--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/share/classes/java/lang/invoke/MethodTypeForm.java Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,431 @@
+/*
+ * Copyright (c) 2008, 2016, 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 jdk.internal.vm.annotation.Stable;
+import sun.invoke.util.Wrapper;
+
+import java.lang.ref.SoftReference;
+
+import static java.lang.invoke.MethodHandleStatics.newIllegalArgumentException;
+
+/**
+ * Shared information for a group of method types, which differ
+ * only by reference types, and therefore share a common erasure
+ * and wrapping.
+ * <p>
+ * For an empirical discussion of the structure of method types,
+ * see <a href="http://groups.google.com/group/jvm-languages/browse_thread/thread/ac9308ae74da9b7e/">
+ * the thread "Avoiding Boxing" on jvm-languages</a>.
+ * There are approximately 2000 distinct erased method types in the JDK.
+ * There are a little over 10 times that number of unerased types.
+ * No more than half of these are likely to be loaded at once.
+ * @author John Rose
+ */
+final class MethodTypeForm {
+ final int[] argToSlotTable, slotToArgTable;
+ final long argCounts; // packed slot & value counts
+ final long primCounts; // packed prim & double counts
+ final MethodType erasedType; // the canonical erasure
+ final MethodType basicType; // the canonical erasure, with primitives simplified
+
+ // Cached adapter information:
+ @Stable final SoftReference<MethodHandle>[] methodHandles;
+ // Indexes into methodHandles:
+ static final int
+ MH_BASIC_INV = 0, // cached instance of MH.invokeBasic
+ MH_NF_INV = 1, // cached helper for LF.NamedFunction
+ MH_UNINIT_CS = 2, // uninitialized call site
+ MH_LIMIT = 3;
+
+ // Cached lambda form information, for basic types only:
+ final @Stable SoftReference<LambdaForm>[] lambdaForms;
+ // Indexes into lambdaForms:
+ static final int
+ LF_INVVIRTUAL = 0, // DMH invokeVirtual
+ LF_INVSTATIC = 1,
+ LF_INVSPECIAL = 2,
+ LF_NEWINVSPECIAL = 3,
+ LF_INVINTERFACE = 4,
+ LF_INVSTATIC_INIT = 5, // DMH invokeStatic with <clinit> barrier
+ LF_INTERPRET = 6, // LF interpreter
+ LF_REBIND = 7, // BoundMethodHandle
+ LF_DELEGATE = 8, // DelegatingMethodHandle
+ LF_DELEGATE_BLOCK_INLINING = 9, // Counting DelegatingMethodHandle w/ @DontInline
+ LF_EX_LINKER = 10, // invokeExact_MT (for invokehandle)
+ LF_EX_INVOKER = 11, // MHs.invokeExact
+ LF_GEN_LINKER = 12, // generic invoke_MT (for invokehandle)
+ LF_GEN_INVOKER = 13, // generic MHs.invoke
+ LF_CS_LINKER = 14, // linkToCallSite_CS
+ LF_MH_LINKER = 15, // linkToCallSite_MH
+ LF_GWC = 16, // guardWithCatch (catchException)
+ LF_GWT = 17, // guardWithTest
+ LF_TF = 18, // tryFinally
+ LF_LOOP = 19, // loop
+ LF_LIMIT = 20;
+
+ /** Return the type corresponding uniquely (1-1) to this MT-form.
+ * It might have any primitive returns or arguments, but will have no references except Object.
+ */
+ public MethodType erasedType() {
+ return erasedType;
+ }
+
+ /** Return the basic type derived from the erased type of this MT-form.
+ * A basic type is erased (all references Object) and also has all primitive
+ * types (except int, long, float, double, void) normalized to int.
+ * Such basic types correspond to low-level JVM calling sequences.
