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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 http://mozilla.org/MPL/2.0/. */
#ifndef gc_FinalizationObservers_h
#define gc_FinalizationObservers_h
#include "gc/Barrier.h"
#include "gc/WeakMap.h"
#include "gc/ZoneAllocator.h"
#include "js/GCHashTable.h"
#include "js/GCVector.h"
namespace js {
class FinalizationRegistryObject;
class FinalizationRecordObject;
class WeakRefObject;
namespace gc {
// Per-zone data structures to support FinalizationRegistry and WeakRef.
class FinalizationObservers {
Zone* const zone;
// The set of all finalization registries in the associated zone. These are
// direct pointers and are not wrapped.
using RegistrySet =
GCHashSet<HeapPtr<JSObject*>, StableCellHasher<HeapPtr<JSObject*>>,
ZoneAllocPolicy>;
RegistrySet registries;
// A vector of FinalizationRecord objects, or CCWs to them.
using RecordVector = GCVector<HeapPtr<JSObject*>, 1, ZoneAllocPolicy>;
// A map from finalization registry targets to a vector of finalization
// records representing registries that the target is registered with and
// their associated held values. The records may be in other zones and are
// wrapped appropriately.
using RecordMap =
GCHashMap<HeapPtr<JSObject*>, RecordVector,
StableCellHasher<HeapPtr<JSObject*>>, ZoneAllocPolicy>;
RecordMap recordMap;
// A weak map used as a set of cross-zone wrappers. This is used for both
// finalization registries and weak refs. For the former it has wrappers to
// finalization record objects and for the latter wrappers to weak refs.
//
// The weak map marking rules keep the wrappers alive while their targets are
// alive and ensure that they are both swept in the same sweep group.
using WrapperWeakSet = ObjectValueWeakMap;
WrapperWeakSet crossZoneRecords;
// A map of weak ref targets to a vector of weak refs that are observing the
// target. The weak refs may be in other zones and are wrapped appropriately.
using WeakRefHeapPtrVector =
GCVector<js::HeapPtr<JSObject*>, 1, js::ZoneAllocPolicy>;
using WeakRefMap =
GCHashMap<HeapPtr<JSObject*>, WeakRefHeapPtrVector,
StableCellHasher<HeapPtr<JSObject*>>, ZoneAllocPolicy>;
WeakRefMap weakRefMap;
// A weak map used as a set of cross-zone weak refs wrappers.
WrapperWeakSet crossZoneWeakRefs;
public:
explicit FinalizationObservers(Zone* zone);
~FinalizationObservers();
// FinalizationRegistry support:
bool addRegistry(Handle<FinalizationRegistryObject*> registry);
bool addRecord(HandleObject target, HandleObject record);
void clearRecords();
void updateForRemovedRecord(JSObject* wrapper,
FinalizationRecordObject* record);
// WeakRef support:
bool addWeakRefTarget(Handle<JSObject*> target, Handle<JSObject*> weakRef);
void removeWeakRefTarget(Handle<JSObject*> target,
Handle<WeakRefObject*> weakRef);
void unregisterWeakRefWrapper(JSObject* wrapper, WeakRefObject* weakRef);
void traceRoots(JSTracer* trc);
void traceWeakEdges(JSTracer* trc);
#ifdef DEBUG
void checkTables() const;
#endif
private:
bool addCrossZoneWrapper(WrapperWeakSet& weakSet, JSObject* wrapper);
void removeCrossZoneWrapper(WrapperWeakSet& weakSet, JSObject* wrapper);
void updateForRemovedWeakRef(JSObject* wrapper, WeakRefObject* weakRef);
void traceWeakFinalizationRegistryEdges(JSTracer* trc);
void traceWeakWeakRefEdges(JSTracer* trc);
void traceWeakWeakRefVector(JSTracer* trc, WeakRefHeapPtrVector& weakRefs,
JSObject* target);
static bool shouldRemoveRecord(FinalizationRecordObject* record);
};
// Per-global data structures to support FinalizationRegistry.
class FinalizationRegistryGlobalData {
// Set of finalization records for finalization registries in this
// realm. These are traced as part of the realm's global.
using RecordSet =
GCHashSet<HeapPtr<JSObject*>, StableCellHasher<HeapPtr<JSObject*>>,
ZoneAllocPolicy>;
RecordSet recordSet;
public:
explicit FinalizationRegistryGlobalData(Zone* zone);
bool addRecord(FinalizationRecordObject* record);
void removeRecord(FinalizationRecordObject* record);
void trace(JSTracer* trc);
};
} // namespace gc
} // namespace js
#endif // gc_FinalizationObservers_h
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