Mercurial > hg > graal-compiler
view graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/replacements/MonitorSnippets.java @ 23058:2b27fb937568
Fix compiler warning.
author | Thomas Wuerthinger <thomas.wuerthinger@oracle.com> |
---|---|
date | Sun, 22 Nov 2015 14:53:59 +0100 |
parents | c039bbe02458 |
children | b00ef2b9cd00 |
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/* * Copyright (c) 2012, 2015, 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. * * 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 com.oracle.graal.hotspot.replacements; import static com.oracle.graal.compiler.common.GraalOptions.SnippetCounters; import static com.oracle.graal.hotspot.nodes.BeginLockScopeNode.beginLockScope; import static com.oracle.graal.hotspot.nodes.DirectCompareAndSwapNode.compareAndSwap; import static com.oracle.graal.hotspot.nodes.EndLockScopeNode.endLockScope; import static com.oracle.graal.hotspot.nodes.VMErrorNode.vmError; import static com.oracle.graal.hotspot.replacements.HotSpotReplacementsUtil.DISPLACED_MARK_WORD_LOCATION; import static com.oracle.graal.hotspot.replacements.HotSpotReplacementsUtil.MARK_WORD_LOCATION; import static com.oracle.graal.hotspot.replacements.HotSpotReplacementsUtil.PROTOTYPE_MARK_WORD_LOCATION; import static com.oracle.graal.hotspot.replacements.HotSpotReplacementsUtil.ageMaskInPlace; import static com.oracle.graal.hotspot.replacements.HotSpotReplacementsUtil.biasedLockMaskInPlace; import static com.oracle.graal.hotspot.replacements.HotSpotReplacementsUtil.biasedLockPattern; import static com.oracle.graal.hotspot.replacements.HotSpotReplacementsUtil.config; import static com.oracle.graal.hotspot.replacements.HotSpotReplacementsUtil.epochMaskInPlace; import static com.oracle.graal.hotspot.replacements.HotSpotReplacementsUtil.loadWordFromObject; import static com.oracle.graal.hotspot.replacements.HotSpotReplacementsUtil.lockDisplacedMarkOffset; import static com.oracle.graal.hotspot.replacements.HotSpotReplacementsUtil.markOffset; import static com.oracle.graal.hotspot.replacements.HotSpotReplacementsUtil.pageSize; import static com.oracle.graal.hotspot.replacements.HotSpotReplacementsUtil.prototypeMarkWordOffset; import static com.oracle.graal.hotspot.replacements.HotSpotReplacementsUtil.registerAsWord; import static com.oracle.graal.hotspot.replacements.HotSpotReplacementsUtil.unlockedMask; import static com.oracle.graal.hotspot.replacements.HotSpotReplacementsUtil.useBiasedLocking; import static com.oracle.graal.hotspot.replacements.HotSpotReplacementsUtil.verifyOop; import static com.oracle.graal.hotspot.replacements.HotSpotReplacementsUtil.wordSize; import static com.oracle.graal.nodes.extended.BranchProbabilityNode.FREQUENT_PROBABILITY; import static com.oracle.graal.nodes.extended.BranchProbabilityNode.VERY_FAST_PATH_PROBABILITY; import static com.oracle.graal.nodes.extended.BranchProbabilityNode.VERY_SLOW_PATH_PROBABILITY; import static com.oracle.graal.nodes.extended.BranchProbabilityNode.probability; import static com.oracle.graal.replacements.SnippetTemplate.DEFAULT_REPLACER; import java.util.List; import jdk.vm.ci.code.BytecodeFrame; import jdk.vm.ci.code.Register; import jdk.vm.ci.code.TargetDescription; import jdk.vm.ci.meta.DeoptimizationAction; import jdk.vm.ci.meta.DeoptimizationReason; import jdk.vm.ci.meta.JavaType; import jdk.vm.ci.meta.LocationIdentity; import jdk.vm.ci.meta.ResolvedJavaMethod; import jdk.vm.ci.meta.ResolvedJavaType; import jdk.vm.ci.options.Option; import jdk.vm.ci.options.OptionType; import jdk.vm.ci.options.OptionValue; import com.oracle.graal.api.replacements.Fold; import com.oracle.graal.compiler.common.spi.ForeignCallDescriptor; import com.oracle.graal.compiler.common.type.ObjectStamp; import com.oracle.graal.graph.Node.ConstantNodeParameter; import com.oracle.graal.graph.Node.NodeIntrinsic; import com.oracle.graal.graph.iterators.NodeIterable; import com.oracle.graal.hotspot.meta.HotSpotProviders; import com.oracle.graal.hotspot.meta.HotSpotRegistersProvider; import com.oracle.graal.hotspot.nodes.CurrentLockNode; import