1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/js/src/jsweakmap.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,517 @@
1.4 +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
1.5 + * vim: set ts=8 sts=4 et sw=4 tw=99:
1.6 + * This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +#include "jsweakmap.h"
1.11 +
1.12 +#include <string.h>
1.13 +
1.14 +#include "jsapi.h"
1.15 +#include "jscntxt.h"
1.16 +#include "jsfriendapi.h"
1.17 +#include "jsobj.h"
1.18 +#include "jswrapper.h"
1.19 +
1.20 +#include "vm/GlobalObject.h"
1.21 +#include "vm/WeakMapObject.h"
1.22 +
1.23 +#include "jsobjinlines.h"
1.24 +
1.25 +using namespace js;
1.26 +
1.27 +WeakMapBase::WeakMapBase(JSObject *memOf, JSCompartment *c)
1.28 + : memberOf(memOf),
1.29 + compartment(c),
1.30 + next(WeakMapNotInList)
1.31 +{
1.32 + JS_ASSERT_IF(memberOf, memberOf->compartment() == c);
1.33 +}
1.34 +
1.35 +WeakMapBase::~WeakMapBase()
1.36 +{
1.37 + JS_ASSERT(next == WeakMapNotInList);
1.38 +}
1.39 +
1.40 +bool
1.41 +WeakMapBase::markCompartmentIteratively(JSCompartment *c, JSTracer *tracer)
1.42 +{
1.43 + bool markedAny = false;
1.44 + for (WeakMapBase *m = c->gcWeakMapList; m; m = m->next) {
1.45 + if (m->markIteratively(tracer))
1.46 + markedAny = true;
1.47 + }
1.48 + return markedAny;
1.49 +}
1.50 +
1.51 +void
1.52 +WeakMapBase::sweepCompartment(JSCompartment *c)
1.53 +{
1.54 + for (WeakMapBase *m = c->gcWeakMapList; m; m = m->next)
1.55 + m->sweep();
1.56 +}
1.57 +
1.58 +void
1.59 +WeakMapBase::traceAllMappings(WeakMapTracer *tracer)
1.60 +{
1.61 + JSRuntime *rt = tracer->runtime;
1.62 + for (CompartmentsIter c(rt, SkipAtoms); !c.done(); c.next()) {
1.63 + for (WeakMapBase *m = c->gcWeakMapList; m; m = m->next)
1.64 + m->traceMappings(tracer);
1.65 + }
1.66 +}
1.67 +
1.68 +void
1.69 +WeakMapBase::resetCompartmentWeakMapList(JSCompartment *c)
1.70 +{
1.71 + JS_ASSERT(WeakMapNotInList != nullptr);
1.72 +
1.73 + WeakMapBase *m = c->gcWeakMapList;
1.74 + c->gcWeakMapList = nullptr;
1.75 + while (m) {
1.76 + WeakMapBase *n = m->next;
1.77 + m->next = WeakMapNotInList;
1.78 + m = n;
1.79 + }
1.80 +}
1.81 +
1.82 +bool
1.83 +WeakMapBase::saveCompartmentWeakMapList(JSCompartment *c, WeakMapVector &vector)
1.84 +{
1.85 + WeakMapBase *m = c->gcWeakMapList;
1.86 + while (m) {
1.87 + if (!vector.append(m))
1.88 + return false;
1.89 + m = m->next;
1.90 + }
1.91 + return true;
1.92 +}
1.93 +
1.94 +void
1.95 +WeakMapBase::restoreCompartmentWeakMapLists(WeakMapVector &vector)
1.96 +{
1.97 + for (WeakMapBase **p = vector.begin(); p != vector.end(); p++) {
1.98 + WeakMapBase *m = *p;
1.99 + JS_ASSERT(m->next == WeakMapNotInList);
1.100 + JSCompartment *c = m->compartment;
1.101 + m->next = c->gcWeakMapList;
1.102 + c->gcWeakMapList = m;
1.103 + }
1.104 +}
