Throwable {
+ super(type, MH_createTarget());
+ this.caller = caller;
+ this.name = name;
+ this.staticArgs = staticArgs;
+ }
+
+ public MethodHandle createTarget() {
+ try {
+ return lookup().bind(this, "runTarget", genericMethodType(0, true)).asType(type());
+ } catch (ReflectiveOperationException ex) {
+ throw new RuntimeException(ex);
+ }
+ }
+
+ public Object runTarget(Object... dynamicArgs) {
+ List<Object> bsmInfo = new ArrayList<>(Arrays.asList(caller, name, type()));
+ bsmInfo.addAll(Arrays.asList(staticArgs));
+ printArgs(bsmInfo, dynamicArgs);
+ return null;
+ }
+
+ private static MethodHandle MH_createTarget() throws ReflectiveOperationException {
+ shouldNotCallThis();
+ return lookup().findVirtual(lookup().lookupClass(), "createTarget", methodType(MethodHandle.class));
+ }
+ }
+ private static CallSite bsm2(Lookup caller, String name, MethodType type, Object... arg) throws Throwable {
// ignore caller and name, but match the type:
- List<Object> bsmInfo = new ArrayList<>(Arrays.asList(caller, name, type));
- bsmInfo.addAll(Arrays.asList((Object[])arg));
- return new ConstantCallSite(MH_printArgs().bindTo(bsmInfo).asCollector(Object[].class, type.parameterCount()).asType(type));
+ return new PrintingCallSite(caller, name, type, arg);
}
private static MethodType MT_bsm2() {
shouldNotCallThis();
@@ -146,33 +185,33 @@
private static MethodHandle INDY_nothing() throws Throwable {
shouldNotCallThis();
- return ((CallSite) MH_bsm().invokeGeneric(lookup(),
+ return ((CallSite) MH_bsm().invoke(lookup(),
"nothing", methodType(void.class)
)).dynamicInvoker();
}
private static MethodHandle INDY_foo() throws Throwable {
shouldNotCallThis();
- return ((CallSite) MH_bsm().invokeGeneric(lookup(),
+ return ((CallSite) MH_bsm().invoke(lookup(),
"foo", methodType(void.class, String.class)
)).dynamicInvoker();
}
private static MethodHandle INDY_bar() throws Throwable {
shouldNotCallThis();
- return ((CallSite) MH_bsm2().invokeGeneric(lookup(),
+ return ((CallSite) MH_bsm2().invoke(lookup(),
"bar", methodType(void.class, String.class, int.class)
, Void.class, "void type!", 1, 234.5F, 67.5, (long)89
)).dynamicInvoker();
}
private static MethodHandle INDY_bar2() throws Throwable {
shouldNotCallThis();
- return ((CallSite) MH_bsm2().invokeGeneric(lookup(),
+ return ((CallSite) MH_bsm2().invoke(lookup(),
"bar2", methodType(void.class, String.class, int.class)
, Void.class, "void type!", 1, 234.5F, 67.5, (long)89
)).dynamicInvoker();
}
private static MethodHandle INDY_baz() throws Throwable {
shouldNotCallThis();
- return ((CallSite) MH_bsm2().invokeGeneric(lookup(),
+ return ((CallSite) MH_bsm2().invoke(lookup(),
"baz", methodType(void.class, String.class, int.class, double.class)
, 1234.5
)).dynamicInvoker();
--- a/jdk/test/java/lang/invoke/InvokeGenericTest.java Thu May 26 20:20:03 2011 -0700
+++ b/jdk/test/java/lang/invoke/InvokeGenericTest.java Fri May 27 19:03:03 2011 -0700
@@ -314,7 +314,7 @@
ArrayList<Class<?>> argTypes = new ArrayList<Class<?>>(targetType.parameterList());
Collections.fill(argTypes.subList(beg, end), argType);
MethodType ttype2 = MethodType.methodType(targetType.returnType(), argTypes);
- return MethodHandles.convertArguments(target, ttype2);
+ return target.asType(ttype2);
}
// This lookup is good for all members in and under InvokeGenericTest.
@@ -378,7 +378,7 @@
String[] args = { "one", "two" };
MethodHandle mh = callable(Object.class, String.class);
Object res; List resl;
- res = resl = (List) mh.invokeGeneric((String)args[0], (Object)args[1]);
+ res = resl = (List) mh.invoke((String)args[0], (Object)args[1]);
//System.out.println(res);
assertEquals(Arrays.asList(args), res);
}
--- a/jdk/test/java/lang/invoke/JavaDocExamplesTest.java Thu May 26 20:20:03 2011 -0700
+++ b/jdk/test/java/lang/invoke/JavaDocExamplesTest.java Fri May 27 19:03:03 2011 -0700
@@ -34,7 +34,7 @@
$ $JAVA7X_HOME/bin/javac -cp $JUNIT4_JAR -d /tmp/Classes \
$DAVINCI/sources/jdk/test/java/lang/invoke/JavaDocExamplesTest.java
$ $JAVA7X_HOME/bin/java -cp $JUNIT4_JAR:/tmp/Classes \
- -Dtest.java.lang.invoke.JavaDocExamplesTest.verbosity=1 \
+ -DJavaDocExamplesTest.verbosity=1 \
test.java.lang.invoke.JavaDocExamplesTest
----
*/
@@ -45,12 +45,10 @@
import static java.lang.invoke.MethodHandles.*;
import static java.lang.invoke.MethodType.*;
-import java.lang.reflect.*;
import java.util.*;
import org.junit.*;
import static org.junit.Assert.*;
-import static org.junit.Assume.*;
/**
@@ -60,11 +58,29 @@
/** Wrapper for running the JUnit tests in this module.
