diff -r 000000000000 -r c880a8a8803b rt/emul/compact/src/main/java/java/lang/invoke/MethodTypeForm.java --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/rt/emul/compact/src/main/java/java/lang/invoke/MethodTypeForm.java Sat Aug 09 11:11:13 2014 +0200 @@ -0,0 +1,388 @@ +/* + * Copyright (c) 2008, 2013, 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 sun.invoke.util.Wrapper; +import static java.lang.invoke.MethodHandleStatics.*; +import static java.lang.invoke.MethodHandleNatives.Constants.*; + import static java.lang.invoke.MethodHandles.Lookup.IMPL_LOOKUP; + +/** + * Shared information for a group of method types, which differ + * only by reference types, and therefore share a common erasure + * and wrapping. + *

+ * For an empirical discussion of the structure of method types, + * see + * the thread "Avoiding Boxing" on jvm-languages. + * 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 int vmslots; // total number of parameter slots + final MethodType erasedType; // the canonical erasure + final MethodType basicType; // the canonical erasure, with primitives simplified + + // Cached adapter information: + @Stable String typeString; // argument type signature characters + @Stable MethodHandle genericInvoker; // JVM hook for inexact invoke + @Stable MethodHandle basicInvoker; // cached instance of MH.invokeBasic + @Stable MethodHandle namedFunctionInvoker; // cached helper for LF.NamedFunction + + // Cached lambda form information, for basic types only: + final @Stable 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 barrier + LF_INTERPRET = 6, // LF interpreter + LF_COUNTER = 7, // CMH wrapper + LF_REINVOKE = 8, // other wrapper + LF_EX_LINKER = 9, // invokeExact_MT + LF_EX_INVOKER = 10, // invokeExact MH + LF_GEN_LINKER = 11, + LF_GEN_INVOKER = 12, + LF_CS_LINKER = 13, // linkToCallSite_CS + LF_MH_LINKER = 14, // linkToCallSite_MH + LF_LIMIT = 15; + + public MethodType erasedType() { + return erasedType; + } + + public MethodType basicType() { + return basicType; + } + + public LambdaForm cachedLambdaForm(int which) { + return lambdaForms[which]; + } + + public LambdaForm setCachedLambdaForm(int which, LambdaForm form) { + // Should we perform some sort of CAS, to avoid racy duplication? + return lambdaForms[which] = form; + } + + public MethodHandle basicInvoker() { + assert(erasedType == basicType) : "erasedType: " + erasedType + " != basicType: " + basicType; // primitives must be flattened also + MethodHandle invoker = basicInvoker; + if (invoker != null) return invoker; + invoker = DirectMethodHandle.make(invokeBasicMethod(basicType)); + basicInvoker = invoker; + return invoker; + } + + // This next one is called from LambdaForm.NamedFunction.. + /*non-public*/ static MemberName invokeBasicMethod(MethodType basicType) { + assert(basicType == basicType.basicType()); + try { + // Do approximately the same as this public API call: + // Lookup.findVirtual(MethodHandle.class, name, type); + // But bypass access and corner case checks, since we know exactly what we need. + return IMPL_LOOKUP.resolveOrFail(REF_invokeVirtual, MethodHandle.class, "invokeBasic", basicType); + } catch (ReflectiveOperationException ex) { + throw newInternalError("JVM cannot find invoker for "+basicType, ex); + } + } + + /** + * 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. + */ + 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); + } + 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 + } + this.primCounts = pack(lrc, prc, lac, pac); + this.argCounts = pack(rslotCount, rtypeCount, pslotCount, ptypeCount); + if (slotToArgTab == null) { + 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.argToSlotTable = argToSlotTab; + this.slotToArgTable = slotToArgTab; + + if (pslotCount >= 256) throw newIllegalArgumentException("too many arguments"); + + // send a few bits down to the JVM: + this.vmslots = parameterSlotCount(); + + if (basicType == erasedType) { + lambdaForms = new LambdaForm[LF_LIMIT]; + } else { + lambdaForms = null; // could be basicType.form().lambdaForms; + } + } + + 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.canonicalizes(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[] canonicalizes(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; + } + +}