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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
/*
* GC-internal definition of GC cell kinds.
*/
#ifndef gc_AllocKind_h
#define gc_AllocKind_h
#include "mozilla/EnumeratedArray.h"
#include "mozilla/EnumeratedRange.h"
#include <iterator>
#include <stdint.h>
#include "js/TraceKind.h"
class JSDependentString;
class JSExternalString;
class JSFatInlineString;
class JSLinearString;
class JSRope;
class JSThinInlineString;
namespace js {
class CompactPropMap;
class FatInlineAtom;
class ThinInlineAtom;
class NormalAtom;
class NormalPropMap;
class DictionaryPropMap;
class DictionaryShape;
class SharedShape;
class ProxyShape;
class WasmGCShape;
namespace gc {
// The GC allocation kinds.
//
// These are defined by macros which enumerate the different allocation kinds
// and supply the following information:
//
// - the corresponding AllocKind
// - their JS::TraceKind
// - their C++ base type
// - a C++ type of the correct size
// - whether they can be finalized on the background thread
// - whether they can be allocated in the nursery (this is true for foreground
// finalized objects but these will can only actually be allocated in the
// nursery if JSCLASS_SKIP_NURSERY_FINALIZE is set)
// - whether they can be compacted
// clang-format off
#define FOR_EACH_OBJECT_ALLOCKIND(D) \
/* AllocKind TraceKind TypeName SizedType BGFinal Nursery Compact */ \
D(FUNCTION, Object, JSObject, JSObject_Slots4, true, true, true) \
D(FUNCTION_EXTENDED, Object, JSObject, JSObject_Slots7, true, true, true) \
D(OBJECT0, Object, JSObject, JSObject_Slots0, false, true, true) \
D(OBJECT0_BACKGROUND, Object, JSObject, JSObject_Slots0, true, true, true) \
D(OBJECT2, Object, JSObject, JSObject_Slots2, false, true, true) \
D(OBJECT2_BACKGROUND, Object, JSObject, JSObject_Slots2, true, true, true) \
D(ARRAYBUFFER4, Object, JSObject, JSObject_Slots4, true, true, true) \
D(OBJECT4, Object, JSObject, JSObject_Slots4, false, true, true) \
D(OBJECT4_BACKGROUND, Object, JSObject, JSObject_Slots4, true, true, true) \
D(ARRAYBUFFER8, Object, JSObject, JSObject_Slots8, true, true, true) \
D(OBJECT8, Object, JSObject, JSObject_Slots8, false, true, true) \
D(OBJECT8_BACKGROUND, Object, JSObject, JSObject_Slots8, true, true, true) \
D(ARRAYBUFFER12, Object, JSObject, JSObject_Slots12, true, true, true) \
D(OBJECT12, Object, JSObject, JSObject_Slots12, false, true, true) \
D(OBJECT12_BACKGROUND, Object, JSObject, JSObject_Slots12, true, true, true) \
D(ARRAYBUFFER16, Object, JSObject, JSObject_Slots16, true, true, true) \
D(OBJECT16, Object, JSObject, JSObject_Slots16, false, true, true) \
D(OBJECT16_BACKGROUND, Object, JSObject, JSObject_Slots16, true, true, true)
#define FOR_EACH_NONOBJECT_NONNURSERY_ALLOCKIND(D) \
/* AllocKind TraceKind TypeName SizedType BGFinal Nursery Compact */ \
D(SCRIPT, Script, js::BaseScript, js::BaseScript, false, false, true) \
D(SHAPE, Shape, js::Shape, js::SizedShape, true, false, true) \
D(BASE_SHAPE, BaseShape, js::BaseShape, js::BaseShape, true, false, true) \
D(GETTER_SETTER, GetterSetter, js::GetterSetter, js::GetterSetter, true, false, true) \
D(COMPACT_PROP_MAP, PropMap, js::CompactPropMap, js::CompactPropMap, true, false, true) \
D(NORMAL_PROP_MAP, PropMap, js::NormalPropMap, js::NormalPropMap, true, false, true) \
D(DICT_PROP_MAP, PropMap, js::DictionaryPropMap, js::DictionaryPropMap, true, false, true) \
D(EXTERNAL_STRING, String, JSExternalString, JSExternalString, true, false, true) \
D(FAT_INLINE_ATOM, String, js::FatInlineAtom, js::FatInlineAtom, true, false, false) \
D(ATOM, String, js::NormalAtom, js::NormalAtom, true, false, false) \
D(SYMBOL, Symbol, JS::Symbol, JS::Symbol, true, false, false) \
D(JITCODE, JitCode, js::jit::JitCode, js::jit::JitCode, false, false, false) \
D(SCOPE, Scope, js::Scope, js::Scope, true, false, true) \