* Put JUnit on the classpath!
*/
- public static void main(String... ignore) {
- org.junit.runner.JUnitCore.runClasses(JavaDocExamplesTest.class);
+ public static void main(String... ignore) throws Throwable {
+ System.out.println("can run this as:");
+ System.out.println("$ java org.junit.runner.JUnitCore "+JavaDocExamplesTest.class.getName());
+ new JavaDocExamplesTest().run();
+ }
+ public void run() throws Throwable {
+ testFindVirtual();
+ testPermuteArguments();
+ testDropArguments();
+ testFilterArguments();
+ testFoldArguments();
+ testMethodHandlesSummary();
+ testAsSpreader();
+ testAsCollector();
+ testAsVarargsCollector();
+ testAsFixedArity();
+ testAsTypeCornerCases();
+ testMutableCallSite();
}
// How much output?
- static int verbosity = Integer.getInteger("test.java.lang.invoke.JavaDocExamplesTest.verbosity", 0);
+ static final Class<?> THIS_CLASS = JavaDocExamplesTest.class;
+ static int verbosity = Integer.getInteger(THIS_CLASS.getSimpleName()+".verbosity", 0);
+
{}
static final private Lookup LOOKUP = lookup();
@@ -74,17 +90,23 @@
// "hashCode", methodType(int.class));
// form required if ReflectiveOperationException is intercepted:
-static final private MethodHandle CONCAT_2, HASHCODE_2;
+ static final private MethodHandle CONCAT_2, HASHCODE_2, ADD_2, SUB_2;
static {
try {
+ Class<?> THIS_CLASS = LOOKUP.lookupClass();
CONCAT_2 = LOOKUP.findVirtual(String.class,
"concat", methodType(String.class, String.class));
HASHCODE_2 = LOOKUP.findVirtual(Object.class,
"hashCode", methodType(int.class));
+ ADD_2 = LOOKUP.findStatic(THIS_CLASS, "add", methodType(int.class, int.class, int.class));
+ SUB_2 = LOOKUP.findStatic(THIS_CLASS, "sub", methodType(int.class, int.class, int.class));
} catch (ReflectiveOperationException ex) {
throw new RuntimeException(ex);
}
}
+ static int add(int x, int y) { return x + y; }
+ static int sub(int x, int y) { return x - y; }
+
{}
@Test public void testFindVirtual() throws Throwable {
@@ -101,6 +123,39 @@
assertEquals("xy".hashCode(), (int) HASHCODE_3.invokeExact((Object)"xy"));
{}
}
+
+ @Test public void testPermuteArguments() throws Throwable {
+ {{
+{} /// JAVADOC
+MethodType intfn1 = methodType(int.class, int.class);
+MethodType intfn2 = methodType(int.class, int.class, int.class);
+MethodHandle sub = SUB_2;// ... {int x, int y => x-y} ...;
+assert(sub.type().equals(intfn2));
+MethodHandle sub1 = permuteArguments(sub, intfn2, 0, 1);
+MethodHandle rsub = permuteArguments(sub, intfn2, 1, 0);
+assert((int)rsub.invokeExact(1, 100) == 99);
+MethodHandle add = ADD_2;// ... {int x, int y => x+y} ...;
+assert(add.type().equals(intfn2));
+MethodHandle twice = permuteArguments(add, intfn1, 0, 0);
+assert(twice.type().equals(intfn1));
+assert((int)twice.invokeExact(21) == 42);
+ }}
+ {{
+{} /// JAVADOC
+MethodHandle cat = lookup().findVirtual(String.class,
+ "concat", methodType(String.class, String.class));
+assertEquals("xy", (String) cat.invokeExact("x", "y"));
+MethodHandle d0 = dropArguments(cat, 0, String.class);
+assertEquals("yz", (String) d0.invokeExact("x", "y", "z"));
+MethodHandle d1 = dropArguments(cat, 1, String.class);
+assertEquals("xz", (String) d1.invokeExact("x", "y", "z"));
+MethodHandle d2 = dropArguments(cat, 2, String.class);
+assertEquals("xy", (String) d2.invokeExact("x", "y", "z"));
+MethodHandle d12 = dropArguments(cat, 1, int.class, boolean.class);
+assertEquals("xz", (String) d12.invokeExact("x", 12, true, "z"));
+ }}
+ }
+
@Test public void testDropArguments() throws Throwable {
{{
{} /// JAVADOC
@@ -145,6 +200,21 @@
}}
}
+ @Test public void testFoldArguments() throws Throwable {
+ {{
+{} /// JAVADOC
+MethodHandle trace = publicLookup().findVirtual(java.io.PrintStream.class,
+ "println", methodType(void.class, String.class))
+ .bindTo(System.out);
+MethodHandle cat = lookup().findVirtual(String.class,
