1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
2 * vim: set ts=8 sts=2 et sw=2 tw=80:
3 * This Source Code Form is subject to the terms of the Mozilla Public
4 * License, v. 2.0. If a copy of the MPL was not distributed with this
5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
7 #ifndef gc_FinalizationObservers_h
8 #define gc_FinalizationObservers_h
10 #include "gc/Barrier.h"
11 #include "gc/WeakMap.h"
12 #include "gc/ZoneAllocator.h"
13 #include "js/GCHashTable.h"
14 #include "js/GCVector.h"
18 class FinalizationRegistryObject
;
19 class FinalizationRecordObject
;
24 // Per-zone data structures to support FinalizationRegistry and WeakRef.
25 class FinalizationObservers
{
28 // The set of all finalization registries in the associated zone. These are
29 // direct pointers and are not wrapped.
31 GCHashSet
<HeapPtr
<JSObject
*>, StableCellHasher
<HeapPtr
<JSObject
*>>,
33 RegistrySet registries
;
35 // A vector of FinalizationRecord objects, or CCWs to them.
36 using RecordVector
= GCVector
<HeapPtr
<JSObject
*>, 1, ZoneAllocPolicy
>;
38 // A map from finalization registry targets to a vector of finalization
39 // records representing registries that the target is registered with and
40 // their associated held values. The records may be in other zones and are
41 // wrapped appropriately.
43 GCHashMap
<HeapPtr
<JSObject
*>, RecordVector
,
44 StableCellHasher
<HeapPtr
<JSObject
*>>, ZoneAllocPolicy
>;
47 // A weak map used as a set of cross-zone wrappers. This is used for both
48 // finalization registries and weak refs. For the former it has wrappers to
49 // finalization record objects and for the latter wrappers to weak refs.
51 // The weak map marking rules keep the wrappers alive while their targets are
52 // alive and ensure that they are both swept in the same sweep group.
53 using WrapperWeakSet
= ObjectValueWeakMap
;
54 WrapperWeakSet crossZoneRecords
;
56 // A map of weak ref targets to a vector of weak refs that are observing the
57 // target. The weak refs may be in other zones and are wrapped appropriately.
58 using WeakRefHeapPtrVector
=
59 GCVector
<js::HeapPtr
<JSObject
*>, 1, js::ZoneAllocPolicy
>;
61 GCHashMap
<HeapPtr
<JSObject
*>, WeakRefHeapPtrVector
,
62 StableCellHasher
<HeapPtr
<JSObject
*>>, ZoneAllocPolicy
>;
63 WeakRefMap weakRefMap
;
65 // A weak map used as a set of cross-zone weak refs wrappers.
66 WrapperWeakSet crossZoneWeakRefs
;
69 explicit FinalizationObservers(Zone
* zone
);
70 ~FinalizationObservers();
72 // FinalizationRegistry support:
73 bool addRegistry(Handle
<FinalizationRegistryObject
*> registry
);
74 bool addRecord(HandleObject target
, HandleObject record
);
77 void updateForRemovedRecord(JSObject
* wrapper
,
78 FinalizationRecordObject
* record
);
81 bool addWeakRefTarget(Handle
<JSObject
*> target
, Handle
<JSObject
*> weakRef
);
82 void removeWeakRefTarget(Handle
<JSObject
*> target
,
83 Handle
<WeakRefObject
*> weakRef
);
85 void unregisterWeakRefWrapper(JSObject
* wrapper
, WeakRefObject
* weakRef
);
87 void traceRoots(JSTracer
* trc
);
88 void traceWeakEdges(JSTracer
* trc
);
91 void checkTables() const;
95 bool addCrossZoneWrapper(WrapperWeakSet
& weakSet
, JSObject
* wrapper
);
96 void removeCrossZoneWrapper(WrapperWeakSet
& weakSet
, JSObject
* wrapper
);
98 void updateForRemovedWeakRef(JSObject
* wrapper
, WeakRefObject
* weakRef
);
100 void traceWeakFinalizationRegistryEdges(JSTracer
* trc
);
101 void traceWeakWeakRefEdges(JSTracer
* trc
);
102 void traceWeakWeakRefVector(JSTracer
* trc
, WeakRefHeapPtrVector
& weakRefs
,
105 static bool shouldRemoveRecord(FinalizationRecordObject
* record
);
108 // Per-global data structures to support FinalizationRegistry.
109 class FinalizationRegistryGlobalData
{
110 // Set of finalization records for finalization registries in this
111 // realm. These are traced as part of the realm's global.
113 GCHashSet
<HeapPtr
<JSObject
*>, StableCellHasher
<HeapPtr
<JSObject
*>>,
118 explicit FinalizationRegistryGlobalData(Zone
* zone
);
120 bool addRecord(FinalizationRecordObject
* record
);
121 void removeRecord(FinalizationRecordObject
* record
);
123 void trace(JSTracer
* trc
);
129 #endif // gc_FinalizationObservers_h