com.oracle.graal.hotspot.nodes.DirectCompareAndSwapNode; import com.oracle.graal.hotspot.nodes.FastAcquireBiasedLockNode; import com.oracle.graal.hotspot.nodes.MonitorCounterNode; import com.oracle.graal.hotspot.word.KlassPointer; import com.oracle.graal.nodes.BreakpointNode; import com.oracle.graal.nodes.CallTargetNode.InvokeKind; import com.oracle.graal.nodes.ConstantNode; import com.oracle.graal.nodes.DeoptimizeNode; import com.oracle.graal.nodes.FrameState; import com.oracle.graal.nodes.InvokeNode; import com.oracle.graal.nodes.NamedLocationIdentity; import com.oracle.graal.nodes.ReturnNode; import com.oracle.graal.nodes.StructuredGraph; import com.oracle.graal.nodes.ValueNode; import com.oracle.graal.nodes.debug.DynamicCounterNode; import com.oracle.graal.nodes.extended.BranchProbabilityNode; import com.oracle.graal.nodes.extended.ForeignCallNode; import com.oracle.graal.nodes.java.MethodCallTargetNode; import com.oracle.graal.nodes.java.MonitorExitNode; import com.oracle.graal.nodes.java.RawMonitorEnterNode; import com.oracle.graal.nodes.memory.address.OffsetAddressNode; import com.oracle.graal.nodes.spi.LoweringTool; import com.oracle.graal.nodes.type.StampTool; import com.oracle.graal.phases.common.inlining.InliningUtil; import com.oracle.graal.replacements.Log; import com.oracle.graal.replacements.Snippet; import com.oracle.graal.replacements.Snippet.ConstantParameter; import com.oracle.graal.replacements.SnippetCounter; import com.oracle.graal.replacements.SnippetTemplate.AbstractTemplates; import com.oracle.graal.replacements.SnippetTemplate.Arguments; import com.oracle.graal.replacements.SnippetTemplate.SnippetInfo; import com.oracle.graal.replacements.Snippets; import com.oracle.graal.word.Word; import com.oracle.graal.word.WordBase; /** * Snippets used for implementing the monitorenter and monitorexit instructions. * * The locking algorithm used is described in the paper <a * href="http://dl.acm.org/citation.cfm?id=1167515.1167496"> Eliminating synchronization-related * atomic operations with biased locking and bulk rebiasing</a> by Kenneth Russell and David * Detlefs. * * Comment below is reproduced from {@code markOop.hpp} for convenience: * * <pre> * Bit-format of an object header (most significant first, big endian layout below): * 32 bits: * -------- * hash:25 ------------>| age:4 biased_lock:1 lock:2 (normal object) * JavaThread*:23 epoch:2 age:4 biased_lock:1 lock:2 (biased object) * size:32 ------------------------------------------>| (CMS free block) * PromotedObject*:29 ---------->| promo_bits:3 ----->| (CMS promoted object) * * 64 bits: * -------- * unused:25 hash:31 -->| unused:1 age:4 biased_lock:1 lock:2 (normal object) * JavaThread*:54 epoch:2 unused:1 age:4 biased_lock:1 lock:2 (biased object) * PromotedObject*:61 --------------------->| promo_bits:3 ----->| (CMS promoted object) * size:64 ----------------------------------------------------->| (CMS free block) * * unused:25 hash:31 -->| cms_free:1 age:4 biased_lock:1 lock:2 (COOPs && normal object) * JavaThread*:54 epoch:2 cms_free:1 age:4 biased_lock:1 lock:2 (COOPs && biased object) * narrowOop:32 unused:24 cms_free:1 unused:4 promo_bits:3 ----->| (COOPs && CMS promoted object) * unused:21 size:35 -->| cms_free:1 unused:7 ------------------>| (COOPs && CMS free block) * * - hash contains the identity hash value: largest value is * 31 bits, see os::random(). Also, 64-bit vm's require * a hash value no bigger than 32 bits because they will not * properly generate a mask larger than that: see library_call.cpp * and c1_CodePatterns_sparc.cpp. * * - the biased lock pattern is used to bias a lock toward a given * thread. When this pattern is set in the low three bits, the lock * is either biased toward a given thread or "anonymously" biased, * indicating that it is possible for it to be biased. When the * lock is biased toward a given thread, locking and unlocking can * be performed by that thread without using atomic operations. * When a lock's bias is revoked, it reverts back to the normal * locking scheme