https://github.com/mozilla/gecko-dev
Tip revision: 3e8d54196120f1fbe4171b342c1aaf2cb2cb45b1 authored by ffxbld on 29 October 2015, 22:10:37 UTC
Added FIREFOX_42_0_RELEASE FIREFOX_42_0_BUILD2 tag(s) for changeset e2f9a0ed50bc. DONTBUILD CLOSED TREE a=release
Added FIREFOX_42_0_RELEASE FIREFOX_42_0_BUILD2 tag(s) for changeset e2f9a0ed50bc. DONTBUILD CLOSED TREE a=release
Tip revision: 3e8d541
jsweakmap.cpp
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* vim: set ts=8 sts=4 et sw=4 tw=99:
* 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/. */
#include "jsweakmap.h"
#include <string.h>
#include "jsapi.h"
#include "jscntxt.h"
#include "jsfriendapi.h"
#include "jsobj.h"
#include "jswrapper.h"
#include "js/GCAPI.h"
#include "vm/GlobalObject.h"
#include "vm/WeakMapObject.h"
#include "jsobjinlines.h"
#include "vm/Interpreter-inl.h"
#include "vm/NativeObject-inl.h"
using namespace js;
using namespace js::gc;
using mozilla::UniquePtr;
WeakMapBase::WeakMapBase(JSObject* memOf, JSCompartment* c)
: memberOf(memOf),
compartment(c),
next(WeakMapNotInList),
marked(false)
{
MOZ_ASSERT_IF(memberOf, memberOf->compartment() == c);
}
WeakMapBase::~WeakMapBase()
{
MOZ_ASSERT(CurrentThreadIsGCSweeping() || CurrentThreadIsHandlingInitFailure());
MOZ_ASSERT_IF(CurrentThreadIsGCSweeping(), !isInList());
if (isInList())
removeWeakMapFromList(this);
}
void
WeakMapBase::trace(JSTracer* tracer)
{
MOZ_ASSERT(isInList());
if (tracer->isMarkingTracer()) {
// We don't trace any of the WeakMap entries at this time, just record
// record the fact that the WeakMap has been marked. Entries are marked
// in the iterative marking phase by markAllIteratively(), which happens
// when as many keys as possible have been marked already.
MOZ_ASSERT(tracer->eagerlyTraceWeakMaps() == DoNotTraceWeakMaps);
marked = true;
} else {
// If we're not actually doing garbage collection, the keys won't be marked
// nicely as needed by the true ephemeral marking algorithm --- custom tracers
// such as the cycle collector must use their own means for cycle detection.
// So here we do a conservative approximation: pretend all keys are live.
if (tracer->eagerlyTraceWeakMaps() == DoNotTraceWeakMaps)
return;
nonMarkingTraceValues(tracer);
if (tracer->eagerlyTraceWeakMaps() == TraceWeakMapKeysValues)
nonMarkingTraceKeys(tracer);
}
}
void
WeakMapBase::unmarkCompartment(JSCompartment* c)
{
for (WeakMapBase* m = c->gcWeakMapList; m; m = m->next)
m->marked = false;
}
void
WeakMapBase::markAll(JSCompartment* c, JSTracer* tracer)
{
MOZ_ASSERT(tracer->eagerlyTraceWeakMaps() != DoNotTraceWeakMaps);
for (WeakMapBase* m = c->gcWeakMapList; m; m = m->next) {
m->trace(tracer);
if (m->memberOf)
TraceEdge(tracer, &m->memberOf, "memberOf");
}
}
bool
WeakMapBase::markCompartmentIteratively(JSCompartment* c, JSTracer* tracer)
{
bool markedAny = false;
for (WeakMapBase* m = c->gcWeakMapList; m; m = m->next) {
if (m->marked && m->markIteratively(tracer))
markedAny = true;
}
return markedAny;
}
bool
WeakMapBase::findZoneEdgesForCompartment(JSCompartment* c)
{
for (WeakMapBase* m = c->gcWeakMapList; m; m = m->next) {
if (!m->findZoneEdges())
return false;
}
return true;
}
void
WeakMapBase::sweepCompartment(JSCompartment* c)
{
WeakMapBase** tailPtr = &c->gcWeakMapList;
for (WeakMapBase* m = c->gcWeakMapList; m; ) {
WeakMapBase* next = m->next;
if (m->marked) {
m->sweep();
*tailPtr = m;
tailPtr = &m->next;
} else {
/* Destroy the hash map now to catch any use after this point. */
m->finish();
m->next = WeakMapNotInList;
}
m = next;
}
*tailPtr = nullptr;
#ifdef DEBUG
for (WeakMapBase* m = c->gcWeakMapList; m; m = m->next)
MOZ_ASSERT(m->isInList() && m->marked);
#endif
}
void
WeakMapBase::traceAllMappings(WeakMapTracer* tracer)
{
JSRuntime* rt = tracer->runtime;
for (CompartmentsIter c(rt, SkipAtoms); !c.done(); c.next()) {
for (WeakMapBase* m = c->gcWeakMapList; m; m = m->next) {
// The WeakMapTracer callback is not allowed to GC.
