heap/GCThreadSharedData.h

   1 /*
   2  * Copyright (C) 2009, 2011 Apple Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #ifndef GCThreadSharedData_h
  27 #define GCThreadSharedData_h
  28
  29 #include "ListableHandler.h"
  30 #include "MarkStack.h"
  31 #include "MarkedBlock.h"
  32 #include "UnconditionalFinalizer.h"
  33 #include "WeakReferenceHarvester.h"
  34 #include <condition_variable>
  35 #include <wtf/HashSet.h>
  36 #include <wtf/SpinLock.h>
  37 #include <wtf/Vector.h>
  38
  39 namespace JSC {
  40
  41 class CopiedBlock;
  42 class CopiedSpace;
  43 class CopyVisitor;
  44 class GCThread;
  45 class VM;
  46
  47 enum GCPhase {
  48     NoPhase,
  49     Mark,
  50     Copy,
  51     Exit
  52 };
  53
  54 class GCThreadSharedData {
  55     WTF_MAKE_FAST_ALLOCATED;
  56 public:
  57     GCThreadSharedData(VM*);
  58     ~GCThreadSharedData();
  59
  60     void reset();
  61
  62     void didStartMarking();
  63     void didFinishMarking();
  64     void didStartCopying();
  65     void didFinishCopying();
  66
  67 #if ENABLE(PARALLEL_GC)
  68     void resetChildren();
  69     size_t childVisitCount();
  70     size_t childBytesVisited();
  71     size_t childBytesCopied();
  72     size_t childDupStrings();
  73 #endif
  74
  75 private:
  76     friend class GCThread;
  77     friend class SlotVisitor;
  78     friend class CopyVisitor;
  79
  80     void getNextBlocksToCopy(size_t&, size_t&);
  81     void startNextPhase(GCPhase);
  82     void endCurrentPhase();
  83
  84     VM* m_vm;
  85     CopiedSpace* m_copiedSpace;
  86
  87     bool m_shouldHashCons;
  88
  89     Vector<GCThread*> m_gcThreads;
  90
  91     std::mutex m_markingMutex;
  92     std::condition_variable m_markingConditionVariable;
  93     MarkStackArray m_sharedMarkStack;
  94     unsigned m_numberOfActiveParallelMarkers;
  95     bool m_parallelMarkersShouldExit;
  96
  97     std::mutex m_opaqueRootsMutex;
  98     HashSet<void*> m_opaqueRoots;
  99
 100     SpinLock m_copyLock;
 101     Vector<CopiedBlock*> m_blocksToCopy;
 102     size_t m_copyIndex;
 103     static const size_t s_blockFragmentLength = 32;
 104
 105     std::mutex m_phaseMutex;
 106     std::condition_variable m_phaseConditionVariable;
 107     std::condition_variable m_activityConditionVariable;
 108     unsigned m_numberOfActiveGCThreads;
 109     bool m_gcThreadsShouldWait;
 110     GCPhase m_currentPhase;
 111
 112     ListableHandler<WeakReferenceHarvester>::List m_weakReferenceHarvesters;
 113     ListableHandler<UnconditionalFinalizer>::List m_unconditionalFinalizers;
 114 };
 115
 116 inline void GCThreadSharedData::getNextBlocksToCopy(size_t& start, size_t& end)
 117 {
 118     SpinLockHolder locker(&m_copyLock);
 119     start = m_copyIndex;
 120     end = std::min(m_blocksToCopy.size(), m_copyIndex + s_blockFragmentLength);
 121     m_copyIndex = end;
 122 }
 123
 124 } // namespace JSC
 125
 126 #endif