described below. * * Note that we are overloading the meaning of the "unlocked" state * of the header. Because we steal a bit from the age we can * guarantee that the bias pattern will never be seen for a truly * unlocked object. * * Note also that the biased state contains the age bits normally * contained in the object header. Large increases in scavenge * times were seen when these bits were absent and an arbitrary age * assigned to all biased objects, because they tended to consume a * significant fraction of the eden semispaces and were not * promoted promptly, causing an increase in the amount of copying * performed. The runtime system aligns all JavaThread* pointers to * a very large value (currently 128 bytes (32bVM) or 256 bytes (64bVM)) * to make room for the age bits & the epoch bits (used in support of * biased locking), and for the CMS "freeness" bit in the 64bVM (+COOPs). * * [JavaThread* | epoch | age | 1 | 01] lock is biased toward given thread * [0 | epoch | age | 1 | 01] lock is anonymously biased * * - the two lock bits are used to describe three states: locked/unlocked and monitor. * * [ptr | 00] locked ptr points to real header on stack * [header | 0 | 01] unlocked regular object header * [ptr | 10] monitor inflated lock (header is wapped out) * [ptr | 11] marked used by markSweep to mark an object * not valid at any other time * * We assume that stack/thread pointers have the lowest two bits cleared. * </pre> * * Note that {@code Thread::allocate} enforces {@code JavaThread} objects to be aligned * appropriately to comply with the layouts above. */ public class MonitorSnippets implements Snippets { public static class Options { //@formatter:off @Option(help = "", type = OptionType.Debug) private static final OptionValue<Boolean> ProfileMonitors = new OptionValue<>(false); //@formatter:on } private static final boolean PROFILE_CONTEXT = false; @Fold private static boolean doProfile() { return Options.ProfileMonitors.getValue(); } /** * Monitor operations on objects whose type contains this substring will be traced. */ private static final String TRACE_TYPE_FILTER = System.getProperty("graal.monitors.trace.typeFilter"); /** * Monitor operations in methods whose fully qualified name contains this substring will be * traced. */ private static final String TRACE_METHOD_FILTER = System.getProperty("graal.monitors.trace.methodFilter"); public static final boolean CHECK_BALANCED_MONITORS = Boolean.getBoolean("graal.monitors.checkBalanced"); @Snippet public static void monitorenter(Object object, KlassPointer hub, @ConstantParameter int lockDepth, @ConstantParameter Register threadRegister, @ConstantParameter Register stackPointerRegister, @ConstantParameter boolean trace) { verifyOop(object); // Load the mark word - this includes a null-check on object final Word mark = loadWordFromObject(object, markOffset()); final Word lock = beginLockScope(lockDepth); trace(trace, " object: 0x%016lx\n", Word.objectToTrackedPointer(object)); trace(trace, " lock: 0x%016lx\n", lock); trace(trace, " mark: 0x%016lx\n", mark); incCounter(); if (useBiasedLocking()) { // See whether the lock is currently biased toward our thread and // whether the epoch is still valid. // Note that the runtime guarantees sufficient alignment of JavaThread // pointers to allow age to be placed into low bits. final Word biasableLockBits = mark.and(biasedLockMaskInPlace()); // Check whether the bias pattern is present in the object's mark word // and the bias owner and the epoch are both still current. final Word prototypeMarkWord = hub.readWord(prototypeMarkWordOffset(), PROTOTYPE_MARK_WORD_LOCATION); final Word thread = registerAsWord(threadRegister); final Word tmp = prototypeMarkWord.or(thread).xor(mark).and(~ageMaskInPlace()); trace(trace, "prototypeMarkWord: 0x%016lx\n", prototypeMarkWord); trace(trace, " thread: 0x%016lx\n", thread); trace(trace, " tmp: 0x%016lx\n", tmp); if (probability(BranchProbabilityNode.NOT_LIKELY_PROBABILITY, tmp.equal(0))) { // Object is already biased to current thread -> done