JS::AutoSuppressGCAnalysis nogc;
m->traceMappings(tracer);
}
}
}
bool
WeakMapBase::saveCompartmentMarkedWeakMaps(JSCompartment* c, WeakMapSet& markedWeakMaps)
{
for (WeakMapBase* m = c->gcWeakMapList; m; m = m->next) {
if (m->marked && !markedWeakMaps.put(m))
return false;
}
return true;
}
void
WeakMapBase::restoreCompartmentMarkedWeakMaps(WeakMapSet& markedWeakMaps)
{
for (WeakMapSet::Range r = markedWeakMaps.all(); !r.empty(); r.popFront()) {
WeakMapBase* map = r.front();
MOZ_ASSERT(map->compartment->zone()->isGCMarking());
MOZ_ASSERT(!map->marked);
map->marked = true;
}
}
void
WeakMapBase::removeWeakMapFromList(WeakMapBase* weakmap)
{
JSCompartment* c = weakmap->compartment;
for (WeakMapBase** p = &c->gcWeakMapList; *p; p = &(*p)->next) {
if (*p == weakmap) {
*p = (*p)->next;
weakmap->next = WeakMapNotInList;
break;
}
}
}
bool
ObjectValueMap::findZoneEdges()
{
/*
* For unmarked weakmap keys with delegates in a different zone, add a zone
* edge to ensure that the delegate zone does finish marking after the key
* zone.
*/
JS::AutoSuppressGCAnalysis nogc;
Zone* mapZone = compartment->zone();
for (Range r = all(); !r.empty(); r.popFront()) {
JSObject* key = r.front().key();
if (key->asTenured().isMarked(BLACK) && !key->asTenured().isMarked(GRAY))
continue;
JSWeakmapKeyDelegateOp op = key->getClass()->ext.weakmapKeyDelegateOp;
if (!op)
continue;
JSObject* delegate = op(key);
if (!delegate)
continue;
Zone* delegateZone = delegate->zone();
if (delegateZone == mapZone)
continue;
if (!delegateZone->gcZoneGroupEdges.put(key->zone()))
return false;
}
return true;
}
MOZ_ALWAYS_INLINE bool
IsWeakMap(HandleValue v)
{
return v.isObject() && v.toObject().is<WeakMapObject>();
}
MOZ_ALWAYS_INLINE bool
WeakMap_has_impl(JSContext* cx, CallArgs args)
{
MOZ_ASSERT(IsWeakMap(args.thisv()));
if (!args.get(0).isObject()) {
args.rval().setBoolean(false);
return true;
}
if (ObjectValueMap* map = args.thisv().toObject().as<WeakMapObject>().getMap()) {
JSObject* key = &args[0].toObject();
if (map->has(key)) {
args.rval().setBoolean(true);
return true;
}
}
args.rval().setBoolean(false);
return true;
}
bool
js::WeakMap_has(JSContext* cx, unsigned argc, Value* vp)
{
CallArgs args = CallArgsFromVp(argc, vp);
return CallNonGenericMethod<IsWeakMap, WeakMap_has_impl>(cx, args);
}
MOZ_ALWAYS_INLINE bool
WeakMap_clear_impl(JSContext* cx, CallArgs args)
{
MOZ_ASSERT(IsWeakMap(args.thisv()));
// We can't js_delete the weakmap because the data gathered during GC is
// used by the Cycle Collector.
