1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/rt/emul/compact/src/main/java/java/lang/invoke/MethodTypeForm.java Sat Aug 09 11:11:13 2014 +0200
1.3 @@ -0,0 +1,388 @@
1.4 +/*
1.5 + * Copyright (c) 2008, 2013, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation. Oracle designates this
1.11 + * particular file as subject to the "Classpath" exception as provided
1.12 + * by Oracle in the LICENSE file that accompanied this code.
1.13 + *
1.14 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.15 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.16 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.17 + * version 2 for more details (a copy is included in the LICENSE file that
1.18 + * accompanied this code).
1.19 + *
1.20 + * You should have received a copy of the GNU General Public License version
1.21 + * 2 along with this work; if not, write to the Free Software Foundation,
1.22 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.23 + *
1.24 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.25 + * or visit www.oracle.com if you need additional information or have any
1.26 + * questions.
1.27 + */
1.28 +
1.29 +package java.lang.invoke;
1.30 +
1.31 +import sun.invoke.util.Wrapper;
1.32 +import static java.lang.invoke.MethodHandleStatics.*;
1.33 +import static java.lang.invoke.MethodHandleNatives.Constants.*;
1.34 + import static java.lang.invoke.MethodHandles.Lookup.IMPL_LOOKUP;
1.35 +
1.36 +/**
1.37 + * Shared information for a group of method types, which differ
1.38 + * only by reference types, and therefore share a common erasure
1.39 + * and wrapping.
1.40 + * <p>
1.41 + * For an empirical discussion of the structure of method types,
1.42 + * see <a href="http://groups.google.com/group/jvm-languages/browse_thread/thread/ac9308ae74da9b7e/">
1.43 + * the thread "Avoiding Boxing" on jvm-languages</a>.
1.44 + * There are approximately 2000 distinct erased method types in the JDK.
1.45 + * There are a little over 10 times that number of unerased types.
1.46 + * No more than half of these are likely to be loaded at once.
1.47 + * @author John Rose
1.48 + */
1.49 +final class MethodTypeForm {
1.50 + final int[] argToSlotTable, slotToArgTable;
1.51 + final long argCounts; // packed slot & value counts
1.52 + final long primCounts; // packed prim & double counts
1.53 + final int vmslots; // total number of parameter slots
1.54 + final MethodType erasedType; // the canonical erasure
1.55 + final MethodType basicType; // the canonical erasure, with primitives simplified
1.56 +
1.57 + // Cached adapter information:
1.58 + @Stable String typeString; // argument type signature characters
1.59 + @Stable MethodHandle genericInvoker; // JVM hook for inexact invoke
1.60 + @Stable MethodHandle basicInvoker; // cached instance of MH.invokeBasic
1.61 + @Stable MethodHandle namedFunctionInvoker; // cached helper for LF.NamedFunction
1.62 +
1.63 + // Cached lambda form information, for basic types only:
1.64 + final @Stable LambdaForm[] lambdaForms;
1.65 + // Indexes into lambdaForms:
1.66 + static final int
1.67 + LF_INVVIRTUAL = 0, // DMH invokeVirtual
1.68 + LF_INVSTATIC = 1,
1.69 + LF_INVSPECIAL = 2,
1.70 + LF_NEWINVSPECIAL = 3,
1.71 + LF_INVINTERFACE = 4,
1.72 + LF_INVSTATIC_INIT = 5, // DMH invokeStatic with <clinit> barrier
1.73 + LF_INTERPRET = 6, // LF interpreter
1.74 + LF_COUNTER = 7, // CMH wrapper
1.75 + LF_REINVOKE = 8, // other wrapper
1.76 + LF_EX_LINKER = 9, // invokeExact_MT
1.77 + LF_EX_INVOKER = 10, // invokeExact MH
1.78 + LF_GEN_LINKER = 11,
1.79 + LF_GEN_INVOKER = 12,
1.80 + LF_CS_LINKER = 13, // linkToCallSite_CS
1.81 + LF_MH_LINKER = 14, // linkToCallSite_MH
1.82 + LF_LIMIT = 15;
1.83 +
1.84 + public MethodType erasedType() {
1.85 + return erasedType;
1.86 + }
1.87 +
1.88 + public MethodType basicType() {
1.89 + return basicType;
1.90 + }
1.91 +
1.92 + public LambdaForm cachedLambdaForm(int which) {
1.93 + return lambdaForms[which];
1.94 + }
1.95 +
1.96 + public LambdaForm setCachedLambdaForm(int which, LambdaForm form) {
1.97 + // Should we perform some sort of CAS, to avoid racy duplication?