+ */
+ public MethodType basicType() {
+ return basicType;
+ }
+
+ private boolean assertIsBasicType() {
+ // primitives must be flattened also
+ assert(erasedType == basicType)
+ : "erasedType: " + erasedType + " != basicType: " + basicType;
+ return true;
+ }
+
+ public MethodHandle cachedMethodHandle(int which) {
+ assert(assertIsBasicType());
+ SoftReference<MethodHandle> entry = methodHandles[which];
+ return (entry != null) ? entry.get() : null;
+ }
+
+ public synchronized MethodHandle setCachedMethodHandle(int which, MethodHandle mh) {
+ // Simulate a CAS, to avoid racy duplication of results.
+ SoftReference<MethodHandle> entry = methodHandles[which];
+ if (entry != null) {
+ MethodHandle prev = entry.get();
+ if (prev != null) {
+ return prev;
+ }
+ }
+ methodHandles[which] = new SoftReference<>(mh);
+ return mh;
+ }
+
+ public LambdaForm cachedLambdaForm(int which) {
+ assert(assertIsBasicType());
+ SoftReference<LambdaForm> entry = lambdaForms[which];
+ return (entry != null) ? entry.get() : null;
+ }
+
+ public synchronized LambdaForm setCachedLambdaForm(int which, LambdaForm form) {
+ // Simulate a CAS, to avoid racy duplication of results.
+ SoftReference<LambdaForm> entry = lambdaForms[which];
+ if (entry != null) {
+ LambdaForm prev = entry.get();
+ if (prev != null) {
+ return prev;
+ }
+ }
+ lambdaForms[which] = new SoftReference<>(form);
+ return form;
+ }
+
+ /**
+ * Build an MTF for a given type, which must have all references erased to Object.
+ * This MTF will stand for that type and all un-erased variations.
+ * Eagerly compute some basic properties of the type, common to all variations.
+ */
+ @SuppressWarnings({"rawtypes", "unchecked"})
+ protected MethodTypeForm(MethodType erasedType) {
+ this.erasedType = erasedType;
+
+ Class<?>[] ptypes = erasedType.ptypes();
+ int ptypeCount = ptypes.length;
+ int pslotCount = ptypeCount; // temp. estimate
+ int rtypeCount = 1; // temp. estimate
+ int rslotCount = 1; // temp. estimate
+
+ int[] argToSlotTab = null, slotToArgTab = null;
+
+ // Walk the argument types, looking for primitives.
+ int pac = 0, lac = 0, prc = 0, lrc = 0;
+ Class<?>[] epts = ptypes;
+ Class<?>[] bpts = epts;
+ for (int i = 0; i < epts.length; i++) {
+ Class<?> pt = epts[i];
+ if (pt != Object.class) {
+ ++pac;
+ Wrapper w = Wrapper.forPrimitiveType(pt);
+ if (w.isDoubleWord()) ++lac;
+ if (w.isSubwordOrInt() && pt != int.class) {
+ if (bpts == epts)
+ bpts = bpts.clone();
+ bpts[i] = int.class;
+ }
+ }
+ }
+ pslotCount += lac; // #slots = #args + #longs
+ Class<?> rt = erasedType.returnType();
+ Class<?> bt = rt;
+ if (rt != Object.class) {
+ ++prc; // even void.class counts as a prim here
+ Wrapper w = Wrapper.forPrimitiveType(rt);
+ if (w.isDoubleWord()) ++lrc;
+ if (w.isSubwordOrInt() && rt != int.class)
+ bt = int.class;
+ // adjust #slots, #args
+ if (rt == void.class)
+ rtypeCount = rslotCount = 0;
+ else
+ rslotCount += lrc;
+ }
+ if (epts == bpts && bt == rt) {
+ this.basicType = erasedType;
+ } else {
+ this.basicType = MethodType.makeImpl(bt, bpts, true);
+ // fill in rest of data from the basic type:
+ MethodTypeForm that = this.basicType.form();
+ assert(this != that);
+ this.primCounts = that.primCounts;
+ this.argCounts = that.argCounts;
+ this.argToSlotTable = that.argToSlotTable;
+ this.slotToArgTable = that.slotToArgTable;
+ this.methodHandles = null;
+ this.lambdaForms = null;
