Beispiel #1
0
static LookupStatus
UpdateSetGlobalName(VMFrame &f, ic::SetGlobalNameIC *ic, JSObject *obj, UnrootedShape shape)
{
    /* Give globals a chance to appear. */
    if (!shape)
        return Lookup_Uncacheable;

    if (!shape->hasDefaultSetter() ||
        !shape->writable() ||
        !shape->hasSlot() ||
        obj->watched())
    {
        /* Disable the IC for weird shape attributes and watchpoints. */
        PatchSetFallback(f, ic);
        return Lookup_Uncacheable;
    }

    /* Object is not branded, so we can use the inline path. */
    Repatcher repatcher(f.chunk());
    ic->patchInlineShapeGuard(repatcher, obj->lastProperty());

    uint32_t index = obj->dynamicSlotIndex(shape->slot());
    JSC::CodeLocationLabel label = ic->fastPathStart.labelAtOffset(ic->loadStoreOffset);
    repatcher.patchAddressOffsetForValueStore(label, index * sizeof(Value),
                                              ic->vr.isTypeKnown());

    return Lookup_Cacheable;
}
void
Shape::removeChild(UnrootedShape child)
{
    JS_ASSERT(!child->inDictionary());
    JS_ASSERT(child->parent == this);

    KidsPointer *kidp = &kids;

    if (kidp->isShape()) {
        JS_ASSERT(kidp->toShape() == child);
        kidp->setNull();
        child->parent = NULL;
        return;
    }

    KidsHash *hash = kidp->toHash();
    JS_ASSERT(hash->count() >= 2);      /* otherwise kidp->isShape() should be true */

    hash->remove(child);
    child->parent = NULL;

    if (hash->count() == 1) {
        /* Convert from HASH form back to SHAPE form. */
        KidsHash::Range r = hash->all();
        Shape *otherChild = r.front();
        JS_ASSERT((r.popFront(), r.empty()));    /* No more elements! */
        kidp->setShape(otherChild);
        js_delete(hash);
    }
}
bool
PropertyTree::insertChild(JSContext *cx, UnrootedShape parent, UnrootedShape child)
{
    JS_ASSERT(!parent->inDictionary());
    JS_ASSERT(!child->parent);
    JS_ASSERT(!child->inDictionary());
    JS_ASSERT(cx->compartment == compartment);
    JS_ASSERT(child->compartment() == parent->compartment());

    KidsPointer *kidp = &parent->kids;

    if (kidp->isNull()) {
        child->setParent(parent);
        kidp->setShape(child);
        return true;
    }

    if (kidp->isShape()) {
        UnrootedShape shape = kidp->toShape();
        JS_ASSERT(shape != child);
        JS_ASSERT(!shape->matches(child));

        KidsHash *hash = HashChildren(shape, child);
        if (!hash) {
            JS_ReportOutOfMemory(cx);
            return false;
        }
        kidp->setHash(hash);
        child->setParent(parent);
        return true;
    }

    if (!kidp->toHash()->putNew(child, child)) {
        JS_ReportOutOfMemory(cx);
        return false;
    }

    child->setParent(parent);
    return true;
}
UnrootedShape
PropertyTree::getChild(JSContext *cx, Shape *parent_, uint32_t nfixed, const StackShape &child)
{
    AssertCanGC();

    {
        UnrootedShape shape = NULL;

        JS_ASSERT(parent_);

        /*
         * The property tree has extremely low fan-out below its root in
         * popular embeddings with real-world workloads. Patterns such as
         * defining closures that capture a constructor's environment as
         * getters or setters on the new object that is passed in as
         * |this| can significantly increase fan-out below the property
         * tree root -- see bug 335700 for details.
         */
        KidsPointer *kidp = &parent_->kids;
        if (kidp->isShape()) {
            UnrootedShape kid = kidp->toShape();
            if (kid->matches(child))
                shape = kid;
        } else if (kidp->isHash()) {
            if (KidsHash::Ptr p = kidp->toHash()->lookup(child))
                shape = *p;
        } else {
            /* If kidp->isNull(), we always insert. */
        }

#ifdef JSGC_INCREMENTAL
        if (shape) {
            JS::Zone *zone = shape->zone();
            if (zone->needsBarrier()) {
                /*
                 * We need a read barrier for the shape tree, since these are weak
                 * pointers.
                 */
                Shape *tmp = shape;
                MarkShapeUnbarriered(zone->barrierTracer(), &tmp, "read barrier");
                JS_ASSERT(tmp == shape);
            } else if (zone->isGCSweeping() && !shape->isMarked() &&
                       !shape->arenaHeader()->allocatedDuringIncremental)
            {
                /*
                 * The shape we've found is unreachable and due to be finalized, so
                 * remove our weak reference to it and don't use it.
                 */
                JS_ASSERT(parent_->isMarked());
                parent_->removeChild(shape);
                shape = NULL;
            }
        }
#endif

        if (shape)
            return shape;
    }

    StackShape::AutoRooter childRoot(cx, &child);
    RootedShape parent(cx, parent_);

