heap/IncrementalSweeper.cpp

   1 /*
   2  * Copyright (C) 2012 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 #include "config.h"
  27 #include "IncrementalSweeper.h"
  28
  29 #include "APIShims.h"
  30 #include "Heap.h"
  31 #include "JSObject.h"
  32 #include "JSString.h"
  33 #include "MarkedBlock.h"
  34
  35 #include <wtf/HashSet.h>
  36 #include <wtf/WTFThreadData.h>
  37
  38 namespace JSC {
  39
  40 #if USE(CF) || PLATFORM(BLACKBERRY) || PLATFORM(QT)
  41
  42 static const double sweepTimeSlice = .01; // seconds
  43 static const double sweepTimeTotal = .10;
  44 static const double sweepTimeMultiplier = 1.0 / sweepTimeTotal;
  45
  46 #if USE(CF)
  47
  48 IncrementalSweeper::IncrementalSweeper(Heap* heap, CFRunLoopRef runLoop)
  49     : HeapTimer(heap->vm(), runLoop)
  50     , m_currentBlockToSweepIndex(0)
  51     , m_blocksToSweep(heap->m_blockSnapshot)
  52 {
  53 }
  54
  55 PassOwnPtr<IncrementalSweeper> IncrementalSweeper::create(Heap* heap)
  56 {
  57     return adoptPtr(new IncrementalSweeper(heap, CFRunLoopGetCurrent()));
  58 }
  59
  60 void IncrementalSweeper::scheduleTimer()
  61 {
  62     CFRunLoopTimerSetNextFireDate(m_timer.get(), CFAbsoluteTimeGetCurrent() + (sweepTimeSlice * sweepTimeMultiplier));
  63 }
  64
  65 void IncrementalSweeper::cancelTimer()
  66 {
  67     CFRunLoopTimerSetNextFireDate(m_timer.get(), CFAbsoluteTimeGetCurrent() + s_decade);
  68 }
  69
  70 #elif PLATFORM(BLACKBERRY) || PLATFORM(QT)
  71
  72 IncrementalSweeper::IncrementalSweeper(Heap* heap)
  73     : HeapTimer(heap->vm())
  74     , m_currentBlockToSweepIndex(0)
  75     , m_blocksToSweep(heap->m_blockSnapshot)
  76 {
  77 }
  78
  79 PassOwnPtr<IncrementalSweeper> IncrementalSweeper::create(Heap* heap)
  80 {
  81     return adoptPtr(new IncrementalSweeper(heap));
  82 }
  83
  84 void IncrementalSweeper::scheduleTimer()
  85 {
  86 #if PLATFORM(QT)
  87     m_timer.start(sweepTimeSlice * sweepTimeMultiplier * 1000, this);
  88 #else
  89     m_timer.start(sweepTimeSlice * sweepTimeMultiplier);
  90 #endif
  91 }
  92
  93 void IncrementalSweeper::cancelTimer()
  94 {
  95     m_timer.stop();
  96 }
  97
  98 #endif
  99
 100 void IncrementalSweeper::doWork()
 101 {
 102     doSweep(WTF::monotonicallyIncreasingTime());
 103 }
 104
 105 void IncrementalSweeper::doSweep(double sweepBeginTime)
 106 {
 107     while (m_currentBlockToSweepIndex < m_blocksToSweep.size()) {
 108         sweepNextBlock();
 109
 110         double elapsedTime = WTF::monotonicallyIncreasingTime() - sweepBeginTime;
 111         if (elapsedTime < sweepTimeSlice)
 112             continue;
 113
 114         scheduleTimer();
 115         return;
 116     }
 117
 118     m_blocksToSweep.clear();
 119     cancelTimer();
 120 }
 121
 122 void IncrementalSweeper::sweepNextBlock()
 123 {
 124     while (m_currentBlockToSweepIndex < m_blocksToSweep.size()) {
 125         MarkedBlock* block = m_blocksToSweep[m_currentBlockToSweepIndex++];
 126
 127         if (!block->needsSweeping())
 128             continue;
 129
 130         block->sweep();
 131         m_vm->heap.objectSpace().freeOrShrinkBlock(block);
 132         return;
 133     }
 134 }
 135
 136 void IncrementalSweeper::startSweeping(Vector<MarkedBlock*>& blockSnapshot)
 137 {
 138     m_blocksToSweep = blockSnapshot;
 139     m_currentBlockToSweepIndex = 0;
 140     scheduleTimer();
 141 }
 142
 143 void IncrementalSweeper::willFinishSweeping()
 144 {
 145     m_currentBlockToSweepIndex = 0;
 146     m_blocksToSweep.clear();
 147     if (m_vm)
 148         cancelTimer();
 149 }
 150
 151 #else
 152
 153 IncrementalSweeper::IncrementalSweeper(VM* vm)
 154     : HeapTimer(vm)
 155 {
 156 }
 157
 158 void IncrementalSweeper::doWork()
 159 {
 160 }
 161
 162 PassOwnPtr<IncrementalSweeper> IncrementalSweeper::create(Heap* heap)
 163 {
 164     return adoptPtr(new IncrementalSweeper(heap->vm()));
 165 }
 166
 167 void IncrementalSweeper::startSweeping(Vector<MarkedBlock*>&)
 168 {
 169 }
 170
 171 void IncrementalSweeper::willFinishSweeping()
 172 {
 173 }
 174
 175 void IncrementalSweeper::sweepNextBlock()
 176 {
 177 }
 178
 179 #endif
 180
 181 } // namespace JSC