D(REGEXP_SHARED, RegExpShared, js::RegExpShared, js::RegExpShared, true, false, true)
#define FOR_EACH_NONOBJECT_NURSERY_ALLOCKIND(D) \
/* AllocKind TraceKind TypeName SizedType BGFinal Nursery Compact */ \
D(BIGINT, BigInt, JS::BigInt, JS::BigInt, true, true, true)
#define FOR_EACH_NURSERY_STRING_ALLOCKIND(D) \
D(FAT_INLINE_STRING, String, JSFatInlineString, JSFatInlineString, true, true, true) \
D(STRING, String, JSString, JSString, true, true, true)
// clang-format on
#define FOR_EACH_NONOBJECT_ALLOCKIND(D) \
FOR_EACH_NONOBJECT_NONNURSERY_ALLOCKIND(D) \
FOR_EACH_NONOBJECT_NURSERY_ALLOCKIND(D) \
FOR_EACH_NURSERY_STRING_ALLOCKIND(D)
#define FOR_EACH_ALLOCKIND(D) \
FOR_EACH_OBJECT_ALLOCKIND(D) \
FOR_EACH_NONOBJECT_ALLOCKIND(D)
#define DEFINE_ALLOC_KIND(allocKind, _1, _2, _3, _4, _5, _6) allocKind,
enum class AllocKind : uint8_t {
// clang-format off
FOR_EACH_OBJECT_ALLOCKIND(DEFINE_ALLOC_KIND)
OBJECT_LIMIT,
OBJECT_LAST = OBJECT_LIMIT - 1,
FOR_EACH_NONOBJECT_ALLOCKIND(DEFINE_ALLOC_KIND)
LIMIT,
LAST = LIMIT - 1,
INVALID = LIMIT,
FIRST = 0,
OBJECT_FIRST = FUNCTION // Hardcoded to first object kind.
// clang-format on
};
#undef DEFINE_ALLOC_KIND
static_assert(int(AllocKind::FIRST) == 0,
"Various places depend on AllocKind starting at 0");
static_assert(int(AllocKind::OBJECT_FIRST) == 0,
"OBJECT_FIRST must be defined as the first object kind");
constexpr size_t AllocKindCount = size_t(AllocKind::LIMIT);
/*
* A flag specifying either the tenured heap or a default heap (which may be
* either the nursery or the tenured heap).
*
* This allows an allocation site to request a heap based upon the estimated
* lifetime or lifetime requirements of objects allocated from that site.
*
* Order is important as these are numerically compared.
*/
enum class Heap : uint8_t { Default = 0, Tenured = 1 };
constexpr bool IsAllocKind(AllocKind kind) {
return kind >= AllocKind::FIRST && kind <= AllocKind::LIMIT;
}
constexpr bool IsValidAllocKind(AllocKind kind) {
return kind >= AllocKind::FIRST && kind <= AllocKind::LAST;
}
const char* AllocKindName(AllocKind kind);
constexpr bool IsObjectAllocKind(AllocKind kind) {
return kind >= AllocKind::OBJECT_FIRST && kind <= AllocKind::OBJECT_LAST;
}
constexpr bool IsShapeAllocKind(AllocKind kind) {
return kind == AllocKind::SHAPE;
}
// Returns a sequence for use in a range-based for loop,
// to iterate over all alloc kinds.
constexpr auto AllAllocKinds() {
return mozilla::MakeEnumeratedRange(AllocKind::FIRST, AllocKind::LIMIT);
}
// Returns a sequence for use in a range-based for loop,
// to iterate over all object alloc kinds.
constexpr auto ObjectAllocKinds() {
return mozilla::MakeEnumeratedRange(AllocKind::OBJECT_FIRST,
AllocKind::OBJECT_LIMIT);
}
// Returns a sequence for use in a range-based for loop,
// to iterate over alloc kinds from |first| to |limit|, exclusive.
constexpr auto SomeAllocKinds(AllocKind first = AllocKind::FIRST,
AllocKind limit = AllocKind::LIMIT) {
MOZ_ASSERT(IsAllocKind(first), "|first| is not a valid AllocKind!");
MOZ_ASSERT(IsAllocKind(limit), "|limit| is not a valid AllocKind!");
return mozilla::MakeEnumeratedRange(first, limit);
}
// AllAllocKindArray<ValueType> gives an enumerated array of ValueTypes,
// with each index corresponding to a particular alloc kind.
template <typename ValueType>
using AllAllocKindArray =
mozilla::EnumeratedArray<AllocKind, ValueType, size_t(AllocKind::LIMIT)>;
// ObjectAllocKindArray<ValueType> gives an enumerated array of ValueTypes,
// with each index corresponding to a particular object alloc kind.
template <typename ValueType>
using ObjectAllocKindArray =
mozilla::EnumeratedArray<AllocKind, ValueType,
size_t(AllocKind::OBJECT_LIMIT)>;
/*
* Map from C++ type to alloc kind for non-object types. JSObject does not have
* a 1:1 mapping, so must use Arena::thingSize.