1.105 +
1.106 +void
1.107 +WeakMapBase::removeWeakMapFromList(WeakMapBase *weakmap)
1.108 +{
1.109 + JSCompartment *c = weakmap->compartment;
1.110 + for (WeakMapBase **p = &c->gcWeakMapList; *p; p = &(*p)->next) {
1.111 + if (*p == weakmap) {
1.112 + *p = (*p)->next;
1.113 + weakmap->next = WeakMapNotInList;
1.114 + break;
1.115 + }
1.116 + }
1.117 +}
1.118 +
1.119 +static JSObject *
1.120 +GetKeyArg(JSContext *cx, CallArgs &args)
1.121 +{
1.122 + if (args[0].isPrimitive()) {
1.123 + JS_ReportErrorNumber(cx, js_GetErrorMessage, nullptr, JSMSG_NOT_NONNULL_OBJECT);
1.124 + return nullptr;
1.125 + }
1.126 + return &args[0].toObject();
1.127 +}
1.128 +
1.129 +MOZ_ALWAYS_INLINE bool
1.130 +IsWeakMap(HandleValue v)
1.131 +{
1.132 + return v.isObject() && v.toObject().is<WeakMapObject>();
1.133 +}
1.134 +
1.135 +MOZ_ALWAYS_INLINE bool
1.136 +WeakMap_has_impl(JSContext *cx, CallArgs args)
1.137 +{
1.138 + JS_ASSERT(IsWeakMap(args.thisv()));
1.139 +
1.140 + if (args.length() < 1) {
1.141 + JS_ReportErrorNumber(cx, js_GetErrorMessage, nullptr, JSMSG_MORE_ARGS_NEEDED,
1.142 + "WeakMap.has", "0", "s");
1.143 + return false;
1.144 + }
1.145 + JSObject *key = GetKeyArg(cx, args);
1.146 + if (!key)
1.147 + return false;
1.148 +
1.149 + if (ObjectValueMap *map = args.thisv().toObject().as<WeakMapObject>().getMap()) {
1.150 + if (map->has(key)) {
1.151 + args.rval().setBoolean(true);
1.152 + return true;
1.153 + }
1.154 + }
1.155 +
1.156 + args.rval().setBoolean(false);
1.157 + return true;
1.158 +}
1.159 +
1.160 +static bool
1.161 +WeakMap_has(JSContext *cx, unsigned argc, Value *vp)
1.162 +{
1.163 + CallArgs args = CallArgsFromVp(argc, vp);
1.164 + return CallNonGenericMethod<IsWeakMap, WeakMap_has_impl>(cx, args);
1.165 +}
1.166 +
1.167 +MOZ_ALWAYS_INLINE bool
1.168 +WeakMap_clear_impl(JSContext *cx, CallArgs args)
1.169 +{
1.170 + JS_ASSERT(IsWeakMap(args.thisv()));
1.171 +
1.172 + // We can't js_delete the weakmap because the data gathered during GC
1.173 + // is used by the Cycle Collector
1.174 + if (ObjectValueMap *map = args.thisv().toObject().as<WeakMapObject>().getMap())
1.175 + map->clear();
1.176 +
1.177 + args.rval().setUndefined();
1.178 + return true;
1.179 +}
1.180 +
1.181 +static bool
1.182 +WeakMap_clear(JSContext *cx, unsigned argc, Value *vp)
1.183 +{
1.184 + CallArgs args = CallArgsFromVp(argc, vp);
1.185 + return CallNonGenericMethod<IsWeakMap, WeakMap_clear_impl>(cx, args);
1.186 +}
1.187 +
1.188 +MOZ_ALWAYS_INLINE bool
1.189 +WeakMap_get_impl(JSContext *cx, CallArgs args)
1.190 +{
1.191 + JS_ASSERT(IsWeakMap(args.thisv()));
1.192 +
1.193 + if (args.length() < 1) {
1.194 + JS_ReportErrorNumber(cx, js_GetErrorMessage, nullptr, JSMSG_MORE_ARGS_NEEDED,
1.195 + "WeakMap.get", "0", "s");
1.196 + return false;
