--- a/src/java.base/share/classes/java/lang/invoke/BootstrapMethodInvoker.java Thu Feb 22 11:52:01 2018 +0530
+++ b/src/java.base/share/classes/java/lang/invoke/BootstrapMethodInvoker.java Thu Feb 22 11:16:43 2018 +0100
@@ -37,6 +37,7 @@
import static java.lang.invoke.MethodHandles.Lookup.IMPL_LOOKUP;
final class BootstrapMethodInvoker {
+
/**
* Factored code for invoking a bootstrap method for invokedynamic
* or a dynamic constant.
@@ -76,14 +77,30 @@
bootstrapMethod = null;
}
try {
+ // As an optimization we special case various known BSMs,
+ // such as LambdaMetafactory::metafactory and
+ // StringConcatFactory::makeConcatWithConstants.
+ //
+ // By providing static type information or even invoking
+ // exactly, we avoid emitting code to perform runtime
+ // checking.
info = maybeReBox(info);
if (info == null) {
// VM is allowed to pass up a null meaning no BSM args
- result = bootstrapMethod.invoke(caller, name, type);
+ result = invoke(bootstrapMethod, caller, name, type);
}
else if (!info.getClass().isArray()) {
// VM is allowed to pass up a single BSM arg directly
- result = bootstrapMethod.invoke(caller, name, type, info);
+
+ // Call to StringConcatFactory::makeConcatWithConstants
+ // with empty constant arguments?
+ if (isStringConcatFactoryBSM(bootstrapMethod.type())) {
+ result = (CallSite)bootstrapMethod
+ .invokeExact(caller, name, (MethodType)type,
+ (String)info, new Object[0]);
+ } else {
+ result = invoke(bootstrapMethod, caller, name, type, info);
+ }
}
else if (info.getClass() == int[].class) {
// VM is allowed to pass up a pair {argc, index}
@@ -103,67 +120,52 @@
// VM is allowed to pass up a full array of resolved BSM args
Object[] argv = (Object[]) info;
maybeReBoxElements(argv);
- switch (argv.length) {
- case 0:
- result = bootstrapMethod.invoke(caller, name, type);
- break;
- case 1:
- result = bootstrapMethod.invoke(caller, name, type,
- argv[0]);
- break;
- case 2:
- result = bootstrapMethod.invoke(caller, name, type,
- argv[0], argv[1]);
- break;
- case 3:
- // Special case the LambdaMetafactory::metafactory BSM
- //
- // By invoking exactly, we can avoid generating a number of
- // classes on first (and subsequent) lambda initialization,
- // most of which won't be shared with other invoke uses.
- MethodType bsmType = bootstrapMethod.type();
- if (isLambdaMetafactoryIndyBSM(bsmType)) {
- result = (CallSite)bootstrapMethod
- .invokeExact(caller, name, (MethodType)type, (MethodType)argv[0],
- (MethodHandle)argv[1], (MethodType)argv[2]);
- } else if (isLambdaMetafactoryCondyBSM(bsmType)) {
- result = bootstrapMethod
- .invokeExact(caller, name, (Class<?>)type, (MethodType)argv[0],
- (MethodHandle)argv[1], (MethodType)argv[2]);
- } else {
- result = bootstrapMethod.invoke(caller, name, type,
- argv[0], argv[1], argv[2]);
- }
- break;
- case 4:
- result = bootstrapMethod.invoke(caller, name, type,
- argv[0], argv[1], argv[2], argv[3]);
- break;
- case 5:
- result = bootstrapMethod.invoke(caller, name, type,
- argv[0], argv[1], argv[2], argv[3], argv[4]);
- break;
- case 6:
- result = bootstrapMethod.invoke(caller, name, type,
- argv[0], argv[1], argv[2], argv[3], argv[4], argv[5]);
- break;
- default:
- final int NON_SPREAD_ARG_COUNT = 3; // (caller, name, type)
- final int MAX_SAFE_SIZE = MethodType.MAX_MH_ARITY / 2 - NON_SPREAD_ARG_COUNT;
- if (argv.length >= MAX_SAFE_SIZE) {
- // to be on the safe side, use invokeWithArguments which handles jumbo lists
- Object[] newargv = new Object[NON_SPREAD_ARG_COUNT + argv.length];