if (ObjectValueMap* map = args.thisv().toObject().as<WeakMapObject>().getMap())
map->clear();
args.rval().setUndefined();
return true;
}
bool
js::WeakMap_clear(JSContext* cx, unsigned argc, Value* vp)
{
CallArgs args = CallArgsFromVp(argc, vp);
return CallNonGenericMethod<IsWeakMap, WeakMap_clear_impl>(cx, args);
}
MOZ_ALWAYS_INLINE bool
WeakMap_get_impl(JSContext* cx, CallArgs args)
{
MOZ_ASSERT(IsWeakMap(args.thisv()));
if (!args.get(0).isObject()) {
args.rval().setUndefined();
return true;
}
if (ObjectValueMap* map = args.thisv().toObject().as<WeakMapObject>().getMap()) {
JSObject* key = &args[0].toObject();
if (ObjectValueMap::Ptr ptr = map->lookup(key)) {
args.rval().set(ptr->value());
return true;
}
}
args.rval().setUndefined();
return true;
}
bool
js::WeakMap_get(JSContext* cx, unsigned argc, Value* vp)
{
CallArgs args = CallArgsFromVp(argc, vp);
return CallNonGenericMethod<IsWeakMap, WeakMap_get_impl>(cx, args);
}
MOZ_ALWAYS_INLINE bool
WeakMap_delete_impl(JSContext* cx, CallArgs args)
{
MOZ_ASSERT(IsWeakMap(args.thisv()));
if (!args.get(0).isObject()) {
args.rval().setBoolean(false);
return true;
}
if (ObjectValueMap* map = args.thisv().toObject().as<WeakMapObject>().getMap()) {
JSObject* key = &args[0].toObject();
if (ObjectValueMap::Ptr ptr = map->lookup(key)) {
map->remove(ptr);
args.rval().setBoolean(true);
return true;
}
}
args.rval().setBoolean(false);
return true;
}
bool
js::WeakMap_delete(JSContext* cx, unsigned argc, Value* vp)
{
CallArgs args = CallArgsFromVp(argc, vp);
return CallNonGenericMethod<IsWeakMap, WeakMap_delete_impl>(cx, args);
}
static bool
TryPreserveReflector(JSContext* cx, HandleObject obj)
{
if (obj->getClass()->ext.isWrappedNative ||
(obj->getClass()->flags & JSCLASS_IS_DOMJSCLASS) ||
(obj->is<ProxyObject>() &&
obj->as<ProxyObject>().handler()->family() == GetDOMProxyHandlerFamily()))
{
MOZ_ASSERT(cx->runtime()->preserveWrapperCallback);
if (!cx->runtime()->preserveWrapperCallback(cx, obj)) {
JS_ReportErrorNumber(cx, GetErrorMessage, nullptr, JSMSG_BAD_WEAKMAP_KEY);
return false;
}
}
return true;
}
static inline void
WeakMapPostWriteBarrier(JSRuntime* rt, ObjectValueMap* weakMap, JSObject* key)
{
if (key && IsInsideNursery(key))
rt->gc.storeBuffer.putGeneric(gc::HashKeyRef<ObjectValueMap, JSObject*>(weakMap, key));
}
static MOZ_ALWAYS_INLINE bool
SetWeakMapEntryInternal(JSContext* cx, Handle<WeakMapObject*> mapObj,
HandleObject key, HandleValue value)
{
ObjectValueMap* map = mapObj->getMap();
if (!map) {
map = cx->new_<ObjectValueMap>(cx, mapObj.get());
if (!map)
return false;
if (!map->init()) {
js_delete(map);
JS_ReportOutOfMemory(cx);
return false;
}
mapObj->setPrivate(map);
}
// Preserve wrapped native keys to prevent wrapper optimization.