1.98 + return lambdaForms[which] = form;
1.99 + }
1.100 +
1.101 + public MethodHandle basicInvoker() {
1.102 + assert(erasedType == basicType) : "erasedType: " + erasedType + " != basicType: " + basicType; // primitives must be flattened also
1.103 + MethodHandle invoker = basicInvoker;
1.104 + if (invoker != null) return invoker;
1.105 + invoker = DirectMethodHandle.make(invokeBasicMethod(basicType));
1.106 + basicInvoker = invoker;
1.107 + return invoker;
1.108 + }
1.109 +
1.110 + // This next one is called from LambdaForm.NamedFunction.<init>.
1.111 + /*non-public*/ static MemberName invokeBasicMethod(MethodType basicType) {
1.112 + assert(basicType == basicType.basicType());
1.113 + try {
1.114 + // Do approximately the same as this public API call:
1.115 + // Lookup.findVirtual(MethodHandle.class, name, type);
1.116 + // But bypass access and corner case checks, since we know exactly what we need.
1.117 + return IMPL_LOOKUP.resolveOrFail(REF_invokeVirtual, MethodHandle.class, "invokeBasic", basicType);
1.118 + } catch (ReflectiveOperationException ex) {
1.119 + throw newInternalError("JVM cannot find invoker for "+basicType, ex);
1.120 + }
1.121 + }
1.122 +
1.123 + /**
1.124 + * Build an MTF for a given type, which must have all references erased to Object.
1.125 + * This MTF will stand for that type and all un-erased variations.
1.126 + * Eagerly compute some basic properties of the type, common to all variations.
1.127 + */
1.128 + protected MethodTypeForm(MethodType erasedType) {
1.129 + this.erasedType = erasedType;
1.130 +
1.131 + Class<?>[] ptypes = erasedType.ptypes();
1.132 + int ptypeCount = ptypes.length;
1.133 + int pslotCount = ptypeCount; // temp. estimate
1.134 + int rtypeCount = 1; // temp. estimate
1.135 + int rslotCount = 1; // temp. estimate
1.136 +
1.137 + int[] argToSlotTab = null, slotToArgTab = null;
1.138 +
1.139 + // Walk the argument types, looking for primitives.
1.140 + int pac = 0, lac = 0, prc = 0, lrc = 0;
1.141 + Class<?>[] epts = ptypes;
1.142 + Class<?>[] bpts = epts;
1.143 + for (int i = 0; i < epts.length; i++) {
1.144 + Class<?> pt = epts[i];
1.145 + if (pt != Object.class) {
1.146 + ++pac;
1.147 + Wrapper w = Wrapper.forPrimitiveType(pt);
1.148 + if (w.isDoubleWord()) ++lac;
1.149 + if (w.isSubwordOrInt() && pt != int.class) {
1.150 + if (bpts == epts)
1.151 + bpts = bpts.clone();
1.152 + bpts[i] = int.class;
1.153 + }
1.154 + }
1.155 + }
1.156 + pslotCount += lac; // #slots = #args + #longs
1.157 + Class<?> rt = erasedType.returnType();
1.158 + Class<?> bt = rt;
1.159 + if (rt != Object.class) {
1.160 + ++prc; // even void.class counts as a prim here
1.161 + Wrapper w = Wrapper.forPrimitiveType(rt);
1.162 + if (w.isDoubleWord()) ++lrc;
1.163 + if (w.isSubwordOrInt() && rt != int.class)
1.164 + bt = int.class;
1.165 + // adjust #slots, #args
1.166 + if (rt == void.class)
1.167 + rtypeCount = rslotCount = 0;
1.168 + else
1.169 + rslotCount += lrc;
1.170 + }
1.171 + if (epts == bpts && bt == rt) {
1.172 + this.basicType = erasedType;
1.173 + } else {
1.174 + this.basicType = MethodType.makeImpl(bt, bpts, true);
1.175 + }
1.176 + if (lac != 0) {
1.177 + int slot = ptypeCount + lac;
1.178 + slotToArgTab = new int[slot+1];
1.179 + argToSlotTab = new int[1+ptypeCount];
1.180 + argToSlotTab[0] = slot; // argument "-1" is past end of slots
1.181 + for (int i = 0; i < epts.length; i++) {
1.182 + Class<?> pt = epts[i];
1.183 + Wrapper w = Wrapper.forBasicType(pt);
1.184 + if (w.isDoubleWord()) --slot;
1.185 + --slot;
1.186 + slotToArgTab[slot] = i+1; // "+1" see argSlotToParameter note