traceObject(trace, "+lock{bias:existing}", object, true); lockBiasExisting.inc(); FastAcquireBiasedLockNode.mark(object); return; } // Now check to see whether biasing is enabled for this object if (probability(BranchProbabilityNode.FAST_PATH_PROBABILITY, biasableLockBits.notEqual(Word.unsigned(biasedLockPattern())))) { // Biasing not enabled -> fall through to lightweight locking unbiasable.inc(); } else { // At this point we know that the mark word has the bias pattern and // that we are not the bias owner in the current epoch. We need to // figure out more details about the state of the mark word in order to // know what operations can be legally performed on the object's // mark word. // If the low three bits in the xor result aren't clear, that means // the prototype header is no longer biasable and we have to revoke // the bias on this object. if (probability(FREQUENT_PROBABILITY, tmp.and(biasedLockMaskInPlace()).equal(0))) { // Biasing is still enabled for object's type. See whether the // epoch of the current bias is still valid, meaning that the epoch // bits of the mark word are equal to the epoch bits of the // prototype mark word. (Note that the prototype mark word's epoch bits // only change at a safepoint.) If not, attempt to rebias the object // toward the current thread. Note that we must be absolutely sure // that the current epoch is invalid in order to do this because // otherwise the manipulations it performs on the mark word are // illegal. if (probability(FREQUENT_PROBABILITY, tmp.and(epochMaskInPlace()).equal(0))) { // The epoch of the current bias is still valid but we know nothing // about the owner; it might be set or it might be clear. Try to // acquire the bias of the object using an atomic operation. If this // fails we will go in to the runtime to revoke the object's bias. // Note that we first construct the presumed unbiased header so we // don't accidentally blow away another thread's valid bias. Word unbiasedMark = mark.and(biasedLockMaskInPlace() | ageMaskInPlace() | epochMaskInPlace()); Word biasedMark = unbiasedMark.or(thread); trace(trace, " unbiasedMark: 0x%016lx\n", unbiasedMark); trace(trace, " biasedMark: 0x%016lx\n", biasedMark); if (probability(VERY_FAST_PATH_PROBABILITY, compareAndSwap(OffsetAddressNode.address(object, markOffset()), unbiasedMark, biasedMark, MARK_WORD_LOCATION).equal(unbiasedMark))) { // Object is now biased to current thread -> done traceObject(trace, "+lock{bias:acquired}", object, true); lockBiasAcquired.inc(); return; } // If the biasing toward our thread failed, this means that another thread // owns the bias and we need to revoke that bias. The revocation will occur // in the interpreter runtime. traceObject(trace, "+lock{stub:revoke}", object, true); lockStubRevoke.inc(); } else { // At this point we know the epoch has expired, meaning that the // current bias owner, if any, is actually invalid. Under these // circumstances _only_, are we allowed to use the current mark word // value as the comparison value when doing the CAS to acquire the // bias in the current epoch. In other words, we allow transfer of // the bias from one thread to another directly in this situation. Word biasedMark = prototypeMarkWord.or(thread); trace(trace, " biasedMark: 0x%016lx\n", biasedMark); if (probability(VERY_FAST_PATH_PROBABILITY, compareAndSwap(OffsetAddressNode.address(object, markOffset()), mark, biasedMark, MARK_WORD_LOCATION).equal(mark))) { // Object is now biased to current thread -> done traceObject(trace, "+lock{bias:transfer}", object, true); lockBiasTransfer.inc(); return; } // If the biasing toward our thread failed, then another thread // succeeded in biasing it toward itself and we need to revoke that // bias. The revocation will occur in the runtime in the slow case. traceObject(trace, "+lock{stub:epoch-expired}", object, true); lockStubEpochExpired.inc(); } monitorenterStubC(MONITORENTER, object, lock); return; } else { // The prototype mark word doesn't have the bias bit set any // more, indicating that objects of this data type are not