    UnrootedShape shape = newShape(cx);
    if (!shape)
        return UnrootedShape(NULL);

    new (shape) Shape(child, nfixed);

    if (!insertChild(cx, parent, shape))
        return UnrootedShape(NULL);

    return shape;
}
static void
StatsCellCallback(JSRuntime *rt, void *data, void *thing, JSGCTraceKind traceKind,
                  size_t thingSize)
{
    IteratorClosure *closure = static_cast<IteratorClosure *>(data);
    RuntimeStats *rtStats = closure->rtStats;
    CompartmentStats *cStats = rtStats->currCompartmentStats;
    switch (traceKind) {
    case JSTRACE_OBJECT:
    {
        JSObject *obj = static_cast<JSObject *>(thing);
        if (obj->isFunction()) {
            cStats->gcHeapObjectsFunction += thingSize;
        } else if (obj->isArray()) {
            cStats->gcHeapObjectsDenseArray += thingSize;
        } else if (obj->isCrossCompartmentWrapper()) {
            cStats->gcHeapObjectsCrossCompartmentWrapper += thingSize;
        } else {
            cStats->gcHeapObjectsOrdinary += thingSize;
        }

        ObjectsExtraSizes objectsExtra;
        obj->sizeOfExcludingThis(rtStats->mallocSizeOf, &objectsExtra);
        cStats->objectsExtra.add(objectsExtra);

        // JSObject::sizeOfExcludingThis() doesn't measure objectsExtraPrivate,
        // so we do it here.
        if (ObjectPrivateVisitor *opv = closure->opv) {
            nsISupports *iface;
            if (opv->getISupports(obj, &iface) && iface) {
                cStats->objectsExtra.private_ += opv->sizeOfIncludingThis(iface);
            }
        }
        break;
    }
    case JSTRACE_STRING:
    {
        JSString *str = static_cast<JSString *>(thing);

        size_t strSize = str->sizeOfExcludingThis(rtStats->mallocSizeOf);

        // If we can't grow hugeStrings, let's just call this string non-huge.
        // We're probably about to OOM anyway.
        if (strSize >= HugeStringInfo::MinSize() && cStats->hugeStrings.growBy(1)) {
            cStats->gcHeapStringsNormal += thingSize;
            HugeStringInfo &info = cStats->hugeStrings.back();
            info.length = str->length();
            info.size = strSize;
            PutEscapedString(info.buffer, sizeof(info.buffer), &str->asLinear(), 0);
        } else if (str->isShort()) {
            MOZ_ASSERT(strSize == 0);
            cStats->gcHeapStringsShort += thingSize;
        } else {
            cStats->gcHeapStringsNormal += thingSize;
            cStats->stringCharsNonHuge += strSize;
        }
        break;
    }
    case JSTRACE_SHAPE:
    {
        UnrootedShape shape = static_cast<RawShape>(thing);
        size_t propTableSize, kidsSize;
        shape->sizeOfExcludingThis(rtStats->mallocSizeOf, &propTableSize, &kidsSize);
        if (shape->inDictionary()) {
            cStats->gcHeapShapesDict += thingSize;
            cStats->shapesExtraDictTables += propTableSize;
            JS_ASSERT(kidsSize == 0);
        } else {
            if (shape->base()->getObjectParent() == shape->compartment()->maybeGlobal()) {
                cStats->gcHeapShapesTreeGlobalParented += thingSize;
            } else {
                cStats->gcHeapShapesTreeNonGlobalParented += thingSize;
            }
            cStats->shapesExtraTreeTables += propTableSize;
            cStats->shapesExtraTreeShapeKids += kidsSize;
        }
        break;
    }
    case JSTRACE_BASE_SHAPE:
    {
        cStats->gcHeapShapesBase += thingSize;
        break;
    }
    case JSTRACE_SCRIPT:
    {
        JSScript *script = static_cast<JSScript *>(thing);
        cStats->gcHeapScripts += thingSize;
        cStats->scriptData += script->sizeOfData(rtStats->mallocSizeOf);
#ifdef JS_METHODJIT
        cStats->jaegerData += script->sizeOfJitScripts(rtStats->mallocSizeOf);
# ifdef JS_ION
        cStats->ionData += ion::MemoryUsed(script, rtStats->mallocSizeOf);
# endif
#endif

