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
38namespace JSC {
39
40#if USE(CF) || PLATFORM(BLACKBERRY) || PLATFORM(QT)
41
42static const double sweepTimeSlice = .01; // seconds
43static const double sweepTimeTotal = .10;
44static const double sweepTimeMultiplier = 1.0 / sweepTimeTotal;
45
46#if USE(CF)
47
48IncrementalSweeper::IncrementalSweeper(Heap* heap, CFRunLoopRef runLoop)
49    : HeapTimer(heap->vm(), runLoop)
50    , m_currentBlockToSweepIndex(0)
51    , m_blocksToSweep(heap->m_blockSnapshot)
52{
53}
54
55PassOwnPtr<IncrementalSweeper> IncrementalSweeper::create(Heap* heap)
56{
57    return adoptPtr(new IncrementalSweeper(heap, CFRunLoopGetCurrent()));
58}
59
60void IncrementalSweeper::scheduleTimer()
61{
62    CFRunLoopTimerSetNextFireDate(m_timer.get(), CFAbsoluteTimeGetCurrent() + (sweepTimeSlice * sweepTimeMultiplier));
63}
64
65void IncrementalSweeper::cancelTimer()
66{
67    CFRunLoopTimerSetNextFireDate(m_timer.get(), CFAbsoluteTimeGetCurrent() + s_decade);
68}
69
70#elif PLATFORM(BLACKBERRY) || PLATFORM(QT)
71
72IncrementalSweeper::IncrementalSweeper(Heap* heap)
73    : HeapTimer(heap->vm())
74    , m_currentBlockToSweepIndex(0)
75    , m_blocksToSweep(heap->m_blockSnapshot)
76{
77}
78
79PassOwnPtr<IncrementalSweeper> IncrementalSweeper::create(Heap* heap)
80{
81    return adoptPtr(new IncrementalSweeper(heap));
82}
83
84void 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
93void IncrementalSweeper::cancelTimer()
94{
95    m_timer.stop();
96}
97
98#endif
99
100void IncrementalSweeper::doWork()
101{
102    doSweep(WTF::monotonicallyIncreasingTime());
103}
104
105void 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
122void 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
136void IncrementalSweeper::startSweeping(Vector<MarkedBlock*>& blockSnapshot)
137{
138    m_blocksToSweep = blockSnapshot;
139    m_currentBlockToSweepIndex = 0;
140    scheduleTimer();
141}
142
143void IncrementalSweeper::willFinishSweeping()
144{
145    m_currentBlockToSweepIndex = 0;
146    m_blocksToSweep.clear();
147    if (m_vm)
148        cancelTimer();
149}
150
151#else
152
153IncrementalSweeper::IncrementalSweeper(VM* vm)
154    : HeapTimer(vm)
155{
156}
157
158void IncrementalSweeper::doWork()
159{
160}
161
162PassOwnPtr<IncrementalSweeper> IncrementalSweeper::create(Heap* heap)
163{
164    return adoptPtr(new IncrementalSweeper(heap->vm()));
165}
166
167void IncrementalSweeper::startSweeping(Vector<MarkedBlock*>&)
168{
169}
170
171void IncrementalSweeper::willFinishSweeping()
172{
173}
174
175void IncrementalSweeper::sweepNextBlock()
176{
177}
178
179#endif
180
181} // namespace JSC
182