supposed // to be biased any more. We are going to try to reset the mark of // this object to the prototype value and fall through to the // CAS-based locking scheme. Note that if our CAS fails, it means // that another thread raced us for the privilege of revoking the // bias of this particular object, so it's okay to continue in the // normal locking code. Word result = compareAndSwap(OffsetAddressNode.address(object, markOffset()), mark, prototypeMarkWord, MARK_WORD_LOCATION); // Fall through to the normal CAS-based lock, because no matter what // the result of the above CAS, some thread must have succeeded in // removing the bias bit from the object's header. if (ENABLE_BREAKPOINT) { bkpt(object, mark, tmp, result); } revokeBias.inc(); } } } // Create the unlocked mark word pattern Word unlockedMark = mark.or(unlockedMask()); trace(trace, " unlockedMark: 0x%016lx\n", unlockedMark); // Copy this unlocked mark word into the lock slot on the stack lock.writeWord(lockDisplacedMarkOffset(), unlockedMark, DISPLACED_MARK_WORD_LOCATION); // Test if the object's mark word is unlocked, and if so, store the // (address of) the lock slot into the object's mark word. Word currentMark = compareAndSwap(OffsetAddressNode.address(object, markOffset()), unlockedMark, lock, MARK_WORD_LOCATION); if (probability(BranchProbabilityNode.SLOW_PATH_PROBABILITY, currentMark.notEqual(unlockedMark))) { trace(trace, " currentMark: 0x%016lx\n", currentMark); // The mark word in the object header was not the same. // Either the object is locked by another thread or is already locked // by the current thread. The latter is true if the mark word // is a stack pointer into the current thread's stack, i.e.: // // 1) (currentMark & aligned_mask) == 0 // 2) rsp <= currentMark // 3) currentMark <= rsp + page_size // // These 3 tests can be done by evaluating the following expression: // // (currentMark - rsp) & (aligned_mask - page_size) // // assuming both the stack pointer and page_size have their least // significant 2 bits cleared and page_size is a power of 2 final Word alignedMask = Word.unsigned(wordSize() - 1); final Word stackPointer = registerAsWord(stackPointerRegister).add(config().stackBias); if (probability(VERY_SLOW_PATH_PROBABILITY, currentMark.subtract(stackPointer).and(alignedMask.subtract(pageSize())).notEqual(0))) { // Most likely not a recursive lock, go into a slow runtime call traceObject(trace, "+lock{stub:failed-cas}", object, true); lockStubFailedCas.inc(); monitorenterStubC(MONITORENTER, object, lock); return; } else { // Recursively locked => write 0 to the lock slot lock.writeWord(lockDisplacedMarkOffset(), Word.zero(), DISPLACED_MARK_WORD_LOCATION); traceObject(trace, "+lock{cas:recursive}", object, true); lockCasRecursive.inc(); } } else { traceObject(trace, "+lock{cas}", object, true); lockCas.inc(); } } /** * Calls straight out to the monitorenter stub. */ @Snippet public static void monitorenterStub(Object object, @ConstantParameter int lockDepth, @ConstantParameter boolean trace) { verifyOop(object); incCounter(); if (object == null) { DeoptimizeNode.deopt(DeoptimizationAction.InvalidateReprofile, DeoptimizationReason.NullCheckException); } // BeginLockScope nodes do not read from object so a use of object // cannot float about the null check above final Word lock = beginLockScope(lockDepth); traceObject(trace, "+lock{stub}", object, true); monitorenterStubC(MONITORENTER, object, lock); } @Snippet public static void monitorexit(Object object, @ConstantParameter int lockDepth, @ConstantParameter boolean trace) { trace(trace, " object: 0x%016lx\n", Word.objectToTrackedPointer(object)); if (useBiasedLocking()) { // Check for biased locking unlock case, which is a no-op // Note: we do not have to check the thread ID for two reasons. // First, the interpreter checks for IllegalMonitorStateException at // a higher level. Second, if the bias was revoked while we held the // lock, the object could not be rebiased toward another thread, so // the bias bit would be clear. final Word mark = loadWordFromObject(object, markOffset()); trace(trace, " mark: 0x%016lx\n", mark); if (probability(BranchProbabilityNode.NOT_LIKELY_PROBABILITY, mark.and(biasedLockMaskInPlace()).equal(Word.unsigned(biasedLockPattern())))) { endLockScope(); decCounter(); traceObject(trace, "-lock{bias}", object, false); unlockBias.inc(); return; } } final Word lock = CurrentLockNode.currentLock(lockDepth); // Load displaced mark final Word displacedMark = lock.readWord(lockDisplacedMarkOffset(), DISPLACED_MARK_WORD_LOCATION); trace(trace, " displacedMark: 0x%016lx\n", displacedMark); if (probability(BranchProbabilityNode.NOT_LIKELY_PROBABILITY, displacedMark.equal(0))) { // Recursive locking => done traceObject(trace, "-lock{recursive}", object, false); unlockCasRecursive.inc(); } else { verifyOop(object); // Test if object's mark word is pointing to the displaced mark word, and if so, restore // the displaced mark in the object - if the object's mark word is not pointing to // the displaced mark word, do unlocking via runtime call. if (probability(VERY_SLOW_PATH_PROBABILITY, DirectCompareAndSwapNode.compareAndSwap(OffsetAddressNode.address(object, markOffset()), lock, displacedMark, MARK_WORD_LOCATION).notEqual(lock))) { // The object's mark word was not pointing to the displaced header, // we do unlocking via runtime call. traceObject(trace, "-lock{stub}", object, false); unlockStub.inc(); monitorexitStubC(MONITOREXIT, object, lock); } else { traceObject(trace, "-lock{cas}", object, false); unlockCas.inc(); } } endLockScope(); decCounter(); } /** * Calls straight out to the monitorexit stub. */ @Snippet public static void monitorexitStub(Object object, @ConstantParameter int lockDepth, @ConstantParameter boolean trace) { verifyOop(object); traceObject(trace, "-lock{stub}", object, false); final Word lock = CurrentLockNode.currentLock(lockDepth); monitorexitStubC(MONITOREXIT, object, lock); endLockScope(); decCounter(); } public static void traceObject(boolean enabled, String action, Object object, boolean enter) { if (doProfile()) { DynamicCounterNode.counter(action, enter ? "number of monitor enters" : "number of monitor exits", 1, PROFILE_CONTEXT); } if (enabled) { Log.print(action); Log.print(' '); Log.printlnObject(object); } } public static void trace(boolean enabled, String format, WordBase value) { if (enabled) { Log.printf(format, value.rawValue()); } } /** * Leaving the breakpoint code in to provide an example of how to use the {@link BreakpointNode} * intrinsic. */ private static final boolean ENABLE_BREAKPOINT = false; private static final LocationIdentity MONITOR_COUNTER_LOCATION = NamedLocationIdentity.mutable("MonitorCounter"); @NodeIntrinsic(BreakpointNode.class) static native void bkpt(Object object, Word mark, Word tmp, Word value); public static void incCounter() { if (CHECK_BALANCED_MONITORS) { final Word counter = MonitorCounterNode.counter(); final int count = counter.readInt(0, MONITOR_COUNTER_LOCATION); counter.writeInt(0, count + 1, MONITOR_COUNTER_LOCATION); } } public static void decCounter() { if (CHECK_BALANCED_MONITORS) { final Word counter = MonitorCounterNode.counter(); final int count = counter.readInt(0, MONITOR_COUNTER_LOCATION); counter.writeInt(0, count - 1, MONITOR_COUNTER_LOCATION); } } @Snippet private static void initCounter() { final Word counter = MonitorCounterNode.counter(); counter.writeInt(0, 0, MONITOR_COUNTER_LOCATION); } @Snippet private static void checkCounter(@ConstantParameter String errMsg) { final Word counter = MonitorCounterNode.counter(); final int count = counter.readInt(0, MONITOR_COUNTER_LOCATION); if (count != 0) { vmError(errMsg, count); } } public static class Templates extends AbstractTemplates { private final SnippetInfo monitorenter = snippet(MonitorSnippets.class, "monitorenter"); private final SnippetInfo monitorexit = snippet(MonitorSnippets.class, "monitorexit"); private final SnippetInfo monitorenterStub = snippet(MonitorSnippets.class, "monitorenterStub"); private final SnippetInfo monitorexitStub = snippet(MonitorSnippets.class, "monitorexitStub"); private