+ "concat", methodType(String.class, String.class));
+assertEquals("boojum", (String) cat.invokeExact("boo", "jum"));
+MethodHandle catTrace = foldArguments(cat, trace);
+// also prints "boo":
+assertEquals("boojum", (String) catTrace.invokeExact("boo", "jum"));
+ }}
+ }
+
static void assertEquals(Object exp, Object act) {
if (verbosity > 0)
System.out.println("result: "+act);
@@ -162,24 +232,24 @@
mh = lookup.findVirtual(String.class, "replace", mt);
s = (String) mh.invokeExact("daddy",'d','n');
// invokeExact(Ljava/lang/String;CC)Ljava/lang/String;
-assert(s.equals("nanny"));
+assertEquals(s, "nanny");
// weakly typed invocation (using MHs.invoke)
s = (String) mh.invokeWithArguments("sappy", 'p', 'v');
-assert(s.equals("savvy"));
+assertEquals(s, "savvy");
// mt is (Object[])List
mt = MethodType.methodType(java.util.List.class, Object[].class);
mh = lookup.findStatic(java.util.Arrays.class, "asList", mt);
assert(mh.isVarargsCollector());
x = mh.invoke("one", "two");
// invoke(Ljava/lang/String;Ljava/lang/String;)Ljava/lang/Object;
-assert(x.equals(java.util.Arrays.asList("one","two")));
+assertEquals(x, java.util.Arrays.asList("one","two"));
// mt is (Object,Object,Object)Object
mt = MethodType.genericMethodType(3);
mh = mh.asType(mt);
x = mh.invokeExact((Object)1, (Object)2, (Object)3);
// invokeExact(Ljava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
-assert(x.equals(java.util.Arrays.asList(1,2,3)));
-// mt is { => int}
+assertEquals(x, java.util.Arrays.asList(1,2,3));
+// mt is ()int
mt = MethodType.methodType(int.class);
mh = lookup.findVirtual(java.util.List.class, "size", mt);
i = (int) mh.invokeExact(java.util.Arrays.asList(1,2,3));
@@ -193,37 +263,239 @@
}}
}
+ @Test public void testAsSpreader() throws Throwable {
+ {{
+{} /// JAVADOC
+MethodHandle equals = publicLookup()
+ .findVirtual(String.class, "equals", methodType(boolean.class, Object.class));
+assert( (boolean) equals.invokeExact("me", (Object)"me"));
+assert(!(boolean) equals.invokeExact("me", (Object)"thee"));
+// spread both arguments from a 2-array:
+MethodHandle eq2 = equals.asSpreader(Object[].class, 2);
+assert( (boolean) eq2.invokeExact(new Object[]{ "me", "me" }));
+assert(!(boolean) eq2.invokeExact(new Object[]{ "me", "thee" }));
+// spread both arguments from a String array:
+MethodHandle eq2s = equals.asSpreader(String[].class, 2);
+assert( (boolean) eq2s.invokeExact(new String[]{ "me", "me" }));
+assert(!(boolean) eq2s.invokeExact(new String[]{ "me", "thee" }));
+// spread second arguments from a 1-array:
+MethodHandle eq1 = equals.asSpreader(Object[].class, 1);
+assert( (boolean) eq1.invokeExact("me", new Object[]{ "me" }));
+assert(!(boolean) eq1.invokeExact("me", new Object[]{ "thee" }));
+// spread no arguments from a 0-array or null:
+MethodHandle eq0 = equals.asSpreader(Object[].class, 0);
+assert( (boolean) eq0.invokeExact("me", (Object)"me", new Object[0]));
+assert(!(boolean) eq0.invokeExact("me", (Object)"thee", (Object[])null));
+// asSpreader and asCollector are approximate inverses:
+for (int n = 0; n <= 2; n++) {
+ for (Class<?> a : new Class<?>[]{Object[].class, String[].class, CharSequence[].class}) {
+ MethodHandle equals2 = equals.asSpreader(a, n).asCollector(a, n);
+ assert( (boolean) equals2.invokeWithArguments("me", "me"));
+ assert(!(boolean) equals2.invokeWithArguments("me", "thee"));
+ }
+}
+MethodHandle caToString = publicLookup()
+ .findStatic(Arrays.class, "toString", methodType(String.class, char[].class));
+assertEquals("[A, B, C]", (String) caToString.invokeExact("ABC".toCharArray()));
+MethodHandle caString3 = caToString.asCollector(char[].class, 3);
+assertEquals("[A, B, C]", (String) caString3.invokeExact('A', 'B', 'C'));
+MethodHandle caToString2 = caString3.asSpreader(char[].class, 2);
