JavaScriptCore-1218.tar.gz

[apple/javascriptcore.git] / heap / GCThreadSharedData.cpp

diff --git a/heap/GCThreadSharedData.cpp b/heap/GCThreadSharedData.cpp
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+/*
+ * Copyright (C) 2009, 2011 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#include "config.h"
+#include "GCThreadSharedData.h"
+
+#include "CopyVisitor.h"
+#include "CopyVisitorInlines.h"
+#include "GCThread.h"
+#include "VM.h"
+#include "MarkStack.h"
+#include "SlotVisitor.h"
+#include "SlotVisitorInlines.h"
+
+namespace JSC {
+
+#if ENABLE(PARALLEL_GC)
+void GCThreadSharedData::resetChildren()
+{
+    for (size_t i = 0; i < m_gcThreads.size(); ++i)
+        m_gcThreads[i]->slotVisitor()->reset();
+}
+
+size_t GCThreadSharedData::childVisitCount()
+{       
+    unsigned long result = 0;
+    for (unsigned i = 0; i < m_gcThreads.size(); ++i)
+        result += m_gcThreads[i]->slotVisitor()->visitCount();
+    return result;
+}
+#endif
+
+GCThreadSharedData::GCThreadSharedData(VM* vm)
+    : m_vm(vm)
+    , m_copiedSpace(&vm->heap.m_storageSpace)
+    , m_shouldHashCons(false)
+    , m_sharedMarkStack(vm->heap.blockAllocator())
+    , m_numberOfActiveParallelMarkers(0)
+    , m_parallelMarkersShouldExit(false)
+    , m_copyIndex(0)
+    , m_numberOfActiveGCThreads(0)
+    , m_gcThreadsShouldWait(false)
+    , m_currentPhase(NoPhase)
+{
+    m_copyLock.Init();
+#if ENABLE(PARALLEL_GC)
+    // Grab the lock so the new GC threads can be properly initialized before they start running.
+    MutexLocker locker(m_phaseLock);
+    for (unsigned i = 1; i < Options::numberOfGCMarkers(); ++i) {
+        m_numberOfActiveGCThreads++;
+        SlotVisitor* slotVisitor = new SlotVisitor(*this);
+        CopyVisitor* copyVisitor = new CopyVisitor(*this);
+        GCThread* newThread = new GCThread(*this, slotVisitor, copyVisitor);
+        ThreadIdentifier threadID = createThread(GCThread::gcThreadStartFunc, newThread, "JavaScriptCore::Marking");
+        newThread->initializeThreadID(threadID);
+        m_gcThreads.append(newThread);
+    }
+
+    // Wait for all the GCThreads to get to the right place.
+    while (m_numberOfActiveGCThreads)
+        m_activityCondition.wait(m_phaseLock);
+#endif
+}
+
+GCThreadSharedData::~GCThreadSharedData()
+{
+#if ENABLE(PARALLEL_GC)    
+    // Destroy our marking threads.
+    {
+        MutexLocker markingLocker(m_markingLock);
+        MutexLocker phaseLocker(m_phaseLock);
+        ASSERT(m_currentPhase == NoPhase);
+        m_parallelMarkersShouldExit = true;
+        m_gcThreadsShouldWait = false;
+        m_currentPhase = Exit;
+        m_phaseCondition.broadcast();
+    }
+    for (unsigned i = 0; i < m_gcThreads.size(); ++i) {
+        waitForThreadCompletion(m_gcThreads[i]->threadID());
+        delete m_gcThreads[i];
+    }
+#endif
+}
+    
+void GCThreadSharedData::reset()
+{
+    ASSERT(m_sharedMarkStack.isEmpty());
+    
+#if ENABLE(PARALLEL_GC)
+    m_opaqueRoots.clear();
+#else
+    ASSERT(m_opaqueRoots.isEmpty());
+#endif
+    m_weakReferenceHarvesters.removeAll();
+
+    if (m_shouldHashCons) {
+        m_vm->resetNewStringsSinceLastHashCons();
+        m_shouldHashCons = false;
+    }
+}
+
+void GCThreadSharedData::startNextPhase(GCPhase phase)
+{
+    MutexLocker phaseLocker(m_phaseLock);
+    ASSERT(!m_gcThreadsShouldWait);
+    ASSERT(m_currentPhase == NoPhase);
+    m_gcThreadsShouldWait = true;
+    m_currentPhase = phase;
+    m_phaseCondition.broadcast();
+}
+
+void GCThreadSharedData::endCurrentPhase()
+{
+    ASSERT(m_gcThreadsShouldWait);
+    MutexLocker locker(m_phaseLock);
+    m_currentPhase = NoPhase;
+    m_gcThreadsShouldWait = false;
+    m_phaseCondition.broadcast();
+    while (m_numberOfActiveGCThreads)
+        m_activityCondition.wait(m_phaseLock);
+}
+
+void GCThreadSharedData::didStartMarking()
+{
+    MutexLocker markingLocker(m_markingLock);
+    m_parallelMarkersShouldExit = false;
+    startNextPhase(Mark);
+}
+
+void GCThreadSharedData::didFinishMarking()
+{
+    {
+        MutexLocker markingLocker(m_markingLock);
+        m_parallelMarkersShouldExit = true;
+        m_markingCondition.broadcast();
+    }
+
+    ASSERT(m_currentPhase == Mark);
+    endCurrentPhase();
+}
+
+void GCThreadSharedData::didStartCopying()
+{
+    {
+        SpinLockHolder locker(&m_copyLock);
+        WTF::copyToVector(m_copiedSpace->m_blockSet, m_blocksToCopy);
+        m_copyIndex = 0;
+    }
+
+    // We do this here so that we avoid a race condition where the main thread can 
+    // blow through all of the copying work before the GCThreads fully wake up. 
+    // The GCThreads then request a block from the CopiedSpace when the copying phase 
+    // has completed, which isn't allowed.
+    for (size_t i = 0; i < m_gcThreads.size(); i++)
+        m_gcThreads[i]->copyVisitor()->startCopying();
+
+    startNextPhase(Copy);
+}
+
+void GCThreadSharedData::didFinishCopying()
+{
+    ASSERT(m_currentPhase == Copy);
+    endCurrentPhase();
+}
+
+} // namespace JSC