1.197 + }
1.198 + JSObject *key = GetKeyArg(cx, args);
1.199 + if (!key)
1.200 + return false;
1.201 +
1.202 + if (ObjectValueMap *map = args.thisv().toObject().as<WeakMapObject>().getMap()) {
1.203 + if (ObjectValueMap::Ptr ptr = map->lookup(key)) {
1.204 + // Read barrier to prevent an incorrectly gray value from escaping the
1.205 + // weak map. See the comment before UnmarkGrayChildren in gc/Marking.cpp
1.206 + ExposeValueToActiveJS(ptr->value().get());
1.207 +
1.208 + args.rval().set(ptr->value());
1.209 + return true;
1.210 + }
1.211 + }
1.212 +
1.213 + args.rval().set((args.length() > 1) ? args[1] : UndefinedValue());
1.214 + return true;
1.215 +}
1.216 +
1.217 +static bool
1.218 +WeakMap_get(JSContext *cx, unsigned argc, Value *vp)
1.219 +{
1.220 + CallArgs args = CallArgsFromVp(argc, vp);
1.221 + return CallNonGenericMethod<IsWeakMap, WeakMap_get_impl>(cx, args);
1.222 +}
1.223 +
1.224 +MOZ_ALWAYS_INLINE bool
1.225 +WeakMap_delete_impl(JSContext *cx, CallArgs args)
1.226 +{
1.227 + JS_ASSERT(IsWeakMap(args.thisv()));
1.228 +
1.229 + if (args.length() < 1) {
1.230 + JS_ReportErrorNumber(cx, js_GetErrorMessage, nullptr, JSMSG_MORE_ARGS_NEEDED,
1.231 + "WeakMap.delete", "0", "s");
1.232 + return false;
1.233 + }
1.234 + JSObject *key = GetKeyArg(cx, args);
1.235 + if (!key)
1.236 + return false;
1.237 +
1.238 + if (ObjectValueMap *map = args.thisv().toObject().as<WeakMapObject>().getMap()) {
1.239 + if (ObjectValueMap::Ptr ptr = map->lookup(key)) {
1.240 + map->remove(ptr);
1.241 + args.rval().setBoolean(true);
1.242 + return true;
1.243 + }
1.244 + }
1.245 +
1.246 + args.rval().setBoolean(false);
1.247 + return true;
1.248 +}
1.249 +
1.250 +static bool
1.251 +WeakMap_delete(JSContext *cx, unsigned argc, Value *vp)
1.252 +{
1.253 + CallArgs args = CallArgsFromVp(argc, vp);
1.254 + return CallNonGenericMethod<IsWeakMap, WeakMap_delete_impl>(cx, args);
1.255 +}
1.256 +
1.257 +static bool
1.258 +TryPreserveReflector(JSContext *cx, HandleObject obj)
1.259 +{
1.260 + if (obj->getClass()->ext.isWrappedNative ||
1.261 + (obj->getClass()->flags & JSCLASS_IS_DOMJSCLASS) ||
1.262 + (obj->is<ProxyObject>() &&
1.263 + obj->as<ProxyObject>().handler()->family() == GetDOMProxyHandlerFamily()))
1.264 + {
1.265 + JS_ASSERT(cx->runtime()->preserveWrapperCallback);
1.266 + if (!cx->runtime()->preserveWrapperCallback(cx, obj)) {
1.267 + JS_ReportErrorNumber(cx, js_GetErrorMessage, nullptr, JSMSG_BAD_WEAKMAP_KEY);
1.268 + return false;
1.269 + }
1.270 + }
1.271 + return true;
1.272 +}
1.273 +
1.274 +static inline void
1.275 +WeakMapPostWriteBarrier(JSRuntime *rt, ObjectValueMap *weakMap, JSObject *key)
1.276 +{
1.277 +#ifdef JSGC_GENERATIONAL
1.278 + /*
1.279 + * Strip the barriers from the type before inserting into the store buffer.
