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
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
|
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=8 sts=2 et sw=2 tw=80:
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "gc/WeakMap-inl.h"
#include <string.h>
#include "gc/PublicIterators.h"
#include "vm/JSObject.h"
#include "gc/Marking-inl.h"
using namespace js;
using namespace js::gc;
WeakMapBase::WeakMapBase(JSObject* memOf, Zone* zone)
: memberOf(memOf), zone_(zone) {
MOZ_ASSERT_IF(memberOf, memberOf->compartment()->zone() == zone);
MOZ_ASSERT(!IsMarked(mapColor()));
}
WeakMapBase::~WeakMapBase() {
MOZ_ASSERT(CurrentThreadIsGCFinalizing() ||
CurrentThreadCanAccessZone(zone_));
}
void WeakMapBase::unmarkZone(JS::Zone* zone) {
AutoEnterOOMUnsafeRegion oomUnsafe;
if (!zone->gcEphemeronEdges().clear()) {
oomUnsafe.crash("clearing ephemeron edges table");
}
MOZ_ASSERT(zone->gcNurseryEphemeronEdges().count() == 0);
for (WeakMapBase* m : zone->gcWeakMapList()) {
m->setMapColor(CellColor::White);
}
}
void Zone::traceWeakMaps(JSTracer* trc) {
MOZ_ASSERT(trc->weakMapAction() != JS::WeakMapTraceAction::Skip);
for (WeakMapBase* m : gcWeakMapList()) {
m->trace(trc);
TraceNullableEdge(trc, &m->memberOf, "memberOf");
}
}
bool WeakMapBase::markMap(MarkColor markColor) {
// We may be marking in parallel here so use a compare exchange loop to handle
// concurrent updates to the map color.
//
// The color increases monotonically; we don't downgrade from black to gray.
//
// We can attempt to mark gray after marking black when a barrier pushes the
// map object onto the black mark stack when it's already present on the
// gray mark stack, since this is marked later.
uint32_t targetColor = uint32_t(markColor);
for (;;) {
uint32_t currentColor = mapColor_;
if (currentColor >= targetColor) {
return false;
}
if (mapColor_.compareExchange(currentColor, targetColor)) {
return true;
}
}
}
bool WeakMapBase::addImplicitEdges(MarkColor mapColor, Cell* key,
Cell* delegate, TenuredCell* value) {
if (delegate) {
return addEphemeronTableEntries(mapColor, delegate, key, value);
}
if (value) {
return addEphemeronTableEntries(mapColor, key, value, nullptr);
}
return true;
}
bool WeakMapBase::addEphemeronTableEntries(MarkColor mapColor, gc::Cell* key,
gc::Cell* value1,
gc::Cell* maybeValue2) {
// Add implicit edges from |key| to |value1| and |maybeValue2| if supplied.
//
// Note the key and values do not necessarily correspond to the weak map
// entry's key and value at this point.
auto& edgeTable = key->zone()->gcEphemeronEdges(key);
auto* ptr = edgeTable.getOrAdd(key);
if (!ptr) {
return false;
}
if (!ptr->value.emplaceBack(mapColor, value1)) {
return false;
}
if (maybeValue2 && !ptr->value.emplaceBack(mapColor, maybeValue2)) {
return false;
}
return true;
}
#if defined(JS_GC_ZEAL) || defined(DEBUG)
bool WeakMapBase::checkMarkingForZone(JS::Zone* zone) {
// This is called at the end of marking.
MOZ_ASSERT(zone->isGCMarking());
bool ok = true;
for (WeakMapBase* m : zone->gcWeakMapList()) {
if (IsMarked(m->mapColor()) && !m->checkMarking()) {
ok = false;
}
}
return ok;
}
#endif
bool WeakMapBase::markZoneIteratively(JS::Zone* zone, GCMarker* marker) {
bool markedAny = false;
for (WeakMapBase* m : zone->gcWeakMapList()) {
if (IsMarked(m->mapColor()) && m->markEntries(marker)) {
markedAny = true;
}
}
return markedAny;
}
bool WeakMapBase::findSweepGroupEdgesForZone(JS::Zone* zone) {
for (WeakMapBase* m : zone->gcWeakMapList()) {
if (!m->findSweepGroupEdges()) {
return false;
}
}
return true;
}
void Zone::sweepWeakMaps(JSTracer* trc) {
for (WeakMapBase* m = gcWeakMapList().getFirst(); m;) {
WeakMapBase* next = m->getNext();
if (IsMarked(m->mapColor())) {
m->traceWeakEdges(trc);
} else {
m->clearAndCompact();
m->removeFrom(gcWeakMapList());
}
m = next;
}
#ifdef DEBUG
for (WeakMapBase* m : gcWeakMapList()) {
MOZ_ASSERT(m->isInList() && IsMarked(m->mapColor()));
}
#endif
}
void WeakMapBase::traceAllMappings(WeakMapTracer* tracer) {
JSRuntime* rt = tracer->runtime;
for (ZonesIter zone(rt, SkipAtoms); !zone.done(); zone.next()) {
for (WeakMapBase* m : zone->gcWeakMapList()) {
// The WeakMapTracer callback is not allowed to GC.
JS::AutoSuppressGCAnalysis nogc;
m->traceMappings(tracer);
}
}
}
bool WeakMapBase::saveZoneMarkedWeakMaps(JS::Zone* zone,
WeakMapColors& markedWeakMaps) {
for (WeakMapBase* m : zone->gcWeakMapList()) {
if (IsMarked(m->mapColor()) && !markedWeakMaps.put(m, m->mapColor())) {
return false;
}
}
return true;
}
void WeakMapBase::restoreMarkedWeakMaps(WeakMapColors& markedWeakMaps) {
for (WeakMapColors::Range r = markedWeakMaps.all(); !r.empty();
r.popFront()) {
WeakMapBase* map = r.front().key();
MOZ_ASSERT(map->zone()->isGCMarking());
MOZ_ASSERT(!IsMarked(map->mapColor()));
map->setMapColor(r.front().value());
}
}
ObjectWeakMap::ObjectWeakMap(JSContext* cx) : map(cx, nullptr) {}
JSObject* ObjectWeakMap::lookup(const JSObject* obj) {
if (ObjectValueWeakMap::Ptr p = map.lookup(const_cast<JSObject*>(obj))) {
return &p->value().toObject();
}
return nullptr;
}
bool ObjectWeakMap::add(JSContext* cx, JSObject* obj, JSObject* target) {
MOZ_ASSERT(obj && target);
Value targetVal(ObjectValue(*target));
if (!map.putNew(obj, targetVal)) {
ReportOutOfMemory(cx);
return false;
}
return true;
}
void ObjectWeakMap::remove(JSObject* key) {
MOZ_ASSERT(key);
map.remove(key);
}
void ObjectWeakMap::clear() { map.clear(); }
void ObjectWeakMap::trace(JSTracer* trc) { map.trace(trc); }
size_t ObjectWeakMap::sizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) {
return map.shallowSizeOfExcludingThis(mallocSizeOf);
}
#ifdef JSGC_HASH_TABLE_CHECKS
void ObjectWeakMap::checkAfterMovingGC() {
for (ObjectValueWeakMap::Range r = map.all(); !r.empty(); r.popFront()) {
CheckGCThingAfterMovingGC(r.front().key().get());
CheckGCThingAfterMovingGC(&r.front().value().toObject());
}
}
#endif // JSGC_HASH_TABLE_CHECKS
|
