2 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
3 * vim: set ts=8 sts=2 et sw=2 tw=80:
4 * This Source Code Form is subject to the terms of the Mozilla Public
5 * License, v. 2.0. If a copy of the MPL was not distributed with this
6 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
9 * GC-internal definition of GC cell kinds.
12 #ifndef gc_AllocKind_h
13 #define gc_AllocKind_h
15 #include "mozilla/EnumeratedArray.h"
16 #include "mozilla/EnumeratedRange.h"
21 #include "js/TraceKind.h"
23 class JSDependentString
;
24 class JSExternalString
;
25 class JSFatInlineString
;
28 class JSThinInlineString
;
37 class DictionaryPropMap
;
38 class DictionaryShape
;
45 // The GC allocation kinds.
47 // These are defined by macros which enumerate the different allocation kinds
48 // and supply the following information:
50 // - the corresponding AllocKind
51 // - their JS::TraceKind
52 // - their C++ base type
53 // - a C++ type of the correct size
54 // - whether they can be finalized on the background thread
55 // - whether they can be allocated in the nursery (this is true for foreground
56 // finalized objects but these will can only actually be allocated in the
57 // nursery if JSCLASS_SKIP_NURSERY_FINALIZE is set)
58 // - whether they can be compacted
61 #define FOR_EACH_OBJECT_ALLOCKIND(D) \
62 /* AllocKind TraceKind TypeName SizedType BGFinal Nursery Compact */ \
63 D(FUNCTION, Object, JSObject, JSObject_Slots4, true, true, true) \
64 D(FUNCTION_EXTENDED, Object, JSObject, JSObject_Slots7, true, true, true) \
65 D(OBJECT0, Object, JSObject, JSObject_Slots0, false, true, true) \
66 D(OBJECT0_BACKGROUND, Object, JSObject, JSObject_Slots0, true, true, true) \
67 D(OBJECT2, Object, JSObject, JSObject_Slots2, false, true, true) \
68 D(OBJECT2_BACKGROUND, Object, JSObject, JSObject_Slots2, true, true, true) \
69 D(ARRAYBUFFER4, Object, JSObject, JSObject_Slots4, true, true, true) \
70 D(OBJECT4, Object, JSObject, JSObject_Slots4, false, true, true) \
71 D(OBJECT4_BACKGROUND, Object, JSObject, JSObject_Slots4, true, true, true) \
72 D(ARRAYBUFFER8, Object, JSObject, JSObject_Slots8, true, true, true) \
73 D(OBJECT8, Object, JSObject, JSObject_Slots8, false, true, true) \
74 D(OBJECT8_BACKGROUND, Object, JSObject, JSObject_Slots8, true, true, true) \
75 D(ARRAYBUFFER12, Object, JSObject, JSObject_Slots12, true, true, true) \
76 D(OBJECT12, Object, JSObject, JSObject_Slots12, false, true, true) \
77 D(OBJECT12_BACKGROUND, Object, JSObject, JSObject_Slots12, true, true, true) \
78 D(ARRAYBUFFER16, Object, JSObject, JSObject_Slots16, true, true, true) \
79 D(OBJECT16, Object, JSObject, JSObject_Slots16, false, true, true) \
80 D(OBJECT16_BACKGROUND, Object, JSObject, JSObject_Slots16, true, true, true)
82 #define FOR_EACH_NONOBJECT_NONNURSERY_ALLOCKIND(D) \
83 /* AllocKind TraceKind TypeName SizedType BGFinal Nursery Compact */ \
84 D(SCRIPT, Script, js::BaseScript, js::BaseScript, false, false, true) \
85 D(SHAPE, Shape, js::Shape, js::SizedShape, true, false, true) \
86 D(BASE_SHAPE, BaseShape, js::BaseShape, js::BaseShape, true, false, true) \
87 D(GETTER_SETTER, GetterSetter, js::GetterSetter, js::GetterSetter, true, false, true) \
88 D(COMPACT_PROP_MAP, PropMap, js::CompactPropMap, js::CompactPropMap, true, false, true) \
89 D(NORMAL_PROP_MAP, PropMap, js::NormalPropMap, js::NormalPropMap, true, false, true) \
90 D(DICT_PROP_MAP, PropMap, js::DictionaryPropMap, js::DictionaryPropMap, true, false, true) \
91 D(EXTERNAL_STRING, String, JSExternalString, JSExternalString, true, false, true) \
92 D(FAT_INLINE_ATOM, String, js::FatInlineAtom, js::FatInlineAtom, true, false, false) \
93 D(ATOM, String, js::NormalAtom, js::NormalAtom, true, false, false) \
94 D(SYMBOL, Symbol, JS::Symbol, JS::Symbol, true, false, false) \