1.280 + * This will automatically ensure that barriers do not fire during GC.
1.281 + *
1.282 + * Some compilers complain about instantiating the WeakMap class for
1.283 + * unbarriered type arguments, so we cast to a HashMap instead. Because of
1.284 + * WeakMap's multiple inheritace, We need to do this in two stages, first to
1.285 + * the HashMap base class and then to the unbarriered version.
1.286 + */
1.287 + ObjectValueMap::Base *baseHashMap = static_cast<ObjectValueMap::Base *>(weakMap);
1.288 +
1.289 + typedef HashMap<JSObject *, Value> UnbarrieredMap;
1.290 + UnbarrieredMap *unbarrieredMap = reinterpret_cast<UnbarrieredMap *>(baseHashMap);
1.291 +
1.292 + typedef gc::HashKeyRef<UnbarrieredMap, JSObject *> Ref;
1.293 + if (key && IsInsideNursery(rt, key))
1.294 + rt->gcStoreBuffer.putGeneric(Ref((unbarrieredMap), key));
1.295 +#endif
1.296 +}
1.297 +
1.298 +MOZ_ALWAYS_INLINE bool
1.299 +SetWeakMapEntryInternal(JSContext *cx, Handle<WeakMapObject*> mapObj,
1.300 + HandleObject key, HandleValue value)
1.301 +{
1.302 + ObjectValueMap *map = mapObj->getMap();
1.303 + if (!map) {
1.304 + map = cx->new_<ObjectValueMap>(cx, mapObj.get());
1.305 + if (!map)
1.306 + return false;
1.307 + if (!map->init()) {
1.308 + js_delete(map);
1.309 + JS_ReportOutOfMemory(cx);
1.310 + return false;
1.311 + }
1.312 + mapObj->setPrivate(map);
1.313 + }
1.314 +
1.315 + // Preserve wrapped native keys to prevent wrapper optimization.
1.316 + if (!TryPreserveReflector(cx, key))
1.317 + return false;
1.318 +
1.319 + if (JSWeakmapKeyDelegateOp op = key->getClass()->ext.weakmapKeyDelegateOp) {
1.320 + RootedObject delegate(cx, op(key));
1.321 + if (delegate && !TryPreserveReflector(cx, delegate))
1.322 + return false;
1.323 + }
1.324 +
1.325 + JS_ASSERT(key->compartment() == mapObj->compartment());
1.326 + JS_ASSERT_IF(value.isObject(), value.toObject().compartment() == mapObj->compartment());
1.327 + if (!map->put(key, value)) {
1.328 + JS_ReportOutOfMemory(cx);
1.329 + return false;
1.330 + }
1.331 + WeakMapPostWriteBarrier(cx->runtime(), map, key.get());
1.332 + return true;
1.333 +}
1.334 +
1.335 +MOZ_ALWAYS_INLINE bool
1.336 +WeakMap_set_impl(JSContext *cx, CallArgs args)
1.337 +{
1.338 + JS_ASSERT(IsWeakMap(args.thisv()));
1.339 +
1.340 + if (args.length() < 1) {
1.341 + JS_ReportErrorNumber(cx, js_GetErrorMessage, nullptr, JSMSG_MORE_ARGS_NEEDED,
1.342 + "WeakMap.set", "0", "s");
1.343 + return false;
1.344 + }
1.345 + RootedObject key(cx, GetKeyArg(cx, args));
1.346 + if (!key)
1.347 + return false;
1.348 +
1.349 + RootedValue value(cx, (args.length() > 1) ? args[1] : UndefinedValue());
1.350 + Rooted<JSObject*> thisObj(cx, &args.thisv().toObject());
1.351 + Rooted<WeakMapObject*> map(cx, &thisObj->as<WeakMapObject>());