1.187 + argToSlotTab[1+i] = slot;
1.188 + }
1.189 + assert(slot == 0); // filled the table
1.190 + }
1.191 + this.primCounts = pack(lrc, prc, lac, pac);
1.192 + this.argCounts = pack(rslotCount, rtypeCount, pslotCount, ptypeCount);
1.193 + if (slotToArgTab == null) {
1.194 + int slot = ptypeCount; // first arg is deepest in stack
1.195 + slotToArgTab = new int[slot+1];
1.196 + argToSlotTab = new int[1+ptypeCount];
1.197 + argToSlotTab[0] = slot; // argument "-1" is past end of slots
1.198 + for (int i = 0; i < ptypeCount; i++) {
1.199 + --slot;
1.200 + slotToArgTab[slot] = i+1; // "+1" see argSlotToParameter note
1.201 + argToSlotTab[1+i] = slot;
1.202 + }
1.203 + }
1.204 + this.argToSlotTable = argToSlotTab;
1.205 + this.slotToArgTable = slotToArgTab;
1.206 +
1.207 + if (pslotCount >= 256) throw newIllegalArgumentException("too many arguments");
1.208 +
1.209 + // send a few bits down to the JVM:
1.210 + this.vmslots = parameterSlotCount();
1.211 +
1.212 + if (basicType == erasedType) {
1.213 + lambdaForms = new LambdaForm[LF_LIMIT];
1.214 + } else {
1.215 + lambdaForms = null; // could be basicType.form().lambdaForms;
1.216 + }
1.217 + }
1.218 +
1.219 + private static long pack(int a, int b, int c, int d) {
1.220 + assert(((a|b|c|d) & ~0xFFFF) == 0);
1.221 + long hw = ((a << 16) | b), lw = ((c << 16) | d);
1.222 + return (hw << 32) | lw;
1.223 + }
1.224 + private static char unpack(long packed, int word) { // word==0 => return a, ==3 => return d
1.225 + assert(word <= 3);
1.226 + return (char)(packed >> ((3-word) * 16));
1.227 + }
1.228 +
1.229 + public int parameterCount() { // # outgoing values
1.230 + return unpack(argCounts, 3);
1.231 + }
1.232 + public int parameterSlotCount() { // # outgoing interpreter slots
1.233 + return unpack(argCounts, 2);
1.234 + }
1.235 + public int returnCount() { // = 0 (V), or 1
1.236 + return unpack(argCounts, 1);
1.237 + }
1.238 + public int returnSlotCount() { // = 0 (V), 2 (J/D), or 1
1.239 + return unpack(argCounts, 0);
1.240 + }
1.241 + public int primitiveParameterCount() {
1.242 + return unpack(primCounts, 3);
1.243 + }
1.244 + public int longPrimitiveParameterCount() {
1.245 + return unpack(primCounts, 2);
1.246 + }
1.247 + public int primitiveReturnCount() { // = 0 (obj), or 1
1.248 + return unpack(primCounts, 1);
1.249 + }
1.250 + public int longPrimitiveReturnCount() { // = 1 (J/D), or 0
1.251 + return unpack(primCounts, 0);
1.252 + }
1.253 + public boolean hasPrimitives() {
1.254 + return primCounts != 0;
1.255 + }
1.256 + public boolean hasNonVoidPrimitives() {
1.257 + if (primCounts == 0) return false;
1.258 + if (primitiveParameterCount() != 0) return true;
1.259 + return (primitiveReturnCount() != 0 && returnCount() != 0);
1.260 + }
1.261 + public boolean hasLongPrimitives() {
1.262 + return (longPrimitiveParameterCount() | longPrimitiveReturnCount()) != 0;
1.263 + }
1.264 + public int parameterToArgSlot(int i) {
1.265 + return argToSlotTable[1+i];
1.266 + }
1.267 + public int argSlotToParameter(int argSlot) {
1.268 + // Note: Empty slots are represented by zero in this table.
1.269 + // Valid arguments slots contain incremented entries, so as to be non-zero.
1.270 + // We return -1 the caller to mean an empty slot.
1.271 + return slotToArgTable[argSlot] - 1;
1.272 + }
1.273 +
1.274 + static MethodTypeForm findForm(MethodType mt) {
1.275 + MethodType erased = canonicalize(mt, ERASE, ERASE);
1.276 + if (erased == null) {
1.277 + // It is already erased. Make a new MethodTypeForm.
1.278 + return new MethodTypeForm(mt);
1.279 + } else {
1.280 + // Share the MethodTypeForm with the erased version.