+assertEquals("[A, B, C]", (String) caToString2.invokeExact('A', "BC".toCharArray()));
+ }}
+ }
+
+ @Test public void testAsCollector() throws Throwable {
+ {{
+{} /// JAVADOC
+MethodHandle deepToString = publicLookup()
+ .findStatic(Arrays.class, "deepToString", methodType(String.class, Object[].class));
+assertEquals("[won]", (String) deepToString.invokeExact(new Object[]{"won"}));
+MethodHandle ts1 = deepToString.asCollector(Object[].class, 1);
+assertEquals(methodType(String.class, Object.class), ts1.type());
+//assertEquals("[won]", (String) ts1.invokeExact( new Object[]{"won"})); //FAIL
+assertEquals("[[won]]", (String) ts1.invokeExact((Object) new Object[]{"won"}));
+// arrayType can be a subtype of Object[]
+MethodHandle ts2 = deepToString.asCollector(String[].class, 2);
+assertEquals(methodType(String.class, String.class, String.class), ts2.type());
+assertEquals("[two, too]", (String) ts2.invokeExact("two", "too"));
+MethodHandle ts0 = deepToString.asCollector(Object[].class, 0);
+assertEquals("[]", (String) ts0.invokeExact());
+// collectors can be nested, Lisp-style
+MethodHandle ts22 = deepToString.asCollector(Object[].class, 3).asCollector(String[].class, 2);
+assertEquals("[A, B, [C, D]]", ((String) ts22.invokeExact((Object)'A', (Object)"B", "C", "D")));
+// arrayType can be any primitive array type
+MethodHandle bytesToString = publicLookup()
+ .findStatic(Arrays.class, "toString", methodType(String.class, byte[].class))
+ .asCollector(byte[].class, 3);
+assertEquals("[1, 2, 3]", (String) bytesToString.invokeExact((byte)1, (byte)2, (byte)3));
+MethodHandle longsToString = publicLookup()
+ .findStatic(Arrays.class, "toString", methodType(String.class, long[].class))
+ .asCollector(long[].class, 1);
+assertEquals("[123]", (String) longsToString.invokeExact((long)123));
+ }}
+ }
+
@Test public void testAsVarargsCollector() throws Throwable {
{{
{} /// JAVADOC
+MethodHandle deepToString = publicLookup()
+ .findStatic(Arrays.class, "deepToString", methodType(String.class, Object[].class));
+MethodHandle ts1 = deepToString.asVarargsCollector(Object[].class);
+assertEquals("[won]", (String) ts1.invokeExact( new Object[]{"won"}));
+assertEquals("[won]", (String) ts1.invoke( new Object[]{"won"}));
+assertEquals("[won]", (String) ts1.invoke( "won" ));
+assertEquals("[[won]]", (String) ts1.invoke((Object) new Object[]{"won"}));
+// findStatic of Arrays.asList(...) produces a variable arity method handle:
MethodHandle asList = publicLookup()
- .findStatic(Arrays.class, "asList", methodType(List.class, Object[].class))
- .asVarargsCollector(Object[].class);
+ .findStatic(Arrays.class, "asList", methodType(List.class, Object[].class));
+assertEquals(methodType(List.class, Object[].class), asList.type());
+assert(asList.isVarargsCollector());
assertEquals("[]", asList.invoke().toString());
assertEquals("[1]", asList.invoke(1).toString());
assertEquals("[two, too]", asList.invoke("two", "too").toString());
-Object[] argv = { "three", "thee", "tee" };
+String[] argv = { "three", "thee", "tee" };
assertEquals("[three, thee, tee]", asList.invoke(argv).toString());
+assertEquals("[three, thee, tee]", asList.invoke((Object[])argv).toString());
List ls = (List) asList.invoke((Object)argv);
assertEquals(1, ls.size());
assertEquals("[three, thee, tee]", Arrays.toString((Object[])ls.get(0)));
}}
}
- @Test public void testVarargsCollectorSuppression() throws Throwable {
+ @Test public void testAsFixedArity() throws Throwable {
{{
{} /// JAVADOC
-MethodHandle vamh = publicLookup()
+MethodHandle asListVar = publicLookup()
.findStatic(Arrays.class, "asList", methodType(List.class, Object[].class))
.asVarargsCollector(Object[].class);
-MethodHandle mh = MethodHandles.exactInvoker(vamh.type()).bindTo(vamh);
-assert(vamh.type().equals(mh.type()));
-assertEquals("[1, 2, 3]", vamh.invoke(1,2,3).toString());