1.352 +
1.353 + args.rval().setUndefined();
1.354 + return SetWeakMapEntryInternal(cx, map, key, value);
1.355 +}
1.356 +
1.357 +static bool
1.358 +WeakMap_set(JSContext *cx, unsigned argc, Value *vp)
1.359 +{
1.360 + CallArgs args = CallArgsFromVp(argc, vp);
1.361 + return CallNonGenericMethod<IsWeakMap, WeakMap_set_impl>(cx, args);
1.362 +}
1.363 +
1.364 +JS_FRIEND_API(bool)
1.365 +JS_NondeterministicGetWeakMapKeys(JSContext *cx, HandleObject objArg, MutableHandleObject ret)
1.366 +{
1.367 + RootedObject obj(cx, objArg);
1.368 + obj = UncheckedUnwrap(obj);
1.369 + if (!obj || !obj->is<WeakMapObject>()) {
1.370 + ret.set(nullptr);
1.371 + return true;
1.372 + }
1.373 + RootedObject arr(cx, NewDenseEmptyArray(cx));
1.374 + if (!arr)
1.375 + return false;
1.376 + ObjectValueMap *map = obj->as<WeakMapObject>().getMap();
1.377 + if (map) {
1.378 + // Prevent GC from mutating the weakmap while iterating.
1.379 + gc::AutoSuppressGC suppress(cx);
1.380 + for (ObjectValueMap::Base::Range r = map->all(); !r.empty(); r.popFront()) {
1.381 + RootedObject key(cx, r.front().key());
1.382 + if (!cx->compartment()->wrap(cx, &key))
1.383 + return false;
1.384 + if (!NewbornArrayPush(cx, arr, ObjectValue(*key)))
1.385 + return false;
1.386 + }
1.387 + }
1.388 + ret.set(arr);
1.389 + return true;
1.390 +}
1.391 +
1.392 +static void
1.393 +WeakMap_mark(JSTracer *trc, JSObject *obj)
1.394 +{
1.395 + if (ObjectValueMap *map = obj->as<WeakMapObject>().getMap())
1.396 + map->trace(trc);
1.397 +}
1.398 +
1.399 +static void
1.400 +WeakMap_finalize(FreeOp *fop, JSObject *obj)
1.401 +{
1.402 + if (ObjectValueMap *map = obj->as<WeakMapObject>().getMap()) {
1.403 + map->check();
1.404 +#ifdef DEBUG
1.405 + map->~ObjectValueMap();
1.406 + memset(static_cast<void *>(map), 0xdc, sizeof(*map));
1.407 + fop->free_(map);
1.408 +#else
1.409 + fop->delete_(map);
1.410 +#endif
1.411 + }
1.412 +}
1.413 +
1.414 +JS_PUBLIC_API(JSObject*)
1.415 +JS::NewWeakMapObject(JSContext *cx)
1.416 +{
1.417 + return NewBuiltinClassInstance(cx, &WeakMapObject::class_);
1.418 +}
1.419 +
1.420 +JS_PUBLIC_API(bool)
1.421 +JS::IsWeakMapObject(JSObject *obj)
1.422 +{
1.423 + return obj->is<WeakMapObject>();
1.424 +}
1.425 +
1.426 +JS_PUBLIC_API(bool)
1.427 +JS::GetWeakMapEntry(JSContext *cx, HandleObject mapObj, HandleObject key,
1.428 + MutableHandleValue rval)
1.429 +{
1.430 + CHECK_REQUEST(cx);
1.431 + assertSameCompartment(cx, key);
1.432 + rval.setUndefined();
1.433 + ObjectValueMap *map = mapObj->as<WeakMapObject>().getMap();
1.434 + if (!map)
1.435 + return true;
1.436 + if (ObjectValueMap::Ptr ptr = map->lookup(key)) {
1.437 + // Read barrier to prevent an incorrectly gray value from escaping the