        ScriptSource *ss = script->scriptSource();
        SourceSet::AddPtr entry = closure->seenSources.lookupForAdd(ss);
        if (!entry) {
            closure->seenSources.add(entry, ss); // Not much to be done on failure.
            rtStats->runtime.scriptSources += ss->sizeOfIncludingThis(rtStats->mallocSizeOf);
        }
        break;
    }
    case JSTRACE_IONCODE:
    {
#ifdef JS_METHODJIT
# ifdef JS_ION
        cStats->gcHeapIonCodes += thingSize;
        // The code for a script is counted in ExecutableAllocator::sizeOfCode().
# endif
#endif
        break;
    }
    case JSTRACE_TYPE_OBJECT:
    {
        types::TypeObject *obj = static_cast<types::TypeObject *>(thing);
        cStats->gcHeapTypeObjects += thingSize;
        cStats->typeInference.typeObjects += obj->sizeOfExcludingThis(rtStats->mallocSizeOf);
        break;
    }
    }
    // Yes, this is a subtraction:  see StatsArenaCallback() for details.
    cStats->gcHeapUnusedGcThings -= thingSize;
}
bool
js::GetOwnProperty(JSContext *cx, Handle<ObjectImpl*> obj, PropertyId pid_, unsigned resolveFlags,
                   PropDesc *desc)
{
    NEW_OBJECT_REPRESENTATION_ONLY();

    JS_CHECK_RECURSION(cx, return false);

    Rooted<PropertyId> pid(cx, pid_);

    if (static_cast<JSObject *>(obj.get())->isProxy()) {
        MOZ_NOT_REACHED("NYI: proxy [[GetOwnProperty]]");
        return false;
    }

    /* |shape| is always set /after/ a GC. */
    UnrootedShape shape = obj->nativeLookup(cx, pid);
    if (!shape) {
        DropUnrooted(shape);

        /* Not found: attempt to resolve it. */
        Class *clasp = obj->getClass();
        JSResolveOp resolve = clasp->resolve;
        if (resolve != JS_ResolveStub) {
            Rooted<jsid> id(cx, pid.get().asId());
            Rooted<JSObject*> robj(cx, static_cast<JSObject*>(obj.get()));
            if (clasp->flags & JSCLASS_NEW_RESOLVE) {
                Rooted<JSObject*> obj2(cx, NULL);
                JSNewResolveOp op = reinterpret_cast<JSNewResolveOp>(resolve);
                if (!op(cx, robj, id, resolveFlags, &obj2))
                    return false;
            } else {
                if (!resolve(cx, robj, id))
                    return false;
            }
        }

        /* Now look it up again. */
        shape = obj->nativeLookup(cx, pid);
        if (!shape) {
            desc->setUndefined();
            return true;
        }
    }

    if (shape->isDataDescriptor()) {
        *desc = PropDesc(obj->nativeGetSlot(shape->slot()), shape->writability(),
                         shape->enumerability(), shape->configurability());
        return true;
    }

    if (shape->isAccessorDescriptor()) {
        *desc = PropDesc(shape->getterValue(), shape->setterValue(),
                         shape->enumerability(), shape->configurability());
        return true;
    }

    MOZ_NOT_REACHED("NYI: PropertyOp-based properties");
    return false;
}
void
js::ObjectImpl::checkShapeConsistency()
{
    static int throttle = -1;
    if (throttle < 0) {
        if (const char *var = getenv("JS_CHECK_SHAPE_THROTTLE"))
            throttle = atoi(var);
        if (throttle < 0)
            throttle = 0;
    }
    if (throttle == 0)
        return;

    MOZ_ASSERT(isNative());

    UnrootedShape shape = lastProperty();
    UnrootedShape prev = NULL;

    if (inDictionaryMode()) {
        MOZ_ASSERT(shape->hasTable());

        ShapeTable &table = shape->table();
        for (uint32_t fslot = table.freelist; fslot != SHAPE_INVALID_SLOT;
             fslot = getSlot(fslot).toPrivateUint32()) {
            MOZ_ASSERT(fslot < slotSpan());
        }

        for (int n = throttle; --n >= 0 && shape->parent; shape = shape->parent) {
            MOZ_ASSERT_IF(lastProperty() != shape, !shape->hasTable());

            Shape **spp = table.search(shape->propid(), false);
            MOZ_ASSERT(SHAPE_FETCH(spp) == shape);
        }

        shape = lastProperty();
        for (int n = throttle; --n >= 0 && shape; shape = shape->parent) {
            MOZ_ASSERT_IF(shape->slot() != SHAPE_INVALID_SLOT, shape->slot() < slotSpan());
            if (!prev) {
                MOZ_ASSERT(lastProperty() == shape);
                MOZ_ASSERT(shape->listp == &shape_);
            } else {
                MOZ_ASSERT(shape->listp == &prev->parent);
            }
            prev = shape;
        }
    } else {
        for (int n = throttle; --n >= 0 && shape->parent; shape = shape->parent) {
            if (shape->hasTable()) {
                ShapeTable &table = shape->table();
                MOZ_ASSERT(shape->parent);
                for (Shape::Range r(shape); !r.empty(); r.popFront()) {
                    Shape **spp = table.search(r.front().propid(), false);
                    MOZ_ASSERT(SHAPE_FETCH(spp) == &r.front());
                }
            }
            if (prev) {
                MOZ_ASSERT(prev->maybeSlot() >= shape->maybeSlot());
                shape->kids.checkConsistency(prev);
            }
            prev = shape;
        }
    }
}