+ return;
+ }
+ if (lac != 0) {
+ int slot = ptypeCount + lac;
+ slotToArgTab = new int[slot+1];
+ argToSlotTab = new int[1+ptypeCount];
+ argToSlotTab[0] = slot; // argument "-1" is past end of slots
+ for (int i = 0; i < epts.length; i++) {
+ Class<?> pt = epts[i];
+ Wrapper w = Wrapper.forBasicType(pt);
+ if (w.isDoubleWord()) --slot;
+ --slot;
+ slotToArgTab[slot] = i+1; // "+1" see argSlotToParameter note
+ argToSlotTab[1+i] = slot;
+ }
+ assert(slot == 0); // filled the table
+ } else if (pac != 0) {
+ // have primitives but no long primitives; share slot counts with generic
+ assert(ptypeCount == pslotCount);
+ MethodTypeForm that = MethodType.genericMethodType(ptypeCount).form();
+ assert(this != that);
+ slotToArgTab = that.slotToArgTable;
+ argToSlotTab = that.argToSlotTable;
+ } else {
+ int slot = ptypeCount; // first arg is deepest in stack
+ slotToArgTab = new int[slot+1];
+ argToSlotTab = new int[1+ptypeCount];
+ argToSlotTab[0] = slot; // argument "-1" is past end of slots
+ for (int i = 0; i < ptypeCount; i++) {
+ --slot;
+ slotToArgTab[slot] = i+1; // "+1" see argSlotToParameter note
+ argToSlotTab[1+i] = slot;
+ }
+ }
+ this.primCounts = pack(lrc, prc, lac, pac);
+ this.argCounts = pack(rslotCount, rtypeCount, pslotCount, ptypeCount);
+ this.argToSlotTable = argToSlotTab;
+ this.slotToArgTable = slotToArgTab;
+
+ if (pslotCount >= 256) throw newIllegalArgumentException("too many arguments");
+
+ // Initialize caches, but only for basic types
+ assert(basicType == erasedType);
+ this.lambdaForms = new SoftReference[LF_LIMIT];
+ this.methodHandles = new SoftReference[MH_LIMIT];
+ }
+
+ private static long pack(int a, int b, int c, int d) {
+ assert(((a|b|c|d) & ~0xFFFF) == 0);
+ long hw = ((a << 16) | b), lw = ((c << 16) | d);
+ return (hw << 32) | lw;
+ }
+ private static char unpack(long packed, int word) { // word==0 => return a, ==3 => return d
+ assert(word <= 3);
+ return (char)(packed >> ((3-word) * 16));
+ }
+
+ public int parameterCount() { // # outgoing values
+ return unpack(argCounts, 3);
+ }
+ public int parameterSlotCount() { // # outgoing interpreter slots
+ return unpack(argCounts, 2);
+ }
+ public int returnCount() { // = 0 (V), or 1
+ return unpack(argCounts, 1);
+ }
+ public int returnSlotCount() { // = 0 (V), 2 (J/D), or 1
+ return unpack(argCounts, 0);
+ }
+ public int primitiveParameterCount() {
+ return unpack(primCounts, 3);
+ }
+ public int longPrimitiveParameterCount() {
+ return unpack(primCounts, 2);
+ }
+ public int primitiveReturnCount() { // = 0 (obj), or 1
+ return unpack(primCounts, 1);
+ }
+ public int longPrimitiveReturnCount() { // = 1 (J/D), or 0
+ return unpack(primCounts, 0);
+ }
+ public boolean hasPrimitives() {
+ return primCounts != 0;
+ }
+ public boolean hasNonVoidPrimitives() {
+ if (primCounts == 0) return false;
+ if (primitiveParameterCount() != 0) return true;
+ return (primitiveReturnCount() != 0 && returnCount() != 0);
+ }
+ public boolean hasLongPrimitives() {
+ return (longPrimitiveParameterCount() | longPrimitiveReturnCount()) != 0;
+ }
+ public int parameterToArgSlot(int i) {
+ return argToSlotTable[1+i];
+ }
+ public int argSlotToParameter(int argSlot) {
+ // Note: Empty slots are represented by zero in this table.
+ // Valid arguments slots contain incremented entries, so as to be non-zero.
+ // We return -1 the caller to mean an empty slot.