-boolean failed = false;
-try { mh.invoke(1,2,3); }
-catch (WrongMethodTypeException ex) { failed = true; }
-assert(failed);
+MethodHandle asListFix = asListVar.asFixedArity();
+assertEquals("[1]", asListVar.invoke(1).toString());
+Exception caught = null;
+try { asListFix.invoke((Object)1); }
+catch (Exception ex) { caught = ex; }
+assert(caught instanceof ClassCastException);
+assertEquals("[two, too]", asListVar.invoke("two", "too").toString());
+try { asListFix.invoke("two", "too"); }
+catch (Exception ex) { caught = ex; }
+assert(caught instanceof WrongMethodTypeException);
+Object[] argv = { "three", "thee", "tee" };
+assertEquals("[three, thee, tee]", asListVar.invoke(argv).toString());
+assertEquals("[three, thee, tee]", asListFix.invoke(argv).toString());
+assertEquals(1, ((List) asListVar.invoke((Object)argv)).size());
+assertEquals("[three, thee, tee]", asListFix.invoke((Object)argv).toString());
+ }}
+ }
+
+ @Test public void testAsTypeCornerCases() throws Throwable {
+ {{
+{} /// JAVADOC
+MethodHandle i2s = publicLookup()
+ .findVirtual(Integer.class, "toString", methodType(String.class));
+i2s = i2s.asType(i2s.type().unwrap());
+MethodHandle l2s = publicLookup()
+ .findVirtual(Long.class, "toString", methodType(String.class));
+l2s = l2s.asType(l2s.type().unwrap());
+
+Exception caught = null;
+try { i2s.asType(methodType(String.class, String.class)); }
+catch (Exception ex) { caught = ex; }
+assert(caught instanceof WrongMethodTypeException);
+
+i2s.asType(methodType(String.class, byte.class));
+i2s.asType(methodType(String.class, Byte.class));
+i2s.asType(methodType(String.class, Character.class));
+i2s.asType(methodType(String.class, Integer.class));
+l2s.asType(methodType(String.class, byte.class));
+l2s.asType(methodType(String.class, Byte.class));
+l2s.asType(methodType(String.class, Character.class));
+l2s.asType(methodType(String.class, Integer.class));
+l2s.asType(methodType(String.class, Long.class));
+
+caught = null;
+try { i2s.asType(methodType(String.class, Long.class)); }
+catch (Exception ex) { caught = ex; }
+assert(caught instanceof WrongMethodTypeException);
+
+MethodHandle i2sGen = i2s.asType(methodType(String.class, Object.class));
+MethodHandle l2sGen = l2s.asType(methodType(String.class, Object.class));
+
+i2sGen.invoke(42); // int -> Integer -> Object -> Integer -> int
+i2sGen.invoke((byte)4); // byte -> Byte -> Object -> Byte -> byte -> int
+l2sGen.invoke(42); // int -> Integer -> Object -> Integer -> int
+l2sGen.invoke((byte)4); // byte -> Byte -> Object -> Byte -> byte -> int
+l2sGen.invoke(0x420000000L);
+
+caught = null;
+try { i2sGen.invoke(0x420000000L); } // long -> Long -> Object -> Integer CCE
+catch (Exception ex) { caught = ex; }
+assert(caught instanceof ClassCastException);
+
+caught = null;
+try { i2sGen.invoke("asdf"); } // String -> Object -> Integer CCE
+catch (Exception ex) { caught = ex; }
+assert(caught instanceof ClassCastException);
{}
}}
}
+
+ @Test public void testMutableCallSite() throws Throwable {
+ {{
+{} /// JAVADOC
+MutableCallSite name = new MutableCallSite(MethodType.methodType(String.class));
+MethodHandle MH_name = name.dynamicInvoker();
+MethodType MT_str1 = MethodType.methodType(String.class);
+MethodHandle MH_upcase = MethodHandles.lookup()
+ .findVirtual(String.class, "toUpperCase", MT_str1);
+MethodHandle worker1 = MethodHandles.filterReturnValue(MH_name, MH_upcase);
+name.setTarget(MethodHandles.constant(String.class, "Rocky"));
+assertEquals("ROCKY", (String) worker1.invokeExact());
+name.setTarget(MethodHandles.constant(String.class, "Fred"));
+assertEquals("FRED", (String) worker1.invokeExact());
+// (mutation can be continued indefinitely)
+/*
+ * </pre></blockquote>
+ * <p>
+ * The same call site may be used in several places at once.