95 D(JITCODE, JitCode, js::jit::JitCode, js::jit::JitCode, false, false, false) \
96 D(SCOPE, Scope, js::Scope, js::Scope, true, false, true) \
97 D(REGEXP_SHARED, RegExpShared, js::RegExpShared, js::RegExpShared, true, false, true)
99 #define FOR_EACH_NONOBJECT_NURSERY_ALLOCKIND(D) \
100 /* AllocKind TraceKind TypeName SizedType BGFinal Nursery Compact */ \
101 D(BIGINT, BigInt, JS::BigInt, JS::BigInt, true, true, true)
103 #define FOR_EACH_NURSERY_STRING_ALLOCKIND(D) \
104 D(FAT_INLINE_STRING, String, JSFatInlineString, JSFatInlineString, true, true, true) \
105 D(STRING, String, JSString, JSString, true, true, true)
108 #define FOR_EACH_NONOBJECT_ALLOCKIND(D) \
109 FOR_EACH_NONOBJECT_NONNURSERY_ALLOCKIND(D) \
110 FOR_EACH_NONOBJECT_NURSERY_ALLOCKIND(D) \
111 FOR_EACH_NURSERY_STRING_ALLOCKIND(D)
113 #define FOR_EACH_ALLOCKIND(D) \
114 FOR_EACH_OBJECT_ALLOCKIND(D) \
115 FOR_EACH_NONOBJECT_ALLOCKIND(D)
117 #define DEFINE_ALLOC_KIND(allocKind, _1, _2, _3, _4, _5, _6) allocKind,
118 enum class AllocKind
: uint8_t {
120 FOR_EACH_OBJECT_ALLOCKIND(DEFINE_ALLOC_KIND
)
123 OBJECT_LAST
= OBJECT_LIMIT
- 1,
125 FOR_EACH_NONOBJECT_ALLOCKIND(DEFINE_ALLOC_KIND
)
133 OBJECT_FIRST
= FUNCTION
// Hardcoded to first object kind.
136 #undef DEFINE_ALLOC_KIND
138 static_assert(int(AllocKind::FIRST
) == 0,
139 "Various places depend on AllocKind starting at 0");
140 static_assert(int(AllocKind::OBJECT_FIRST
) == 0,
141 "OBJECT_FIRST must be defined as the first object kind");
143 constexpr size_t AllocKindCount
= size_t(AllocKind::LIMIT
);
146 * A flag specifying either the tenured heap or a default heap (which may be
147 * either the nursery or the tenured heap).
149 * This allows an allocation site to request a heap based upon the estimated
150 * lifetime or lifetime requirements of objects allocated from that site.
152 * Order is important as these are numerically compared.
154 enum class Heap
: uint8_t { Default
= 0, Tenured
= 1 };
156 constexpr bool IsAllocKind(AllocKind kind
) {
157 return kind
>= AllocKind::FIRST
&& kind
<= AllocKind::LIMIT
;
160 constexpr bool IsValidAllocKind(AllocKind kind
) {
161 return kind
>= AllocKind::FIRST
&& kind
<= AllocKind::LAST
;
164 const char* AllocKindName(AllocKind kind
);
166 constexpr bool IsObjectAllocKind(AllocKind kind
) {
167 return kind
>= AllocKind::OBJECT_FIRST
&& kind
<= AllocKind::OBJECT_LAST
;
170 constexpr bool IsShapeAllocKind(AllocKind kind
) {
171 return kind
== AllocKind::SHAPE
;
174 // Returns a sequence for use in a range-based for loop,
175 // to iterate over all alloc kinds.
176 constexpr auto AllAllocKinds() {
177 return mozilla::MakeEnumeratedRange(AllocKind::FIRST
, AllocKind::LIMIT
);
180 // Returns a sequence for use in a range-based for loop,
181 // to iterate over all object alloc kinds.
182 constexpr auto ObjectAllocKinds() {
183 return mozilla::MakeEnumeratedRange(AllocKind::OBJECT_FIRST
,
184 AllocKind::OBJECT_LIMIT
);
187 // Returns a sequence for use in a range-based for loop,
188 // to iterate over alloc kinds from |first| to |limit|, exclusive.
189 constexpr auto SomeAllocKinds(AllocKind first
= AllocKind::FIRST
,
190 AllocKind limit
= AllocKind::LIMIT
) {
191 MOZ_ASSERT(IsAllocKind(first
), "|first| is not a valid AllocKind!");
192 MOZ_ASSERT(IsAllocKind(limit
), "|limit| is not a valid AllocKind!");
193 return mozilla::MakeEnumeratedRange(first
, limit
);
196 // AllAllocKindArray<ValueType> gives an enumerated array of ValueTypes,
197 // with each index corresponding to a particular alloc kind.
198 template <typename ValueType
>
199 using AllAllocKindArray
=
200 mozilla::EnumeratedArray
<AllocKind
, AllocKind::LIMIT
, ValueType
>;
202 // ObjectAllocKindArray<ValueType> gives an enumerated array of ValueTypes,
203 // with each index corresponding to a particular object alloc kind.
