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