+ * <blockquote><pre>
+ */
+MethodType MT_str2 = MethodType.methodType(String.class, String.class);
+MethodHandle MH_cat = lookup().findVirtual(String.class,
+ "concat", methodType(String.class, String.class));
+MethodHandle MH_dear = MethodHandles.insertArguments(MH_cat, 1, ", dear?");
+MethodHandle worker2 = MethodHandles.filterReturnValue(MH_name, MH_dear);
+assertEquals("Fred, dear?", (String) worker2.invokeExact());
+name.setTarget(MethodHandles.constant(String.class, "Wilma"));
+assertEquals("WILMA", (String) worker1.invokeExact());
+assertEquals("Wilma, dear?", (String) worker2.invokeExact());
+{}
+ }}
+ }
+
+ @Test public void testSwitchPoint() throws Throwable {
+ {{
+{} /// JAVADOC
+MethodHandle MH_strcat = MethodHandles.lookup()
+ .findVirtual(String.class, "concat", MethodType.methodType(String.class, String.class));
+SwitchPoint spt = new SwitchPoint();
+assert(spt.isValid());
+// the following steps may be repeated to re-use the same switch point:
+MethodHandle worker1 = MH_strcat;
+MethodHandle worker2 = MethodHandles.permuteArguments(MH_strcat, MH_strcat.type(), 1, 0);
+MethodHandle worker = spt.guardWithTest(worker1, worker2);
+assertEquals("method", (String) worker.invokeExact("met", "hod"));
+SwitchPoint.invalidateAll(new SwitchPoint[]{ spt });
+assert(!spt.isValid());
+assertEquals("hodmet", (String) worker.invokeExact("met", "hod"));
+{}
+ }}
+ }
+
+ /* ---- TEMPLATE ----
+ @Test public void testFoo() throws Throwable {
+ {{
+{} /// JAVADOC
+{}
+ }}
+ }
+ */
}
--- a/jdk/test/java/lang/invoke/MethodHandlesTest.java Thu May 26 20:20:03 2011 -0700
+++ b/jdk/test/java/lang/invoke/MethodHandlesTest.java Fri May 27 19:03:03 2011 -0700
@@ -100,6 +100,31 @@
// ValueConversions.varargsArray: UnsupportedOperationException: NYI: cannot form a varargs array of length 13
testInsertArguments(0, 0, MAX_ARG_INCREASE+10);
}
+ @Test @Ignore("permuteArguments has trouble with double slots")
+ public void testFail_7() throws Throwable {
+ testPermuteArguments(new Object[]{10, 200L},
+ new Class<?>[]{Integer.class, long.class},
+ new int[]{1,0});
+ testPermuteArguments(new Object[]{10, 200L, 5000L},
+ new Class<?>[]{Integer.class, long.class, long.class},
+ new int[]{2,0,1}); //rot
+ testPermuteArguments(new Object[]{10, 200L, 5000L},
+ new Class<?>[]{Integer.class, long.class, long.class},
+ new int[]{1,2,0}); //rot
+ testPermuteArguments(new Object[]{10, 200L, 5000L},
+ new Class<?>[]{Integer.class, long.class, long.class},
+ new int[]{2,1,0}); //swap
+ testPermuteArguments(new Object[]{10, 200L, 5000L},
+ new Class<?>[]{Integer.class, long.class, long.class},
+ new int[]{0,1,2,2}); //dup
+ testPermuteArguments(new Object[]{10, 200L, 5000L},
+ new Class<?>[]{Integer.class, long.class, long.class},
+ new int[]{2,0,1,2});
+ testPermuteArguments(new Object[]{10, 200L, 5000L},
+ new Class<?>[]{Integer.class, long.class, long.class},
+ new int[]{2,2,0,1});
+ testPermuteArguments(4, Integer.class, 2, long.class, 6);
+ }
static final int MAX_ARG_INCREASE = 3;
public MethodHandlesTest() {
@@ -356,7 +381,7 @@
ArrayList<Class<?>> argTypes = new ArrayList<Class<?>>(targetType.parameterList());
Collections.fill(argTypes.subList(beg, end), argType);
MethodType ttype2 = MethodType.methodType(targetType.returnType(), argTypes);
- return MethodHandles.convertArguments(target, ttype2);
+ return target.asType(ttype2);
}
// This lookup is good for all members in and under MethodHandlesTest.
@@ -1005,13 +1030,13 @@
Class<?> vtype = ftype;
if (ftype != int.class) vtype = Object.class;
if (isGetter) {
- mh = MethodHandles.convertArguments(mh, mh.type().generic()
- .changeReturnType(vtype));
+ mh = mh.asType(mh.type().generic()
+ .changeReturnType(vtype));
} else {
int last = mh.type().parameterCount() - 1;
- mh = MethodHandles.convertArguments(mh, mh.type().generic()
- .changeReturnType(void.class)
- .changeParameterType(last, vtype));
+ mh = mh.asType(mh.type().generic()
+ .changeReturnType(void.class)
+ .changeParameterType(last, vtype));
}
if (f != null && f.getDeclaringClass() == HasFields.class) {
assertEquals(f.get(fields), value); // clean to start with
@@ -1139,7 +1164,7 @@
// FIXME: change Integer.class and (Integer) below to int.class and (int) below.
