| /* |
| * 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; |
| } |
| } |