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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
#include "gc/WeakMap-inl.h"
#include <string.h>
#include "gc/PublicIterators.h"
#include "vm/JSObject.h"
#include "gc/Marking-inl.h"
using namespace js;
using namespace js::gc;
WeakMapBase::WeakMapBase(JSObject* memOf, Zone* zone)
: memberOf(memOf), zone_(zone) {
MOZ_ASSERT_IF(memberOf, memberOf->compartment()->zone() == zone);
MOZ_ASSERT(!IsMarked(mapColor()));
}
WeakMapBase::~WeakMapBase() {
MOZ_ASSERT(CurrentThreadIsGCFinalizing() ||
CurrentThreadCanAccessZone(zone_));
}
void WeakMapBase::unmarkZone(JS::Zone* zone) {
AutoEnterOOMUnsafeRegion oomUnsafe;
if (!zone->gcEphemeronEdges().clear()) {
oomUnsafe.crash("clearing ephemeron edges table");
}
MOZ_ASSERT(zone->gcNurseryEphemeronEdges().count() == 0);
for (WeakMapBase* m : zone->gcWeakMapList()) {
m->setMapColor(CellColor::White);
}
}
void Zone::traceWeakMaps(JSTracer* trc) {
MOZ_ASSERT(trc->weakMapAction() != JS::WeakMapTraceAction::Skip);
for (WeakMapBase* m : gcWeakMapList()) {
m->trace(trc);
TraceNullableEdge(trc, &m->memberOf, "memberOf");
}
}
bool WeakMapBase::markMap(MarkColor markColor) {
// We may be marking in parallel here so use a compare exchange loop to handle
// concurrent updates to the map color.
//
// The color increases monotonically; we don't downgrade from black to gray.
//
// We can attempt to mark gray after marking black when a barrier pushes the
// map object onto the black mark stack when it's already present on the
// gray mark stack, since this is marked later.
uint32_t targetColor = uint32_t(markColor);
for (;;) {
uint32_t currentColor = mapColor_;
if (currentColor >= targetColor) {
return false;
}
if (mapColor_.compareExchange(currentColor, targetColor)) {
return true;
}
}
}
bool WeakMapBase::addEphemeronEdgesForEntry(MarkColor mapColor, Cell* key,
Cell* delegate,
TenuredCell* value) {
if (delegate && !addEphemeronEdge(mapColor, delegate, key)) {
return false;
}
if (value && !addEphemeronEdge(mapColor, key, value)) {
return false;
}
return true;
}
bool WeakMapBase::addEphemeronEdge(MarkColor color, gc::Cell* src,
gc::Cell* dst) {
// Add an implicit edge from |src| to |dst|.
auto& edgeTable = src->zone()->gcEphemeronEdges(src);
auto* ptr = edgeTable.getOrAdd(src);
return ptr && ptr->value.emplaceBack(color, dst);
}
#if defined(JS_GC_ZEAL) || defined(DEBUG)
bool WeakMapBase::checkMarkingForZone(JS::Zone* zone) {
// This is called at the end of marking.
MOZ_ASSERT(zone->isGCMarking());
bool ok = true;
for (WeakMapBase* m : zone->gcWeakMapList()) {
if (IsMarked(m->mapColor()) && !m->checkMarking()) {
ok = false;
}
}
return ok;
}
#endif
bool WeakMapBase::markZoneIteratively(JS::Zone* zone, GCMarker* marker) {
bool markedAny = false;
for (WeakMapBase* m : zone->gcWeakMapList()) {
if (IsMarked(m->mapColor()) && m->markEntries(marker)) {
markedAny = true;
}
}
return markedAny;
}
bool WeakMapBase::findSweepGroupEdgesForZone(JS::Zone* zone) {
for (WeakMapBase* m : zone->gcWeakMapList()) {
if (!m->findSweepGroupEdges()) {
return false;
}
}
return true;
}
void Zone::sweepWeakMaps(JSTracer* trc) {
for (WeakMapBase* m = gcWeakMapList().getFirst(); m;) {
WeakMapBase* next = m->getNext();
if (IsMarked(m->mapColor())) {
m->traceWeakEdges(trc);
} else {
m->clearAndCompact();
m->removeFrom(gcWeakMapList());
}
m = next;
}
#ifdef DEBUG
for (WeakMapBase* m : gcWeakMapList()) {
MOZ_ASSERT(m->isInList() && IsMarked(m->mapColor()));
}
#endif
}
void WeakMapBase::traceAllMappings(WeakMapTracer* tracer) {
JSRuntime* rt = tracer->runtime;
for (ZonesIter zone(rt, SkipAtoms); !zone.done(); zone.next()) {
for (WeakMapBase* m : zone->gcWeakMapList()) {
// The WeakMapTracer callback is not allowed to GC.
JS::AutoSuppressGCAnalysis nogc;
m->traceMappings(tracer);
}
}
}
bool WeakMapBase::saveZoneMarkedWeakMaps(JS::Zone* zone,
WeakMapColors& markedWeakMaps) {
for (WeakMapBase* m : zone->gcWeakMapList()) {
if (IsMarked(m->mapColor()) && !markedWeakMaps.put(m, m->mapColor())) {
return false;
}
}
return true;
}
void WeakMapBase::restoreMarkedWeakMaps(WeakMapColors& markedWeakMaps) {
for (WeakMapColors::Range r = markedWeakMaps.all(); !r.empty();
r.popFront()) {
WeakMapBase* map = r.front().key();
MOZ_ASSERT(map->zone()->isGCMarking());
MOZ_ASSERT(!IsMarked(map->mapColor()));
map->setMapColor(r.front().value());
}
}
ObjectWeakMap::ObjectWeakMap(JSContext* cx) : map(cx, nullptr) {}
JSObject* ObjectWeakMap::lookup(const JSObject* obj) {
if (ObjectValueWeakMap::Ptr p = map.lookup(const_cast<JSObject*>(obj))) {
return &p->value().toObject();
}
return nullptr;
}
bool ObjectWeakMap::add(JSContext* cx, JSObject* obj, JSObject* target) {
MOZ_ASSERT(obj && target);
Value targetVal(ObjectValue(*target));
if (!map.putNew(obj, targetVal)) {
ReportOutOfMemory(cx);
return false;
}
return true;
}
void ObjectWeakMap::remove(JSObject* key) {
MOZ_ASSERT(key);
map.remove(key);
}
void ObjectWeakMap::clear() { map.clear(); }
void ObjectWeakMap::trace(JSTracer* trc) { map.trace(trc); }
size_t ObjectWeakMap::sizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) {
return map.shallowSizeOfExcludingThis(mallocSizeOf);
}
#ifdef JSGC_HASH_TABLE_CHECKS
void ObjectWeakMap::checkAfterMovingGC() {
for (ObjectValueWeakMap::Range r = map.all(); !r.empty(); r.popFront()) {
CheckGCThingAfterMovingGC(r.front().key().get());
CheckGCThingAfterMovingGC(&r.front().value().toObject());
}
}
#endif // JSGC_HASH_TABLE_CHECKS