MethodType gtype = mh.type().generic().changeParameterType(1, Integer.class);
if (testSetter) gtype = gtype.changeReturnType(void.class);
- mh = MethodHandles.convertArguments(mh, gtype);
+ mh = mh.asType(gtype);
}
Object sawValue, expValue;
List<Object> model = array2list(array);
@@ -1233,11 +1258,10 @@
}
void testConvert(MethodHandle id, Class<?> rtype, String name, Class<?>... params) throws Throwable {
- testConvert(true, false, id, rtype, name, params);
- testConvert(true, true, id, rtype, name, params);
+ testConvert(true, id, rtype, name, params);
}
- void testConvert(boolean positive, boolean useAsType,
+ void testConvert(boolean positive,
MethodHandle id, Class<?> rtype, String name, Class<?>... params) throws Throwable {
countTest(positive);
MethodType idType = id.type();
@@ -1265,10 +1289,7 @@
MethodHandle target = null;
RuntimeException error = null;
try {
- if (useAsType)
- target = id.asType(newType);
- else
- target = MethodHandles.convertArguments(id, newType);
+ target = id.asType(newType);
} catch (RuntimeException ex) {
error = ex;
}
@@ -1293,11 +1314,11 @@
MethodType.methodType(Object.class, String.class, Object[].class));
vac0 = vac0.bindTo("vac");
MethodHandle vac = vac0.asVarargsCollector(Object[].class);
- testConvert(true, true, vac.asType(MethodType.genericMethodType(0)), null, "vac");
- testConvert(true, true, vac.asType(MethodType.genericMethodType(0)), null, "vac");
+ testConvert(true, vac.asType(MethodType.genericMethodType(0)), null, "vac");
+ testConvert(true, vac.asType(MethodType.genericMethodType(0)), null, "vac");
for (Class<?> at : new Class[] { Object.class, String.class, Integer.class }) {
- testConvert(true, true, vac.asType(MethodType.genericMethodType(1)), null, "vac", at);
- testConvert(true, true, vac.asType(MethodType.genericMethodType(2)), null, "vac", at, at);
+ testConvert(true, vac.asType(MethodType.genericMethodType(1)), null, "vac", at);
+ testConvert(true, vac.asType(MethodType.genericMethodType(2)), null, "vac", at, at);
}
}
@@ -1306,8 +1327,8 @@
if (CAN_SKIP_WORKING) return;
startTest("permuteArguments");
testPermuteArguments(4, Integer.class, 2, String.class, 0);
- //testPermuteArguments(6, Integer.class, 0, null, 30);
- //testPermuteArguments(4, Integer.class, 1, int.class, 6);
+ testPermuteArguments(6, Integer.class, 0, null, 30);
+ //testPermuteArguments(4, Integer.class, 2, long.class, 6); // FIXME Fail_7
}
public void testPermuteArguments(int max, Class<?> type1, int t2c, Class<?> type2, int dilution) throws Throwable {
if (verbosity >= 2)
@@ -1421,8 +1442,9 @@
}
MethodType inType = MethodType.methodType(Object.class, types);
MethodType outType = MethodType.methodType(Object.class, permTypes);
- MethodHandle target = MethodHandles.convertArguments(varargsList(outargs), outType);
+ MethodHandle target = varargsList(outargs).asType(outType);
MethodHandle newTarget = MethodHandles.permuteArguments(target, inType, reorder);
+ if (verbosity >= 5) System.out.println("newTarget = "+newTarget);
Object result = newTarget.invokeWithArguments(args);
Object expected = Arrays.asList(permArgs);
if (!expected.equals(result)) {
@@ -1666,7 +1688,7 @@
countTest();
MethodHandle target = varargsList(nargs);
MethodHandle filter = varargsList(1);
- filter = MethodHandles.convertArguments(filter, filter.type().generic());
+ filter = filter.asType(filter.type().generic());
Object[] argsToPass = randomArgs(nargs, Object.class);
if (verbosity >= 3)
System.out.println("filter "+target+" at "+pos+" with "+filter);
@@ -1807,7 +1829,7 @@
// generic invoker
countTest();
inv = MethodHandles.invoker(type);
- if (nargs <= 3) {
+ if (nargs <= 3 && type == type.generic()) {
calledLog.clear();
switch (nargs) {
case 0:
@@ -1833,10 +1855,16 @@
// varargs invoker #0
calledLog.clear();
inv = MethodHandles.spreadInvoker(type, 0);
- result = inv.invokeExact(target, args);
+ if (type.returnType() == Object.class) {
+ result = inv.invokeExact(target, args);
+ } else if (type.returnType() == void.class) {
+ result = null; inv.invokeExact(target, args);
+ } else {
+ result = inv.invokeWithArguments(target, (Object) args);
+ }
if (testRetCode) assertEquals(code, result);
assertCalled("invokee", args);
- if (nargs >= 1) {
+ if (nargs >= 1 && type == type.generic()) {
// varargs invoker #1
calledLog.clear();
inv = MethodHandles.spreadInvoker(type, 1);
@@ -1844,7 +1872,7 @@
if (testRetCode) assertEquals(code, result);
assertCalled("invokee", args);
}
- if (nargs >= 2) {
+ if (nargs >= 2 && type == type.generic()) {
// varargs invoker #2
calledLog.clear();
inv = MethodHandles.spreadInvoker(type, 2);
@@ -1852,7 +1880,7 @@
if (testRetCode) assertEquals(code, result);
assertCalled("invokee", args);
}
- if (nargs >= 3) {
+ if (nargs >= 3 && type == type.generic()) {
// varargs invoker #3
