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
|
/* -*- 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/. */
#ifndef jit_JitRealm_h
#define jit_JitRealm_h
#include "mozilla/Assertions.h"
#include "mozilla/Attributes.h"
#include "mozilla/EnumeratedArray.h"
#include "mozilla/MemoryReporting.h"
#include <stddef.h>
#include <stdint.h>
#include "gc/Barrier.h"
#include "gc/ZoneAllocator.h"
#include "js/GCHashTable.h"
#include "js/RootingAPI.h"
#include "js/TracingAPI.h"
#include "js/TypeDecls.h"
namespace js {
MOZ_COLD void ReportOutOfMemory(JSContext* cx);
namespace jit {
class JitCode;
class JitRealm {
friend class JitActivation;
// The JitRealm stores stubs to concatenate strings inline and perform RegExp
// calls inline. These bake in zone and realm specific pointers and can't be
// stored in JitRuntime. They also are dependent on the value of
// 'initialStringHeap' and must be flushed when its value changes.
//
// These are weak pointers, but they can by accessed during off-thread Ion
// compilation and therefore can't use the usual read barrier. Instead, we
// record which stubs have been read and perform the appropriate barriers in
// CodeGenerator::link().
enum StubIndex : uint32_t {
StringConcat = 0,
RegExpMatcher,
RegExpSearcher,
RegExpExecMatch,
RegExpExecTest,
Count
};
mozilla::EnumeratedArray<StubIndex, StubIndex::Count, WeakHeapPtr<JitCode*>>
stubs_;
gc::Heap initialStringHeap;
JitCode* generateStringConcatStub(JSContext* cx);
JitCode* generateRegExpMatcherStub(JSContext* cx);
JitCode* generateRegExpSearcherStub(JSContext* cx);
JitCode* generateRegExpExecMatchStub(JSContext* cx);
JitCode* generateRegExpExecTestStub(JSContext* cx);
JitCode* getStubNoBarrier(StubIndex stub,
uint32_t* requiredBarriersOut) const {
MOZ_ASSERT(CurrentThreadIsIonCompiling());
*requiredBarriersOut |= 1 << uint32_t(stub);
return stubs_[stub].unbarrieredGet();
}
public:
JitRealm();
void initialize(bool zoneHasNurseryStrings);
// Initialize code stubs only used by Ion, not Baseline.
[[nodiscard]] bool ensureIonStubsExist(JSContext* cx) {
if (stubs_[StringConcat]) {
return true;
}
stubs_[StringConcat] = generateStringConcatStub(cx);
return stubs_[StringConcat];
}
void traceWeak(JSTracer* trc, JS::Realm* realm);
void discardStubs() {
for (WeakHeapPtr<JitCode*>& stubRef : stubs_) {
stubRef = nullptr;
}
}
bool hasStubs() const {
for (const WeakHeapPtr<JitCode*>& stubRef : stubs_) {
if (stubRef) {
return true;
}
}
return false;
}
void setStringsCanBeInNursery(bool allow) {
MOZ_ASSERT(!hasStubs());
initialStringHeap = allow ? gc::Heap::Default : gc::Heap::Tenured;
}
gc::Heap getInitialStringHeap() const { return initialStringHeap; }
JitCode* stringConcatStubNoBarrier(uint32_t* requiredBarriersOut) const {
return getStubNoBarrier(StringConcat, requiredBarriersOut);
}
JitCode* regExpMatcherStubNoBarrier(uint32_t* requiredBarriersOut) const {
return getStubNoBarrier(RegExpMatcher, requiredBarriersOut);
}
[[nodiscard]] JitCode* ensureRegExpMatcherStubExists(JSContext* cx) {
if (JitCode* code = stubs_[RegExpMatcher]) {
return code;
}
stubs_[RegExpMatcher] = generateRegExpMatcherStub(cx);
return stubs_[RegExpMatcher];
}
JitCode* regExpSearcherStubNoBarrier(uint32_t* requiredBarriersOut) const {
return getStubNoBarrier(RegExpSearcher, requiredBarriersOut);
}
[[nodiscard]] JitCode* ensureRegExpSearcherStubExists(JSContext* cx) {
if (JitCode* code = stubs_[RegExpSearcher]) {
return code;
}
stubs_[RegExpSearcher] = generateRegExpSearcherStub(cx);
return stubs_[RegExpSearcher];
}
JitCode* regExpExecMatchStubNoBarrier(uint32_t* requiredBarriersOut) const {
return getStubNoBarrier(RegExpExecMatch, requiredBarriersOut);
}
[[nodiscard]] JitCode* ensureRegExpExecMatchStubExists(JSContext* cx) {
if (JitCode* code = stubs_[RegExpExecMatch]) {
return code;
}
stubs_[RegExpExecMatch] = generateRegExpExecMatchStub(cx);
return stubs_[RegExpExecMatch];
}
JitCode* regExpExecTestStubNoBarrier(uint32_t* requiredBarriersOut) const {
return getStubNoBarrier(RegExpExecTest, requiredBarriersOut);
}
[[nodiscard]] JitCode* ensureRegExpExecTestStubExists(JSContext* cx) {
if (JitCode* code = stubs_[RegExpExecTest]) {
return code;
}
stubs_[RegExpExecTest] = generateRegExpExecTestStub(cx);
return stubs_[RegExpExecTest];
}
// Perform the necessary read barriers on stubs described by the bitmasks
// passed in. This function can only be called from the main thread.
//
// The stub pointers must still be valid by the time these methods are
// called. This is arranged by cancelling off-thread Ion compilation at the
// start of GC and at the start of sweeping.
void performStubReadBarriers(uint32_t stubsToBarrier) const;
size_t sizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
static constexpr size_t offsetOfRegExpMatcherStub() {
return offsetof(JitRealm, stubs_) + RegExpMatcher * sizeof(uintptr_t);
}
static constexpr size_t offsetOfRegExpSearcherStub() {
return offsetof(JitRealm, stubs_) + RegExpSearcher * sizeof(uintptr_t);
}
static constexpr size_t offsetOfRegExpExecMatchStub() {
return offsetof(JitRealm, stubs_) + RegExpExecMatch * sizeof(uintptr_t);
}
static constexpr size_t offsetOfRegExpExecTestStub() {
return offsetof(JitRealm, stubs_) + RegExpExecTest * sizeof(uintptr_t);
}
};
} // namespace jit
} // namespace js
#endif /* jit_JitRealm_h */
|