1.281 + return erased.form();
1.282 + }
1.283 + }
1.284 +
1.285 + /** Codes for {@link #canonicalize(java.lang.Class, int)}.
1.286 + * ERASE means change every reference to {@code Object}.
1.287 + * WRAP means convert primitives (including {@code void} to their
1.288 + * corresponding wrapper types. UNWRAP means the reverse of WRAP.
1.289 + * INTS means convert all non-void primitive types to int or long,
1.290 + * according to size. LONGS means convert all non-void primitives
1.291 + * to long, regardless of size. RAW_RETURN means convert a type
1.292 + * (assumed to be a return type) to int if it is smaller than an int,
1.293 + * or if it is void.
1.294 + */
1.295 + public static final int NO_CHANGE = 0, ERASE = 1, WRAP = 2, UNWRAP = 3, INTS = 4, LONGS = 5, RAW_RETURN = 6;
1.296 +
1.297 + /** Canonicalize the types in the given method type.
1.298 + * If any types change, intern the new type, and return it.
1.299 + * Otherwise return null.
1.300 + */
1.301 + public static MethodType canonicalize(MethodType mt, int howRet, int howArgs) {
1.302 + Class<?>[] ptypes = mt.ptypes();
1.303 + Class<?>[] ptc = MethodTypeForm.canonicalizes(ptypes, howArgs);
1.304 + Class<?> rtype = mt.returnType();
1.305 + Class<?> rtc = MethodTypeForm.canonicalize(rtype, howRet);
1.306 + if (ptc == null && rtc == null) {
1.307 + // It is already canonical.
1.308 + return null;
1.309 + }
1.310 + // Find the erased version of the method type:
1.311 + if (rtc == null) rtc = rtype;
1.312 + if (ptc == null) ptc = ptypes;
1.313 + return MethodType.makeImpl(rtc, ptc, true);
1.314 + }
1.315 +
1.316 + /** Canonicalize the given return or param type.
1.317 + * Return null if the type is already canonicalized.
1.318 + */
1.319 + static Class<?> canonicalize(Class<?> t, int how) {
1.320 + Class<?> ct;
1.321 + if (t == Object.class) {
1.322 + // no change, ever
1.323 + } else if (!t.isPrimitive()) {
1.324 + switch (how) {
1.325 + case UNWRAP:
1.326 + ct = Wrapper.asPrimitiveType(t);
1.327 + if (ct != t) return ct;
1.328 + break;
1.329 + case RAW_RETURN:
1.330 + case ERASE:
1.331 + return Object.class;
1.332 + }
1.333 + } else if (t == void.class) {
1.334 + // no change, usually
1.335 + switch (how) {
1.336 + case RAW_RETURN:
1.337 + return int.class;
1.338 + case WRAP:
1.339 + return Void.class;
1.340 + }
1.341 + } else {
1.342 + // non-void primitive
1.343 + switch (how) {
1.344 + case WRAP:
1.345 + return Wrapper.asWrapperType(t);
1.346 + case INTS:
1.347 + if (t == int.class || t == long.class)
1.348 + return null; // no change
1.349 + if (t == double.class)
1.350 + return long.class;
1.351 + return int.class;
1.352 + case LONGS:
1.353 + if (t == long.class)
1.354 + return null; // no change
1.355 + return long.class;
1.356 + case RAW_RETURN:
1.357 + if (t == int.class || t == long.class ||
1.358 + t == float.class || t == double.class)
1.359 + return null; // no change
1.360 + // everything else returns as an int
1.361 + return int.class;
1.362 + }
1.363 + }
1.364 + // no change; return null to signify
1.365 + return null;
1.366 + }
1.367 +
1.368 + /** Canonicalize each param type in the given array.
1.369 + * Return null if all types are already canonicalized.
1.370 + */
1.371 + static Class<?>[] canonicalizes(Class<?>[] ts, int how) {
1.372 + Class<?>[] cs = null;
1.373 + for (int imax = ts.length, i = 0; i < imax; i++) {
1.374 + Class<?> c = canonicalize(ts[i], how);
1.375 + if (c == void.class)
1.376 + c = null; // a Void parameter was unwrapped to void; ignore
1.377 + if (c != null) {
1.378 + if (cs == null)
1.379 + cs = ts.clone();
1.380 + cs[i] = c;
1.381 + }
1.382 + }
1.383 + return cs;
1.384 + }
1.385 +
1.386 + @Override
1.387 + public String toString() {
1.388 + return "Form"+erasedType;
1.389 + }
1.390 +
1.391 +}