calledLog.clear();
inv = MethodHandles.spreadInvoker(type, 3);
@@ -1865,6 +1893,10 @@
countTest();
calledLog.clear();
inv = MethodHandles.spreadInvoker(type, k);
+ MethodType expType = (type.dropParameterTypes(k, nargs)
+ .appendParameterTypes(Object[].class)
+ .insertParameterTypes(0, MethodHandle.class));
+ assertEquals(expType, inv.type());
List<Object> targetPlusVarArgs = new ArrayList<Object>(targetPlusArgs);
List<Object> tailList = targetPlusVarArgs.subList(1+k, 1+nargs);
Object[] tail = tailList.toArray();
@@ -2045,7 +2077,7 @@
//System.out.println("throwing with "+target+" : "+thrown);
MethodType expectedType = MethodType.methodType(returnType, exType);
assertEquals(expectedType, target.type());
- target = MethodHandles.convertArguments(target, target.type().generic());
+ target = target.asType(target.type().generic());
Throwable caught = null;
try {
Object res = target.invokeExact((Object) thrown);
@@ -2117,12 +2149,12 @@
if (mode.endsWith("/return")) {
if (mode.equals("unbox/return")) {
// fail on return to ((Integer)surprise).intValue
- surprise = MethodHandles.convertArguments(surprise, MethodType.methodType(int.class, Object.class));
- identity = MethodHandles.convertArguments(identity, MethodType.methodType(int.class, Object.class));
+ surprise = surprise.asType(MethodType.methodType(int.class, Object.class));
+ identity = identity.asType(MethodType.methodType(int.class, Object.class));
} else if (mode.equals("cast/return")) {
// fail on return to (Integer)surprise
- surprise = MethodHandles.convertArguments(surprise, MethodType.methodType(Integer.class, Object.class));
- identity = MethodHandles.convertArguments(identity, MethodType.methodType(Integer.class, Object.class));
+ surprise = surprise.asType(MethodType.methodType(Integer.class, Object.class));
+ identity = identity.asType(MethodType.methodType(Integer.class, Object.class));
}
} else if (mode.endsWith("/argument")) {
MethodHandle callee = null;
@@ -2134,14 +2166,14 @@
callee = Surprise.BOX_IDENTITY;
}
if (callee != null) {
- callee = MethodHandles.convertArguments(callee, MethodType.genericMethodType(1));
+ callee = callee.asType(MethodType.genericMethodType(1));
surprise = MethodHandles.filterArguments(callee, 0, surprise);
identity = MethodHandles.filterArguments(callee, 0, identity);
}
}
assertNotSame(mode, surprise, surprise0);
- identity = MethodHandles.convertArguments(identity, MethodType.genericMethodType(1));
- surprise = MethodHandles.convertArguments(surprise, MethodType.genericMethodType(1));
+ identity = identity.asType(MethodType.genericMethodType(1));
+ surprise = surprise.asType(MethodType.genericMethodType(1));
Object x = 42;
for (int i = 0; i < okCount; i++) {
Object y = identity.invokeExact(x);
@@ -2230,14 +2262,14 @@
{
MethodType mt = MethodType.methodType(void.class);
MethodHandle mh = lookup.findStatic(MethodHandlesTest.class, "runForRunnable", mt);
- Runnable proxy = MethodHandles.asInstance(mh, Runnable.class);
+ Runnable proxy = MethodHandleProxies.asInterfaceInstance(Runnable.class, mh);
proxy.run();
assertCalled("runForRunnable");
}
{
MethodType mt = MethodType.methodType(Object.class, Fooable.class, Object.class);
MethodHandle mh = lookup.findStatic(MethodHandlesTest.class, "fooForFooable", mt);
- Fooable proxy = MethodHandles.asInstance(mh, Fooable.class);
+ Fooable proxy = MethodHandleProxies.asInterfaceInstance(Fooable.class, mh);
Object[] args = randomArgs(mt.parameterArray());
Object result = proxy.foo((Fooable) args[0], args[1]);
assertCalled("fooForFooable", args);
@@ -2251,7 +2283,7 @@
}) {
MethodHandle mh = MethodHandles.throwException(void.class, Throwable.class);
mh = MethodHandles.insertArguments(mh, 0, ex);
- WillThrow proxy = MethodHandles.asInstance(mh, WillThrow.class);
+ WillThrow proxy = MethodHandleProxies.asInterfaceInstance(WillThrow.class, mh);
try {
proxy.willThrow();
System.out.println("Failed to throw: "+ex);
@@ -2279,7 +2311,7 @@
CharSequence.class,
Example.class }) {
try {
- MethodHandles.asInstance(varargsArray(0), nonSAM);
+ MethodHandleProxies.asInterfaceInstance(nonSAM, varargsArray(0));
System.out.println("Failed to throw");
assertTrue(false);
} catch (IllegalArgumentException ex) {
--- a/jdk/test/java/lang/invoke/indify/Indify.java Thu May 26 20:20:03 2011 -0700
+++ b/jdk/test/java/lang/invoke/indify/Indify.java Fri May 27 19:03:03 2011 -0700
@@ -524,6 +524,8 @@
if (verifySpecifierCount >= 0) {
List<Object[]> specs = bootstrapMethodSpecifiers(false);
int specsLen = (specs == null ? 0 : specs.size());
+ // Pass by specsLen == 0, to help with associated (inner) classes.
+ if (specsLen == 0) specsLen = verifySpecifierCount;
if (specsLen != verifySpecifierCount) {
throw new IllegalArgumentException("BootstrapMethods length is "+specsLen+" but should be "+verifySpecifierCount);
}