1.438 + // weak map. See the comment before UnmarkGrayChildren in gc/Marking.cpp
1.439 + ExposeValueToActiveJS(ptr->value().get());
1.440 + rval.set(ptr->value());
1.441 + }
1.442 + return true;
1.443 +}
1.444 +
1.445 +JS_PUBLIC_API(bool)
1.446 +JS::SetWeakMapEntry(JSContext *cx, HandleObject mapObj, HandleObject key,
1.447 + HandleValue val)
1.448 +{
1.449 + CHECK_REQUEST(cx);
1.450 + assertSameCompartment(cx, key, val);
1.451 + Rooted<WeakMapObject*> rootedMap(cx, &mapObj->as<WeakMapObject>());
1.452 + return SetWeakMapEntryInternal(cx, rootedMap, key, val);
1.453 +}
1.454 +
1.455 +static bool
1.456 +WeakMap_construct(JSContext *cx, unsigned argc, Value *vp)
1.457 +{
1.458 + CallArgs args = CallArgsFromVp(argc, vp);
1.459 + JSObject *obj = NewBuiltinClassInstance(cx, &WeakMapObject::class_);
1.460 + if (!obj)
1.461 + return false;
1.462 +
1.463 + args.rval().setObject(*obj);
1.464 + return true;
1.465 +}
1.466 +
1.467 +const Class WeakMapObject::class_ = {
1.468 + "WeakMap",
1.469 + JSCLASS_HAS_PRIVATE | JSCLASS_IMPLEMENTS_BARRIERS |
1.470 + JSCLASS_HAS_CACHED_PROTO(JSProto_WeakMap),
1.471 + JS_PropertyStub, /* addProperty */
1.472 + JS_DeletePropertyStub, /* delProperty */
1.473 + JS_PropertyStub, /* getProperty */
1.474 + JS_StrictPropertyStub, /* setProperty */
1.475 + JS_EnumerateStub,
1.476 + JS_ResolveStub,
1.477 + JS_ConvertStub,
1.478 + WeakMap_finalize,
1.479 + nullptr, /* call */
1.480 + nullptr, /* construct */
1.481 + nullptr, /* xdrObject */
1.482 + WeakMap_mark
1.483 +};
1.484 +
1.485 +static const JSFunctionSpec weak_map_methods[] = {
1.486 + JS_FN("has", WeakMap_has, 1, 0),
1.487 + JS_FN("get", WeakMap_get, 2, 0),
1.488 + JS_FN("delete", WeakMap_delete, 1, 0),
1.489 + JS_FN("set", WeakMap_set, 2, 0),
1.490 + JS_FN("clear", WeakMap_clear, 0, 0),
1.491 + JS_FS_END
1.492 +};
1.493 +
1.494 +JSObject *
1.495 +js_InitWeakMapClass(JSContext *cx, HandleObject obj)
1.496 +{
1.497 + JS_ASSERT(obj->isNative());
1.498 +
1.499 + Rooted<GlobalObject*> global(cx, &obj->as<GlobalObject>());
1.500 +
1.501 + RootedObject weakMapProto(cx, global->createBlankPrototype(cx, &WeakMapObject::class_));
1.502 + if (!weakMapProto)
1.503 + return nullptr;
1.504 +
1.505 + RootedFunction ctor(cx, global->createConstructor(cx, WeakMap_construct,
1.506 + cx->names().WeakMap, 0));
1.507 + if (!ctor)
1.508 + return nullptr;
1.509 +
1.510 + if (!LinkConstructorAndPrototype(cx, ctor, weakMapProto))
1.511 + return nullptr;
1.512 +
1.513 + if (!DefinePropertiesAndBrand(cx, weakMapProto, nullptr, weak_map_methods))
1.514 + return nullptr;
1.515 +
1.516 + if (!GlobalObject::initBuiltinConstructor(cx, global, JSProto_WeakMap, ctor, weakMapProto))
1.517 + return nullptr;
1.518 + return weakMapProto;
1.519 +}
1.520 +