final SnippetInfo initCounter = snippet(MonitorSnippets.class, "initCounter"); private final SnippetInfo checkCounter = snippet(MonitorSnippets.class, "checkCounter"); private final boolean useFastLocking; public Templates(HotSpotProviders providers, TargetDescription target, boolean useFastLocking) { super(providers, providers.getSnippetReflection(), target); this.useFastLocking = useFastLocking; } public void lower(RawMonitorEnterNode monitorenterNode, HotSpotRegistersProvider registers, LoweringTool tool) { StructuredGraph graph = monitorenterNode.graph(); checkBalancedMonitors(graph, tool); assert ((ObjectStamp) monitorenterNode.object().stamp()).nonNull(); Arguments args; if (useFastLocking) { args = new Arguments(monitorenter, graph.getGuardsStage(), tool.getLoweringStage()); } else { args = new Arguments(monitorenterStub, graph.getGuardsStage(), tool.getLoweringStage()); } args.add("object", monitorenterNode.object()); args.add("hub", monitorenterNode.getHub()); args.addConst("lockDepth", monitorenterNode.getMonitorId().getLockDepth()); args.addConst("threadRegister", registers.getThreadRegister()); args.addConst("stackPointerRegister", registers.getStackPointerRegister()); args.addConst("trace", isTracingEnabledForType(monitorenterNode.object()) || isTracingEnabledForMethod(graph.method())); template(args).instantiate(providers.getMetaAccess(), monitorenterNode, DEFAULT_REPLACER, args); } public void lower(MonitorExitNode monitorexitNode, LoweringTool tool) { StructuredGraph graph = monitorexitNode.graph(); Arguments args; if (useFastLocking) { args = new Arguments(monitorexit, graph.getGuardsStage(), tool.getLoweringStage()); } else { args = new Arguments(monitorexitStub, graph.getGuardsStage(), tool.getLoweringStage()); } args.add("object", monitorexitNode.object()); args.addConst("lockDepth", monitorexitNode.getMonitorId().getLockDepth()); args.addConst("trace", isTracingEnabledForType(monitorexitNode.object()) || isTracingEnabledForMethod(graph.method())); template(args).instantiate(providers.getMetaAccess(), monitorexitNode, DEFAULT_REPLACER, args); } public static boolean isTracingEnabledForType(ValueNode object) { ResolvedJavaType type = StampTool.typeOrNull(object.stamp()); if (TRACE_TYPE_FILTER == null) { return false; } else { if (TRACE_TYPE_FILTER.length() == 0) { return true; } if (type == null) { return false; } return (type.getName().contains(TRACE_TYPE_FILTER)); } } public static boolean isTracingEnabledForMethod(ResolvedJavaMethod method) { if (TRACE_METHOD_FILTER == null) { return false; } else { if (TRACE_METHOD_FILTER.length() == 0) { return true; } if (method == null) { return false; } return (method.format("%H.%n").contains(TRACE_METHOD_FILTER)); } } /** * If balanced monitor checking is enabled then nodes are inserted at the start and all * return points of the graph to initialize and check the monitor counter respectively. */ private void checkBalancedMonitors(StructuredGraph graph, LoweringTool tool) { if (CHECK_BALANCED_MONITORS) { NodeIterable<MonitorCounterNode> nodes = graph.getNodes().filter(MonitorCounterNode.class); if (nodes.isEmpty()) { // Only insert the nodes if this is the first monitorenter being lowered. JavaType returnType = initCounter.getMethod().getSignature().getReturnType(initCounter.getMethod().getDeclaringClass()); MethodCallTargetNode callTarget = graph.add(new MethodCallTargetNode(InvokeKind.Static, initCounter.getMethod(), new ValueNode[0], returnType, null)); InvokeNode invoke = graph.add(new InvokeNode(callTarget, 0)); invoke.setStateAfter(graph.start().stateAfter()); graph.addAfterFixed(graph.start(), invoke); StructuredGraph inlineeGraph = providers.getReplacements().getSnippet(initCounter.getMethod(), null); InliningUtil.inline(invoke, inlineeGraph, false, null); List<ReturnNode> rets = graph.getNodes(ReturnNode.TYPE).snapshot(); for (ReturnNode ret : rets) { returnType = checkCounter.getMethod().getSignature().getReturnType(checkCounter.getMethod().getDeclaringClass()); String msg = "unbalanced monitors in " + graph.method().format("%H.