if (!TryPreserveReflector(cx, key))
return false;
if (JSWeakmapKeyDelegateOp op = key->getClass()->ext.weakmapKeyDelegateOp) {
RootedObject delegate(cx, op(key));
if (delegate && !TryPreserveReflector(cx, delegate))
return false;
}
MOZ_ASSERT(key->compartment() == mapObj->compartment());
MOZ_ASSERT_IF(value.isObject(), value.toObject().compartment() == mapObj->compartment());
if (!map->put(key, value)) {
JS_ReportOutOfMemory(cx);
return false;
}
WeakMapPostWriteBarrier(cx->runtime(), map, key.get());
return true;
}
MOZ_ALWAYS_INLINE bool
WeakMap_set_impl(JSContext* cx, CallArgs args)
{
MOZ_ASSERT(IsWeakMap(args.thisv()));
if (!args.get(0).isObject()) {
UniquePtr<char[], JS::FreePolicy> bytes =
DecompileValueGenerator(cx, JSDVG_SEARCH_STACK, args.get(0), nullptr);
if (!bytes)
return false;
JS_ReportErrorNumber(cx, GetErrorMessage, nullptr, JSMSG_NOT_NONNULL_OBJECT, bytes.get());
return false;
}
RootedObject key(cx, &args[0].toObject());
Rooted<JSObject*> thisObj(cx, &args.thisv().toObject());
Rooted<WeakMapObject*> map(cx, &thisObj->as<WeakMapObject>());
if (!SetWeakMapEntryInternal(cx, map, key, args.get(1)))
return false;
args.rval().set(args.thisv());
return true;
}
bool
js::WeakMap_set(JSContext* cx, unsigned argc, Value* vp)
{
CallArgs args = CallArgsFromVp(argc, vp);
return CallNonGenericMethod<IsWeakMap, WeakMap_set_impl>(cx, args);
}
JS_FRIEND_API(bool)
JS_NondeterministicGetWeakMapKeys(JSContext* cx, HandleObject objArg, MutableHandleObject ret)
{
RootedObject obj(cx, objArg);
obj = UncheckedUnwrap(obj);
if (!obj || !obj->is<WeakMapObject>()) {
ret.set(nullptr);
return true;
}
RootedObject arr(cx, NewDenseEmptyArray(cx));
if (!arr)
return false;
ObjectValueMap* map = obj->as<WeakMapObject>().getMap();
if (map) {
// Prevent GC from mutating the weakmap while iterating.