*
* The AllocKind is available as MapTypeToAllocKind<SomeType>::kind.
*
* There are specializations for strings and shapes since more than one derived
* type shares the same alloc kind.
*/
template <typename T>
struct MapTypeToAllocKind {};
#define EXPAND_MAPTYPETOALLOCKIND(allocKind, traceKind, type, sizedType, \
bgFinal, nursery, compact) \
template <> \
struct MapTypeToAllocKind<type> { \
static const AllocKind kind = AllocKind::allocKind; \
};
FOR_EACH_NONOBJECT_ALLOCKIND(EXPAND_MAPTYPETOALLOCKIND)
#undef EXPAND_MAPTYPETOALLOCKIND
template <>
struct MapTypeToAllocKind<JSDependentString> {
static const AllocKind kind = AllocKind::STRING;
};
template <>
struct MapTypeToAllocKind<JSRope> {
static const AllocKind kind = AllocKind::STRING;
};
template <>
struct MapTypeToAllocKind<JSLinearString> {
static const AllocKind kind = AllocKind::STRING;
};
template <>
struct MapTypeToAllocKind<JSThinInlineString> {
static const AllocKind kind = AllocKind::STRING;
};
template <>
struct MapTypeToAllocKind<js::ThinInlineAtom> {
static const AllocKind kind = AllocKind::ATOM;
};
template <>
struct MapTypeToAllocKind<js::SharedShape> {
static const AllocKind kind = AllocKind::SHAPE;
};
template <>
struct MapTypeToAllocKind<js::DictionaryShape> {
static const AllocKind kind = AllocKind::SHAPE;
};
template <>
struct MapTypeToAllocKind<js::ProxyShape> {
static const AllocKind kind = AllocKind::SHAPE;
};
template <>
struct MapTypeToAllocKind<js::WasmGCShape> {
static const AllocKind kind = AllocKind::SHAPE;
};
constexpr JS::TraceKind MapAllocToTraceKind(AllocKind kind) {
constexpr JS::TraceKind map[] = {
#define EXPAND_ELEMENT(allocKind, traceKind, type, sizedType, bgFinal, \
nursery, compact) \
JS::TraceKind::traceKind,
FOR_EACH_ALLOCKIND(EXPAND_ELEMENT)
#undef EXPAND_ELEMENT
};
static_assert(std::size(map) == AllocKindCount,
"AllocKind-to-TraceKind mapping must be in sync");
return map[size_t(kind)];
}
constexpr bool IsNurseryAllocable(AllocKind kind) {
MOZ_ASSERT(IsValidAllocKind(kind));
constexpr bool map[] = {
#define DEFINE_NURSERY_ALLOCABLE(_1, _2, _3, _4, _5, nursery, _6) nursery,
FOR_EACH_ALLOCKIND(DEFINE_NURSERY_ALLOCABLE)
#undef DEFINE_NURSERY_ALLOCABLE
};
static_assert(std::size(map) == AllocKindCount,
"IsNurseryAllocable sanity check");
return map[size_t(kind)];
}
constexpr bool IsBackgroundFinalized(AllocKind kind) {
MOZ_ASSERT(IsValidAllocKind(kind));
constexpr bool map[] = {
#define DEFINE_BACKGROUND_FINALIZED(_1, _2, _3, _4, bgFinal, _5, _6) bgFinal,
FOR_EACH_ALLOCKIND(DEFINE_BACKGROUND_FINALIZED)
#undef DEFINE_BACKGROUND_FINALIZED
};
static_assert(std::size(map) == AllocKindCount,
"IsBackgroundFinalized sanity check");
return map[size_t(kind)];
}
constexpr bool IsForegroundFinalized(AllocKind kind) {
return !IsBackgroundFinalized(kind);
}
constexpr bool IsCompactingKind(AllocKind kind) {
MOZ_ASSERT(IsValidAllocKind(kind));
constexpr bool map[] = {
#define DEFINE_COMPACTING_KIND(_1, _2, _3, _4, _5, _6, compact) compact,
FOR_EACH_ALLOCKIND(DEFINE_COMPACTING_KIND)
#undef DEFINE_COMPACTING_KIND
};
static_assert(std::size(map) == AllocKindCount,
"IsCompactingKind sanity check");
return map[size_t(kind)];
}
constexpr bool IsMovableKind(AllocKind kind) {
return IsNurseryAllocable(kind) || IsCompactingKind(kind);
}
} /* namespace gc */
} /* namespace js */
#endif /* gc_AllocKind_h */