%n(%p)") + ", count = %d"; ConstantNode errMsg = ConstantNode.forConstant(tool.getConstantReflection().forString(msg), providers.getMetaAccess(), graph); callTarget = graph.add(new MethodCallTargetNode(InvokeKind.Static, checkCounter.getMethod(), new ValueNode[]{errMsg}, returnType, null)); invoke = graph.add(new InvokeNode(callTarget, 0)); FrameState stateAfter = new FrameState(null, graph.method(), BytecodeFrame.AFTER_BCI, new ValueNode[0], new ValueNode[0], 0, new ValueNode[0], null, false, false); invoke.setStateAfter(graph.add(stateAfter)); graph.addBeforeFixed(ret, invoke); Arguments args = new Arguments(checkCounter, graph.getGuardsStage(), tool.getLoweringStage()); args.addConst("errMsg", msg); inlineeGraph = template(args).copySpecializedGraph(); // inlineeGraph = replacements.getSnippet(checkCounter.getMethod()); InliningUtil.inline(invoke, inlineeGraph, false, null); } } } } } public static final ForeignCallDescriptor MONITORENTER = new ForeignCallDescriptor("monitorenter", void.class, Object.class, Word.class); public static final ForeignCallDescriptor MONITOREXIT = new ForeignCallDescriptor("monitorexit", void.class, Object.class, Word.class); @NodeIntrinsic(ForeignCallNode.class) private static native void monitorenterStubC(@ConstantNodeParameter ForeignCallDescriptor descriptor, Object object, Word lock); @NodeIntrinsic(ForeignCallNode.class) private static native void monitorexitStubC(@ConstantNodeParameter ForeignCallDescriptor descriptor, Object object, Word lock); /** * Counters for the various paths for acquiring a lock. The counters whose names start with * {@code "lock"} are mutually exclusive. The other counters are for paths that may be shared. */ public static final SnippetCounter.Group lockCounters = SnippetCounters.getValue() ? new SnippetCounter.Group("MonitorEnters") : null; public static final SnippetCounter lockBiasExisting = new SnippetCounter(lockCounters, "lock{bias:existing}", "bias-locked previously biased object"); public static final SnippetCounter lockBiasAcquired = new SnippetCounter(lockCounters, "lock{bias:acquired}", "bias-locked newly biased object"); public static final SnippetCounter lockBiasTransfer = new SnippetCounter(lockCounters, "lock{bias:transfer}", "bias-locked, biased transferred"); public static final SnippetCounter lockCas = new SnippetCounter(lockCounters, "lock{cas}", "cas-locked an object"); public static final SnippetCounter lockCasRecursive = new SnippetCounter(lockCounters, "lock{cas:recursive}", "cas-locked, recursive"); public static final SnippetCounter lockStubEpochExpired = new SnippetCounter(lockCounters, "lock{stub:epoch-expired}", "stub-locked, epoch expired"); public static final SnippetCounter lockStubRevoke = new SnippetCounter(lockCounters, "lock{stub:revoke}", "stub-locked, biased revoked"); public static final SnippetCounter lockStubFailedCas = new SnippetCounter(lockCounters, "lock{stub:failed-cas}", "stub-locked, failed cas"); public static final SnippetCounter unbiasable = new SnippetCounter(lockCounters, "unbiasable", "object with unbiasable type"); public static final SnippetCounter revokeBias = new SnippetCounter(lockCounters, "revokeBias", "object had bias revoked"); /** * Counters for the various paths for releasing a lock. The counters whose names start with * {@code "unlock"} are mutually exclusive. The other counters are for paths that may be shared. */ public static final SnippetCounter.Group unlockCounters = SnippetCounters.getValue() ? new SnippetCounter.Group("MonitorExits") : null; public static final SnippetCounter unlockBias = new SnippetCounter(unlockCounters, "unlock{bias}", "bias-unlocked an object"); public static final SnippetCounter unlockCas = new SnippetCounter(unlockCounters, "unlock{cas}", "cas-unlocked an object"); public static final SnippetCounter unlockCasRecursive = new SnippetCounter(unlockCounters, "unlock{cas:recursive}", "cas-unlocked an object, recursive"); public static final SnippetCounter unlockStub = new SnippetCounter(unlockCounters, "unlock{stub}", "stub-unlocked an object"); }