AutoSuppressGC suppress(cx);
for (ObjectValueMap::Base::Range r = map->all(); !r.empty(); r.popFront()) {
JS::ExposeObjectToActiveJS(r.front().key());
RootedObject key(cx, r.front().key());
if (!cx->compartment()->wrap(cx, &key))
return false;
if (!NewbornArrayPush(cx, arr, ObjectValue(*key)))
return false;
}
}
ret.set(arr);
return true;
}
static void
WeakMap_mark(JSTracer* trc, JSObject* obj)
{
if (ObjectValueMap* map = obj->as<WeakMapObject>().getMap())
map->trace(trc);
}
static void
WeakMap_finalize(FreeOp* fop, JSObject* obj)
{
if (ObjectValueMap* map = obj->as<WeakMapObject>().getMap()) {
#ifdef DEBUG
map->~ObjectValueMap();
memset(static_cast<void*>(map), 0xdc, sizeof(*map));
fop->free_(map);
#else
fop->delete_(map);
#endif
}
}
JS_PUBLIC_API(JSObject*)
JS::NewWeakMapObject(JSContext* cx)
{
return NewBuiltinClassInstance(cx, &WeakMapObject::class_);
}
JS_PUBLIC_API(bool)
JS::IsWeakMapObject(JSObject* obj)
{
return obj->is<WeakMapObject>();
}
JS_PUBLIC_API(bool)
JS::GetWeakMapEntry(JSContext* cx, HandleObject mapObj, HandleObject key,
MutableHandleValue rval)
{
CHECK_REQUEST(cx);
assertSameCompartment(cx, key);
rval.setUndefined();
ObjectValueMap* map = mapObj->as<WeakMapObject>().getMap();
if (!map)
return true;
if (ObjectValueMap::Ptr ptr = map->lookup(key)) {
// Read barrier to prevent an incorrectly gray value from escaping the
// weak map. See the comment before UnmarkGrayChildren in gc/Marking.cpp
ExposeValueToActiveJS(ptr->value().get());
rval.set(ptr->value());
}
return true;
}
JS_PUBLIC_API(bool)
JS::SetWeakMapEntry(JSContext* cx, HandleObject mapObj, HandleObject key,
HandleValue val)
{
CHECK_REQUEST(cx);
assertSameCompartment(cx, key, val);
Rooted<WeakMapObject*> rootedMap(cx, &mapObj->as<WeakMapObject>());
return SetWeakMapEntryInternal(cx, rootedMap, key, val);
}
static bool
WeakMap_construct(JSContext* cx, unsigned argc, Value* vp)
{
CallArgs args = CallArgsFromVp(argc, vp);
// ES6 draft rev 31 (15 Jan 2015) 23.3.1.1 step 1.
if (!ThrowIfNotConstructing(cx, args, "WeakMap"))
return false;
RootedObject obj(cx, NewBuiltinClassInstance(cx, &WeakMapObject::class_));
if (!obj)
return false;
// Steps 5-6, 11.
if (!args.get(0).isNullOrUndefined()) {
// Steps 7a-b.
RootedValue adderVal(cx);
if (!GetProperty(cx, obj, obj, cx->names().set, &adderVal))
return false;
// Step 7c.
if (!IsCallable(adderVal))
return ReportIsNotFunction(cx, adderVal);
bool isOriginalAdder = IsNativeFunction(adderVal, WeakMap_set);
RootedValue mapVal(cx, ObjectValue(*obj));
FastInvokeGuard fig(cx, adderVal);
InvokeArgs& args2 = fig.args();
// Steps 7d-e.
JS::ForOfIterator iter(cx);
if (!iter.init(args[0]))
return false;
RootedValue pairVal(cx);
RootedObject pairObject(cx);
RootedValue keyVal(cx);
RootedObject keyObject(cx);
RootedValue val(cx);
while (true) {
// Steps 12a-e.
bool done;
if (!iter.next(&pairVal, &done))
return false;
if (done)
break;
// Step 12f.
if (!pairVal.isObject()) {
JS_ReportErrorNumber(cx, GetErrorMessage, nullptr,
JSMSG_INVALID_MAP_ITERABLE, "WeakMap");
return false;
}
pairObject = &pairVal.toObject();
if (!pairObject)
return false;
// Steps 12g-h.
if (!GetElement(cx, pairObject, pairObject, 0, &keyVal))
return false;
// Steps 12i-j.
if (!GetElement(cx, pairObject, pairObject, 1, &val))
return false;
// Steps 12k-l.