- newargv[0] = caller;
- newargv[1] = name;
- newargv[2] = type;
- System.arraycopy(argv, 0, newargv, NON_SPREAD_ARG_COUNT, argv.length);
- result = bootstrapMethod.invokeWithArguments(newargv);
+
+ MethodType bsmType = bootstrapMethod.type();
+ if (isLambdaMetafactoryIndyBSM(bsmType) && argv.length == 3) {
+ result = (CallSite)bootstrapMethod
+ .invokeExact(caller, name, (MethodType)type, (MethodType)argv[0],
+ (MethodHandle)argv[1], (MethodType)argv[2]);
+ } else if (isLambdaMetafactoryCondyBSM(bsmType) && argv.length == 3) {
+ result = bootstrapMethod
+ .invokeExact(caller, name, (Class<?>)type, (MethodType)argv[0],
+ (MethodHandle)argv[1], (MethodType)argv[2]);
+ } else if (isStringConcatFactoryBSM(bsmType) && argv.length >= 1) {
+ String recipe = (String)argv[0];
+ Object[] shiftedArgs = Arrays.copyOfRange(argv, 1, argv.length);
+ result = (CallSite)bootstrapMethod.invokeExact(caller, name, (MethodType)type, recipe, shiftedArgs);
+ } else {
+ switch (argv.length) {
+ case 0:
+ result = invoke(bootstrapMethod, caller, name, type);
+ break;
+ case 1:
+ result = invoke(bootstrapMethod, caller, name, type,
+ argv[0]);
break;
- }
- MethodType invocationType = MethodType.genericMethodType(NON_SPREAD_ARG_COUNT + argv.length);
- MethodHandle typedBSM = bootstrapMethod.asType(invocationType);
- MethodHandle spreader = invocationType.invokers().spreadInvoker(NON_SPREAD_ARG_COUNT);
- result = spreader.invokeExact(typedBSM, (Object) caller, (Object) name, type, argv);
+ case 2:
+ result = invoke(bootstrapMethod, caller, name, type,
+ argv[0], argv[1]);
+ break;
+ case 3:
+ result = invoke(bootstrapMethod, caller, name, type,
+ argv[0], argv[1], argv[2]);
+ break;
+ case 4:
+ result = invoke(bootstrapMethod, caller, name, type,
+ argv[0], argv[1], argv[2], argv[3]);
+ break;
+ case 5:
+ result = invoke(bootstrapMethod, caller, name, type,
+ argv[0], argv[1], argv[2], argv[3], argv[4]);
+ break;
+ case 6:
+ result = invoke(bootstrapMethod, caller, name, type,
+ argv[0], argv[1], argv[2], argv[3], argv[4], argv[5]);
+ break;
+ default:
+ result = invokeWithManyArguments(bootstrapMethod, caller, name, type, argv);
+ }
}
}
if (resultType.isPrimitive()) {
@@ -191,12 +193,114 @@
}
}
+ // If we don't provide static type information for type, we'll generate runtime
+ // checks. Let's try not to...
+
+ private static Object invoke(MethodHandle bootstrapMethod, Lookup caller,
+ String name, Object type) throws Throwable {
+ if (type instanceof Class) {
+ return bootstrapMethod.invoke(caller, name, (Class<?>)type);
+ } else {
+ return bootstrapMethod.invoke(caller, name, (MethodType)type);
+ }
+ }
+
+ private static Object invoke(MethodHandle bootstrapMethod, Lookup caller,
+ String name, Object type, Object arg0) throws Throwable {
+ if (type instanceof Class) {
+ return bootstrapMethod.invoke(caller, name, (Class<?>)type, arg0);
+ } else {
+ return bootstrapMethod.invoke(caller, name, (MethodType)type, arg0);
+ }
+ }
+
+ private static Object invoke(MethodHandle bootstrapMethod, Lookup caller, String name,
+ Object type, Object arg0, Object arg1) throws Throwable {
+ if (type instanceof Class) {
+ return bootstrapMethod.invoke(caller, name, (Class<?>)type, arg0, arg1);
+ } else {
+ return bootstrapMethod.invoke(caller, name, (MethodType)type, arg0, arg1);
+ }
+ }
+
+ private static Object invoke(MethodHandle bootstrapMethod, Lookup caller, String name,
+ Object type, Object arg0, Object arg1,
+ Object arg2) throws Throwable {