+ return slotToArgTable[argSlot] - 1;
+ }
+
+ static MethodTypeForm findForm(MethodType mt) {
+ MethodType erased = canonicalize(mt, ERASE, ERASE);
+ if (erased == null) {
+ // It is already erased. Make a new MethodTypeForm.
+ return new MethodTypeForm(mt);
+ } else {
+ // Share the MethodTypeForm with the erased version.
+ return erased.form();
+ }
+ }
+
+ /** Codes for {@link #canonicalize(java.lang.Class, int)}.
+ * ERASE means change every reference to {@code Object}.
+ * WRAP means convert primitives (including {@code void} to their
+ * corresponding wrapper types. UNWRAP means the reverse of WRAP.
+ * INTS means convert all non-void primitive types to int or long,
+ * according to size. LONGS means convert all non-void primitives
+ * to long, regardless of size. RAW_RETURN means convert a type
+ * (assumed to be a return type) to int if it is smaller than an int,
+ * or if it is void.
+ */
+ public static final int NO_CHANGE = 0, ERASE = 1, WRAP = 2, UNWRAP = 3, INTS = 4, LONGS = 5, RAW_RETURN = 6;
+
+ /** Canonicalize the types in the given method type.
+ * If any types change, intern the new type, and return it.
+ * Otherwise return null.
+ */
+ public static MethodType canonicalize(MethodType mt, int howRet, int howArgs) {
+ Class<?>[] ptypes = mt.ptypes();
+ Class<?>[] ptc = MethodTypeForm.canonicalizeAll(ptypes, howArgs);
+ Class<?> rtype = mt.returnType();
+ Class<?> rtc = MethodTypeForm.canonicalize(rtype, howRet);
+ if (ptc == null && rtc == null) {
+ // It is already canonical.
+ return null;
+ }
+ // Find the erased version of the method type:
+ if (rtc == null) rtc = rtype;
+ if (ptc == null) ptc = ptypes;
+ return MethodType.makeImpl(rtc, ptc, true);
+ }
+
+ /** Canonicalize the given return or param type.
+ * Return null if the type is already canonicalized.
+ */
+ static Class<?> canonicalize(Class<?> t, int how) {
+ Class<?> ct;
+ if (t == Object.class) {
+ // no change, ever
+ } else if (!t.isPrimitive()) {
+ switch (how) {
+ case UNWRAP:
+ ct = Wrapper.asPrimitiveType(t);
+ if (ct != t) return ct;
+ break;
+ case RAW_RETURN:
+ case ERASE:
+ return Object.class;
+ }
+ } else if (t == void.class) {
+ // no change, usually
+ switch (how) {
+ case RAW_RETURN:
+ return int.class;
+ case WRAP:
+ return Void.class;
+ }
+ } else {
+ // non-void primitive
+ switch (how) {
+ case WRAP:
+ return Wrapper.asWrapperType(t);
+ case INTS:
+ if (t == int.class || t == long.class)
+ return null; // no change
+ if (t == double.class)
+ return long.class;
+ return int.class;
+ case LONGS:
+ if (t == long.class)
+ return null; // no change
+ return long.class;
+ case RAW_RETURN:
+ if (t == int.class || t == long.class ||
+ t == float.class || t == double.class)
+ return null; // no change
+ // everything else returns as an int
+ return int.class;
+ }
+ }
+ // no change; return null to signify
+ return null;
+ }
+
+ /** Canonicalize each param type in the given array.
+ * Return null if all types are already canonicalized.
+ */
+ static Class<?>[] canonicalizeAll(Class<?>[] ts, int how) {
+ Class<?>[] cs = null;
+ for (int imax = ts.length, i = 0; i < imax; i++) {
+ Class<?> c = canonicalize(ts[i], how);
+ if (c == void.class)
+ c = null; // a Void parameter was unwrapped to void; ignore
+ if (c != null) {
+ if (cs == null)
+ cs = ts.clone();
+ cs[i] = c;
+ }
+ }
+ return cs;
+ }
+
+ @Override
+ public String toString() {
+ return "Form"+erasedType;
+ }
+}