1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
|
/*
* Copyright (C) 2013, 2014 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 "CodeBlockSet.h"
#include "CodeBlock.h"
#include "JSCInlines.h"
#include "SlotVisitor.h"
#include <wtf/CommaPrinter.h>
namespace JSC {
static const bool verbose = false;
CodeBlockSet::CodeBlockSet(BlockAllocator& blockAllocator)
: m_currentlyExecuting(blockAllocator)
{
}
CodeBlockSet::~CodeBlockSet()
{
for (CodeBlock* codeBlock : m_oldCodeBlocks)
codeBlock->deref();
for (CodeBlock* codeBlock : m_newCodeBlocks)
codeBlock->deref();
}
void CodeBlockSet::add(PassRefPtr<CodeBlock> codeBlock)
{
CodeBlock* block = codeBlock.leakRef();
bool isNewEntry = m_newCodeBlocks.add(block).isNewEntry;
ASSERT_UNUSED(isNewEntry, isNewEntry);
}
void CodeBlockSet::promoteYoungCodeBlocks()
{
m_oldCodeBlocks.add(m_newCodeBlocks.begin(), m_newCodeBlocks.end());
m_newCodeBlocks.clear();
}
void CodeBlockSet::clearMarksForFullCollection()
{
for (CodeBlock* codeBlock : m_oldCodeBlocks) {
codeBlock->m_mayBeExecuting = false;
codeBlock->m_visitAggregateHasBeenCalled = false;
}
// We promote after we clear marks on the old generation CodeBlocks because
// none of the young generations CodeBlocks need to be cleared.
promoteYoungCodeBlocks();
}
void CodeBlockSet::clearMarksForEdenCollection(const Vector<const JSCell*>& rememberedSet)
{
// This ensures that we will revisit CodeBlocks in remembered Executables even if they were previously marked.
for (const JSCell* cell : rememberedSet) {
ScriptExecutable* executable = const_cast<ScriptExecutable*>(jsDynamicCast<const ScriptExecutable*>(cell));
if (!executable)
continue;
executable->forEachCodeBlock([](CodeBlock* codeBlock) {
codeBlock->m_mayBeExecuting = false;
codeBlock->m_visitAggregateHasBeenCalled = false;
});
}
}
void CodeBlockSet::deleteUnmarkedAndUnreferenced(HeapOperation collectionType)
{
HashSet<CodeBlock*>& set = collectionType == EdenCollection ? m_newCodeBlocks : m_oldCodeBlocks;
// This needs to be a fixpoint because code blocks that are unmarked may
// refer to each other. For example, a DFG code block that is owned by
// the GC may refer to an FTL for-entry code block that is also owned by
// the GC.
Vector<CodeBlock*, 16> toRemove;
if (verbose)
dataLog("Fixpointing over unmarked, set size = ", set.size(), "...\n");
for (;;) {
for (CodeBlock* codeBlock : set) {
if (!codeBlock->hasOneRef())
continue;
if (codeBlock->m_mayBeExecuting)
continue;
codeBlock->deref();
toRemove.append(codeBlock);
}
if (verbose)
dataLog(" Removing ", toRemove.size(), " blocks.\n");
if (toRemove.isEmpty())
break;
for (CodeBlock* codeBlock : toRemove)
set.remove(codeBlock);
toRemove.resize(0);
}
// Any remaining young CodeBlocks are live and need to be promoted to the set of old CodeBlocks.
if (collectionType == EdenCollection)
promoteYoungCodeBlocks();
}
void CodeBlockSet::remove(CodeBlock* codeBlock)
{
codeBlock->deref();
if (m_oldCodeBlocks.contains(codeBlock)) {
m_oldCodeBlocks.remove(codeBlock);
return;
}
ASSERT(m_newCodeBlocks.contains(codeBlock));
m_newCodeBlocks.remove(codeBlock);
}
void CodeBlockSet::traceMarked(SlotVisitor& visitor)
{
if (verbose)
dataLog("Tracing ", m_currentlyExecuting.size(), " code blocks.\n");
for (CodeBlock* codeBlock : m_currentlyExecuting) {
ASSERT(codeBlock->m_mayBeExecuting);
codeBlock->visitAggregate(visitor);
}
}
void CodeBlockSet::rememberCurrentlyExecutingCodeBlocks(Heap* heap)
{
#if ENABLE(GGC)
if (verbose)
dataLog("Remembering ", m_currentlyExecuting.size(), " code blocks.\n");
for (CodeBlock* codeBlock : m_currentlyExecuting) {
heap->addToRememberedSet(codeBlock->ownerExecutable());
ASSERT(codeBlock->m_mayBeExecuting);
}
m_currentlyExecuting.clear();
#else
UNUSED_PARAM(heap);
#endif // ENABLE(GGC)
}
void CodeBlockSet::dump(PrintStream& out) const
{
CommaPrinter comma;
out.print("{old = [");
for (CodeBlock* codeBlock : m_oldCodeBlocks)
out.print(comma, pointerDump(codeBlock));
out.print("], new = [");
comma = CommaPrinter();
for (CodeBlock* codeBlock : m_newCodeBlocks)
out.print(comma, pointerDump(codeBlock));
out.print("], currentlyExecuting = [");
comma = CommaPrinter();
for (CodeBlock* codeBlock : m_currentlyExecuting)
out.print(comma, pointerDump(codeBlock));
out.print("]}");
}
} // namespace JSC
|