if (isOriginalAdder) {
if (keyVal.isPrimitive()) {
UniquePtr<char[], JS::FreePolicy> bytes =
DecompileValueGenerator(cx, JSDVG_SEARCH_STACK, keyVal, nullptr);
if (!bytes)
return false;
JS_ReportErrorNumber(cx, GetErrorMessage, nullptr, JSMSG_NOT_NONNULL_OBJECT, bytes.get());
return false;
}
keyObject = &keyVal.toObject();
if (!SetWeakMapEntry(cx, obj, keyObject, val))
return false;
} else {
if (!args2.init(2))
return false;
args2.setCallee(adderVal);
args2.setThis(mapVal);
args2[0].set(keyVal);
args2[1].set(val);
if (!fig.invoke(cx))
return false;
}
}
}
args.rval().setObject(*obj);
return true;
}
const Class WeakMapObject::class_ = {
"WeakMap",
JSCLASS_HAS_PRIVATE | JSCLASS_IMPLEMENTS_BARRIERS |
JSCLASS_HAS_CACHED_PROTO(JSProto_WeakMap),
nullptr, /* addProperty */
nullptr, /* delProperty */
nullptr, /* getProperty */
nullptr, /* setProperty */
nullptr, /* enumerate */
nullptr, /* resolve */
nullptr, /* mayResolve */
nullptr, /* convert */
WeakMap_finalize,
nullptr, /* call */
nullptr, /* hasInstance */
nullptr, /* construct */
WeakMap_mark
};
static const JSFunctionSpec weak_map_methods[] = {
JS_FN("has", WeakMap_has, 1, 0),
JS_FN("get", WeakMap_get, 1, 0),
JS_FN("delete", WeakMap_delete, 1, 0),
JS_FN("set", WeakMap_set, 2, 0),
JS_FN("clear", WeakMap_clear, 0, 0),
JS_FS_END
};
static JSObject*
InitWeakMapClass(JSContext* cx, HandleObject obj, bool defineMembers)
{
MOZ_ASSERT(obj->isNative());
Rooted<GlobalObject*> global(cx, &obj->as<GlobalObject>());
RootedPlainObject proto(cx, NewBuiltinClassInstance<PlainObject>(cx));
if (!proto)
return nullptr;
RootedFunction ctor(cx, global->createConstructor(cx, WeakMap_construct,
cx->names().WeakMap, 0));
if (!ctor)
return nullptr;
if (!LinkConstructorAndPrototype(cx, ctor, proto))
return nullptr;
if (defineMembers) {
if (!DefinePropertiesAndFunctions(cx, proto, nullptr, weak_map_methods))
return nullptr;
}
if (!GlobalObject::initBuiltinConstructor(cx, global, JSProto_WeakMap, ctor, proto))
return nullptr;
return proto;
}
JSObject*
js::InitWeakMapClass(JSContext* cx, HandleObject obj)
{
return InitWeakMapClass(cx, obj, true);
}
JSObject*
js::InitBareWeakMapCtor(JSContext* cx, HandleObject obj)
{
return InitWeakMapClass(cx, obj, false);
}
ObjectWeakMap::ObjectWeakMap(JSContext* cx)
: map(cx, nullptr)
{
if (!map.init())
CrashAtUnhandlableOOM("ObjectWeakMap");
}
ObjectWeakMap::~ObjectWeakMap()
{
WeakMapBase::removeWeakMapFromList(&map);
}
JSObject*
ObjectWeakMap::lookup(const JSObject* obj)
{
if (ObjectValueMap::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);
MOZ_ASSERT(!map.has(obj));
if (!map.put(obj, ObjectValue(*target))) {
ReportOutOfMemory(cx);
return false;
}
if (IsInsideNursery(obj))
cx->runtime()->gc.storeBuffer.putGeneric(StoreBufferRef(&map, obj));
return true;
}
void
ObjectWeakMap::clear()
{
map.clear();
}
void
ObjectWeakMap::trace(JSTracer* trc)
{
map.trace(trc);
}
size_t
ObjectWeakMap::sizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf)
{
return map.sizeOfExcludingThis(mallocSizeOf);
}
#ifdef JSGC_HASH_TABLE_CHECKS
void
ObjectWeakMap::checkAfterMovingGC()
{
for (ObjectValueMap::Range r = map.all(); !r.empty(); r.popFront()) {
CheckGCThingAfterMovingGC(r.front().key().get());
CheckGCThingAfterMovingGC(&r.front().value().toObject());
}
}
#endif // JSGC_HASH_TABLE_CHECKS