204 template <typename ValueType
>
205 using ObjectAllocKindArray
=
206 mozilla::EnumeratedArray
<AllocKind
, AllocKind::OBJECT_LIMIT
, ValueType
>;
209 * Map from C++ type to alloc kind for non-object types. JSObject does not have
210 * a 1:1 mapping, so must use Arena::thingSize.
212 * The AllocKind is available as MapTypeToAllocKind<SomeType>::kind.
214 * There are specializations for strings and shapes since more than one derived
215 * type shares the same alloc kind.
217 template <typename T
>
218 struct MapTypeToAllocKind
{};
219 #define EXPAND_MAPTYPETOALLOCKIND(allocKind, traceKind, type, sizedType, \
220 bgFinal, nursery, compact) \
222 struct MapTypeToAllocKind<type> { \
223 static const AllocKind kind = AllocKind::allocKind; \
225 FOR_EACH_NONOBJECT_ALLOCKIND(EXPAND_MAPTYPETOALLOCKIND
)
226 #undef EXPAND_MAPTYPETOALLOCKIND
229 struct MapTypeToAllocKind
<JSDependentString
> {
230 static const AllocKind kind
= AllocKind::STRING
;
233 struct MapTypeToAllocKind
<JSRope
> {
234 static const AllocKind kind
= AllocKind::STRING
;
237 struct MapTypeToAllocKind
<JSLinearString
> {
238 static const AllocKind kind
= AllocKind::STRING
;
241 struct MapTypeToAllocKind
<JSThinInlineString
> {
242 static const AllocKind kind
= AllocKind::STRING
;
245 struct MapTypeToAllocKind
<js::ThinInlineAtom
> {
246 static const AllocKind kind
= AllocKind::ATOM
;
250 struct MapTypeToAllocKind
<js::SharedShape
> {
251 static const AllocKind kind
= AllocKind::SHAPE
;
254 struct MapTypeToAllocKind
<js::DictionaryShape
> {
255 static const AllocKind kind
= AllocKind::SHAPE
;
258 struct MapTypeToAllocKind
<js::ProxyShape
> {
259 static const AllocKind kind
= AllocKind::SHAPE
;
262 struct MapTypeToAllocKind
<js::WasmGCShape
> {
263 static const AllocKind kind
= AllocKind::SHAPE
;
266 constexpr JS::TraceKind
MapAllocToTraceKind(AllocKind kind
) {
267 constexpr JS::TraceKind map
[] = {
268 #define EXPAND_ELEMENT(allocKind, traceKind, type, sizedType, bgFinal, \
270 JS::TraceKind::traceKind,
271 FOR_EACH_ALLOCKIND(EXPAND_ELEMENT
)
272 #undef EXPAND_ELEMENT
275 static_assert(std::size(map
) == AllocKindCount
,
276 "AllocKind-to-TraceKind mapping must be in sync");
277 return map
[size_t(kind
)];
280 constexpr bool IsNurseryAllocable(AllocKind kind
) {
281 MOZ_ASSERT(IsValidAllocKind(kind
));
283 constexpr bool map
[] = {
284 #define DEFINE_NURSERY_ALLOCABLE(_1, _2, _3, _4, _5, nursery, _6) nursery,
285 FOR_EACH_ALLOCKIND(DEFINE_NURSERY_ALLOCABLE
)
286 #undef DEFINE_NURSERY_ALLOCABLE
289 static_assert(std::size(map
) == AllocKindCount
,
290 "IsNurseryAllocable sanity check");
291 return map
[size_t(kind
)];
294 constexpr bool IsBackgroundFinalized(AllocKind kind
) {
295 MOZ_ASSERT(IsValidAllocKind(kind
));
297 constexpr bool map
[] = {
298 #define DEFINE_BACKGROUND_FINALIZED(_1, _2, _3, _4, bgFinal, _5, _6) bgFinal,
299 FOR_EACH_ALLOCKIND(DEFINE_BACKGROUND_FINALIZED
)
300 #undef DEFINE_BACKGROUND_FINALIZED
303 static_assert(std::size(map
) == AllocKindCount
,
304 "IsBackgroundFinalized sanity check");
305 return map
[size_t(kind
)];
308 constexpr bool IsForegroundFinalized(AllocKind kind
) {
309 return !IsBackgroundFinalized(kind
);
312 constexpr bool IsCompactingKind(AllocKind kind
) {
313 MOZ_ASSERT(IsValidAllocKind(kind
));
315 constexpr bool map
[] = {
316 #define DEFINE_COMPACTING_KIND(_1, _2, _3, _4, _5, _6, compact) compact,
317 FOR_EACH_ALLOCKIND(DEFINE_COMPACTING_KIND
)
318 #undef DEFINE_COMPACTING_KIND
321 static_assert(std::size(map
) == AllocKindCount
,
322 "IsCompactingKind sanity check");
323 return map
[size_t(kind
)];
326 constexpr bool IsMovableKind(AllocKind kind
) {
327 return IsNurseryAllocable(kind
) || IsCompactingKind(kind
);
333 #endif /* gc_AllocKind_h */