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/* -*- 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 */
#ifndef gc_Allocator_h
#define gc_Allocator_h
#include <stdint.h>
#include "gc/AllocKind.h"
#include "js/RootingAPI.h"
class JSFatInlineString;
namespace js {
enum AllowGC { NoGC = 0, CanGC = 1 };
namespace gc {
* This flag allows an allocation site to request a specific heap based upon the
* estimated lifetime or lifetime requirements of objects allocated from that
* site.
enum InitialHeap : uint8_t { DefaultHeap, TenuredHeap };
} // namespace gc
// Allocate a new GC thing that's not a JSObject or a string.
// After a successful allocation the caller must fully initialize the thing
// before calling any function that can potentially trigger GC. This will ensure
// that GC tracing never sees junk values stored in the partially initialized
// thing.
template <typename T, AllowGC allowGC = CanGC>
T* Allocate(JSContext* cx);
// Allocate a JSObject.
// A longer signature that includes additional information in support of various
// optimizations. If dynamic slots are requested they will be allocated and the
// pointer stored directly in |NativeObject::slots_|.
template <AllowGC allowGC = CanGC>
JSObject* AllocateObject(JSContext* cx, gc::AllocKind kind,
size_t nDynamicSlots, gc::InitialHeap heap,
const JSClass* clasp);
// Internal function used for nursery-allocatable strings.
template <typename StringAllocT, AllowGC allowGC = CanGC>
StringAllocT* AllocateStringImpl(JSContext* cx, gc::InitialHeap heap);
// Allocate a string.
// Use for nursery-allocatable strings. Returns a value cast to the correct
// type.
template <typename StringT, AllowGC allowGC = CanGC>
StringT* AllocateString(JSContext* cx, gc::InitialHeap heap) {
return static_cast<StringT*>(AllocateStringImpl<JSString, allowGC>(cx, heap));
// Specialization for JSFatInlineString that must use a different allocation
// type. Note that we have to explicitly specialize for both values of AllowGC
// because partial function specialization is not allowed.
template <>
inline JSFatInlineString* AllocateString<JSFatInlineString, CanGC>(
JSContext* cx, gc::InitialHeap heap) {
return static_cast<JSFatInlineString*>(
js::AllocateStringImpl<JSFatInlineString, CanGC>(cx, heap));
template <>
inline JSFatInlineString* AllocateString<JSFatInlineString, NoGC>(
JSContext* cx, gc::InitialHeap heap) {
return static_cast<JSFatInlineString*>(
js::AllocateStringImpl<JSFatInlineString, NoGC>(cx, heap));
// Allocate a BigInt.
// Use for nursery-allocatable BigInt.
template <AllowGC allowGC = CanGC>
JS::BigInt* AllocateBigInt(JSContext* cx, gc::InitialHeap heap);
} // namespace js
#endif // gc_Allocator_h