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
|
/* -*- 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/. */
/*
* Inline definitions of the CellAllocator methods.
*
* This is included from JSContext-inl.h for the definiton of JSContext::newCell
* and shouldn't need to be included elsewhere.
*/
#ifndef gc_Allocator_inl_h
#define gc_Allocator_inl_h
#include "gc/Allocator.h"
#include "gc/Cell.h"
#include "gc/Zone.h"
#include "js/Class.h"
#include "js/RootingAPI.h"
#include "gc/Nursery-inl.h"
namespace js {
namespace gc {
template <typename T, AllowGC allowGC, typename... Args>
T* CellAllocator::NewCell(JSContext* cx, Args&&... args) {
static_assert(std::is_base_of_v<gc::Cell, T>);
// Objects. See the valid parameter list in NewObject, above.
if constexpr (std::is_base_of_v<JSObject, T>) {
return NewObject<T, allowGC>(cx, std::forward<Args>(args)...);
}
// BigInt
else if constexpr (std::is_base_of_v<JS::BigInt, T>) {
return NewBigInt<T, allowGC>(cx, std::forward<Args>(args)...);
}
// "Normal" strings (all of which can be nursery allocated). Atoms and
// external strings will fall through to the generic code below. All other
// strings go through NewString, which will forward the arguments to the
// appropriate string class's constructor.
else if constexpr (std::is_base_of_v<JSString, T> &&
!std::is_base_of_v<JSAtom, T> &&
!std::is_base_of_v<JSExternalString, T>) {
return NewString<T, allowGC>(cx, std::forward<Args>(args)...);
}
else {
// Allocate a new tenured GC thing that's not nursery-allocatable. Use
// cx->newCell<T>(...), where the parameters are forwarded to the type's
// constructor.
return NewTenuredCell<T, allowGC>(cx, std::forward<Args>(args)...);
}
}
template <typename T, AllowGC allowGC, typename... Args>
/* static */
T* CellAllocator::NewString(JSContext* cx, gc::Heap heap, Args&&... args) {
static_assert(std::is_base_of_v<JSString, T>);
gc::AllocKind kind = gc::MapTypeToAllocKind<T>::kind;
void* ptr = AllocNurseryOrTenuredCell<JS::TraceKind::String, allowGC>(
cx, kind, sizeof(T), heap, nullptr);
if (MOZ_UNLIKELY(!ptr)) {
return nullptr;
}
return new (mozilla::KnownNotNull, ptr) T(std::forward<Args>(args)...);
}
template <typename T, AllowGC allowGC>
/* static */
T* CellAllocator::NewBigInt(JSContext* cx, Heap heap) {
void* ptr = AllocNurseryOrTenuredCell<JS::TraceKind::BigInt, allowGC>(
cx, gc::AllocKind::BIGINT, sizeof(T), heap, nullptr);
if (MOZ_UNLIKELY(!ptr)) {
return nullptr;
}
return new (mozilla::KnownNotNull, ptr) T();
}
template <typename T, AllowGC allowGC>
/* static */
T* CellAllocator::NewObject(JSContext* cx, gc::AllocKind kind, gc::Heap heap,
const JSClass* clasp, gc::AllocSite* site) {
MOZ_ASSERT(IsObjectAllocKind(kind));
MOZ_ASSERT_IF(heap != gc::Heap::Tenured && clasp->hasFinalize() &&
!clasp->isProxyObject(),
CanNurseryAllocateFinalizedClass(clasp));
size_t thingSize = JSObject::thingSize(kind);
void* cell = AllocNurseryOrTenuredCell<JS::TraceKind::Object, allowGC>(
cx, kind, thingSize, heap, site);
if (MOZ_UNLIKELY(!cell)) {
return nullptr;
}
return new (mozilla::KnownNotNull, cell) T();
}
template <JS::TraceKind traceKind, AllowGC allowGC>
/* static */
void* CellAllocator::AllocNurseryOrTenuredCell(JSContext* cx,
gc::AllocKind allocKind,
size_t thingSize, gc::Heap heap,
AllocSite* site) {
MOZ_ASSERT(IsNurseryAllocable(allocKind));
MOZ_ASSERT(MapAllocToTraceKind(allocKind) == traceKind);
MOZ_ASSERT(thingSize == Arena::thingSize(allocKind));
MOZ_ASSERT_IF(site && site->initialHeap() == Heap::Tenured,
heap == Heap::Tenured);
if (!PreAllocChecks<allowGC>(cx, allocKind)) {
return nullptr;
}
JS::Zone* zone = cx->zone();
gc::Heap minHeapToTenure = CheckedHeap(zone->minHeapToTenure(traceKind));
if (CheckedHeap(heap) < minHeapToTenure) {
if (!site) {
site = zone->unknownAllocSite(traceKind);
}
void* ptr = cx->nursery().tryAllocateCell(site, thingSize, traceKind);
if (MOZ_LIKELY(ptr)) {
return ptr;
}
return RetryNurseryAlloc<allowGC>(cx, traceKind, allocKind, thingSize,
site);
}
return TryNewTenuredCell<allowGC>(cx, allocKind, thingSize);
}
/* static */
MOZ_ALWAYS_INLINE gc::Heap CellAllocator::CheckedHeap(gc::Heap heap) {
if (heap > Heap::Tenured) {
// This helps the compiler to see that nursery allocation is never
// possible if Heap::Tenured is specified.
MOZ_MAKE_COMPILER_ASSUME_IS_UNREACHABLE("Bad gc::Heap value");
}
return heap;
}
template <typename T, AllowGC allowGC, typename... Args>
/* static */
T* CellAllocator::NewTenuredCell(JSContext* cx, Args&&... args) {
gc::AllocKind kind = gc::MapTypeToAllocKind<T>::kind;
void* cell = AllocTenuredCell<allowGC>(cx, kind, sizeof(T));
if (MOZ_UNLIKELY(!cell)) {
return nullptr;
}
return new (mozilla::KnownNotNull, cell) T(std::forward<Args>(args)...);
}
} // namespace gc
} // namespace js
#endif // gc_Allocator_inl_h
|