+ if (type instanceof Class) {
+ return bootstrapMethod.invoke(caller, name, (Class<?>)type, arg0, arg1, arg2);
+ } else {
+ return bootstrapMethod.invoke(caller, name, (MethodType)type, arg0, arg1, arg2);
+ }
+ }
+
+ private static Object invoke(MethodHandle bootstrapMethod, Lookup caller, String name,
+ Object type, Object arg0, Object arg1,
+ Object arg2, Object arg3) throws Throwable {
+ if (type instanceof Class) {
+ return bootstrapMethod.invoke(caller, name, (Class<?>)type, arg0, arg1, arg2, arg3);
+ } else {
+ return bootstrapMethod.invoke(caller, name, (MethodType)type, arg0, arg1, arg2, arg3);
+ }
+ }
+
+ private static Object invoke(MethodHandle bootstrapMethod, Lookup caller,
+ String name, Object type, Object arg0, Object arg1,
+ Object arg2, Object arg3, Object arg4) throws Throwable {
+ if (type instanceof Class) {
+ return bootstrapMethod.invoke(caller, name, (Class<?>)type, arg0, arg1, arg2, arg3, arg4);
+ } else {
+ return bootstrapMethod.invoke(caller, name, (MethodType)type, arg0, arg1, arg2, arg3, arg4);
+ }
+ }
+
+ private static Object invoke(MethodHandle bootstrapMethod, Lookup caller,
+ String name, Object type, Object arg0, Object arg1,
+ Object arg2, Object arg3, Object arg4, Object arg5) throws Throwable {
+ if (type instanceof Class) {
+ return bootstrapMethod.invoke(caller, name, (Class<?>)type, arg0, arg1, arg2, arg3, arg4, arg5);
+ } else {
+ return bootstrapMethod.invoke(caller, name, (MethodType)type, arg0, arg1, arg2, arg3, arg4, arg5);
+ }
+ }
+
+ private static Object invokeWithManyArguments(MethodHandle bootstrapMethod, Lookup caller,
+ String name, Object type, Object[] argv) throws Throwable {
+ final int NON_SPREAD_ARG_COUNT = 3; // (caller, name, type)
+ final int MAX_SAFE_SIZE = MethodType.MAX_MH_ARITY / 2 - NON_SPREAD_ARG_COUNT;
+ if (argv.length >= MAX_SAFE_SIZE) {
+ // to be on the safe side, use invokeWithArguments which handles jumbo lists
+ Object[] newargv = new Object[NON_SPREAD_ARG_COUNT + argv.length];
+ newargv[0] = caller;
+ newargv[1] = name;
+ newargv[2] = type;
+ System.arraycopy(argv, 0, newargv, NON_SPREAD_ARG_COUNT, argv.length);
+ return bootstrapMethod.invokeWithArguments(newargv);
+ } else {
+ MethodType invocationType = MethodType.genericMethodType(NON_SPREAD_ARG_COUNT + argv.length);
+ MethodHandle typedBSM = bootstrapMethod.asType(invocationType);
+ MethodHandle spreader = invocationType.invokers().spreadInvoker(NON_SPREAD_ARG_COUNT);
+ return spreader.invokeExact(typedBSM, (Object) caller, (Object) name, type, argv);
+ }
+ }
+
private static final MethodType LMF_INDY_MT = MethodType.methodType(CallSite.class,
Lookup.class, String.class, MethodType.class, MethodType.class, MethodHandle.class, MethodType.class);
private static final MethodType LMF_CONDY_MT = MethodType.methodType(Object.class,
Lookup.class, String.class, Class.class, MethodType.class, MethodHandle.class, MethodType.class);
+ private static final MethodType SCF_MT = MethodType.methodType(CallSite.class,
+ Lookup.class, String.class, MethodType.class, String.class, Object[].class);
+
+ /**
+ * @return true iff the BSM method type exactly matches
+ * {@see java.lang.invoke.StringConcatFactory#makeConcatWithConstants(MethodHandles.Lookup,
+ * String,MethodType,String,Object...))}
+ */
+ private static boolean isStringConcatFactoryBSM(MethodType bsmType) {
+ return bsmType == SCF_MT;
+ }
+
/**
* @return true iff the BSM method type exactly matches
* {@see java.lang.invoke.LambdaMetafactory#metafactory(