Example #1
0
PutByIdStatus PutByIdStatus::computeFor(JSGlobalObject* globalObject, const StructureSet& set, StringImpl* uid, bool isDirect)
{
    if (toUInt32FromStringImpl(uid) != PropertyName::NotAnIndex)
        return PutByIdStatus(TakesSlowPath);

    if (set.isEmpty())
        return PutByIdStatus();
    
    PutByIdStatus result;
    result.m_state = Simple;
    for (unsigned i = 0; i < set.size(); ++i) {
        Structure* structure = set[i];
        
        if (structure->typeInfo().overridesGetOwnPropertySlot() && structure->typeInfo().type() != GlobalObjectType)
            return PutByIdStatus(TakesSlowPath);

        if (!structure->propertyAccessesAreCacheable())
            return PutByIdStatus(TakesSlowPath);
    
        unsigned attributes;
        PropertyOffset offset = structure->getConcurrently(uid, attributes);
        if (isValidOffset(offset)) {
            if (attributes & CustomAccessor)
                return PutByIdStatus(MakesCalls);

            if (attributes & (Accessor | ReadOnly))
                return PutByIdStatus(TakesSlowPath);
            
            WatchpointSet* replaceSet = structure->propertyReplacementWatchpointSet(offset);
            if (!replaceSet || replaceSet->isStillValid()) {
                // When this executes, it'll create, and fire, this replacement watchpoint set.
                // That means that  this has probably never executed or that something fishy is
                // going on. Also, we cannot create or fire the watchpoint set from the concurrent
                // JIT thread, so even if we wanted to do this, we'd need to have a lazy thingy.
                // So, better leave this alone and take slow path.
                return PutByIdStatus(TakesSlowPath);
            }
            
            if (!result.appendVariant(PutByIdVariant::replace(structure, offset)))
                return PutByIdStatus(TakesSlowPath);
            continue;
        }
    
        // Our hypothesis is that we're doing a transition. Before we prove that this is really
        // true, we want to do some sanity checks.
    
        // Don't cache put transitions on dictionaries.
        if (structure->isDictionary())
            return PutByIdStatus(TakesSlowPath);

        // If the structure corresponds to something that isn't an object, then give up, since
        // we don't want to be adding properties to strings.
        if (structure->typeInfo().type() == StringType)
            return PutByIdStatus(TakesSlowPath);
    
        RefPtr<IntendedStructureChain> chain;
        if (!isDirect) {
            chain = adoptRef(new IntendedStructureChain(globalObject, structure));
        
            // If the prototype chain has setters or read-only properties, then give up.
            if (chain->mayInterceptStoreTo(uid))
                return PutByIdStatus(TakesSlowPath);
        
            // If the prototype chain hasn't been normalized (i.e. there are proxies or dictionaries)
            // then give up. The dictionary case would only happen if this structure has not been
            // used in an optimized put_by_id transition. And really the only reason why we would
            // bail here is that I don't really feel like having the optimizing JIT go and flatten
            // dictionaries if we have evidence to suggest that those objects were never used as
            // prototypes in a cacheable prototype access - i.e. there's a good chance that some of
            // the other checks below will fail.
            if (structure->isProxy() || !chain->isNormalized())
                return PutByIdStatus(TakesSlowPath);
        }
    
        // We only optimize if there is already a structure that the transition is cached to.
        Structure* transition = Structure::addPropertyTransitionToExistingStructureConcurrently(structure, uid, 0, offset);
        if (!transition)
            return PutByIdStatus(TakesSlowPath);
        ASSERT(isValidOffset(offset));
    
        bool didAppend = result.appendVariant(
            PutByIdVariant::transition(structure, transition, chain.get(), offset));
        if (!didAppend)
            return PutByIdStatus(TakesSlowPath);
    }
    
    return result;
}
PutByIdStatus PutByIdStatus::computeFor(JSGlobalObject* globalObject, const StructureSet& set, UniquedStringImpl* uid, bool isDirect)
{
    if (parseIndex(*uid))
        return PutByIdStatus(TakesSlowPath);

    if (set.isEmpty())
        return PutByIdStatus();
    
    PutByIdStatus result;
    result.m_state = Simple;
    for (unsigned i = 0; i < set.size(); ++i) {
        Structure* structure = set[i];
        
        if (structure->typeInfo().overridesGetOwnPropertySlot() && structure->typeInfo().type() != GlobalObjectType)
            return PutByIdStatus(TakesSlowPath);

        if (!structure->propertyAccessesAreCacheable())
            return PutByIdStatus(TakesSlowPath);
    
        unsigned attributes;
        PropertyOffset offset = structure->getConcurrently(uid, attributes);
        if (isValidOffset(offset)) {
            if (attributes & CustomAccessor)
                return PutByIdStatus(MakesCalls);

            if (attributes & (Accessor | ReadOnly))
                return PutByIdStatus(TakesSlowPath);
            
            WatchpointSet* replaceSet = structure->propertyReplacementWatchpointSet(offset);
            if (!replaceSet || replaceSet->isStillValid()) {
                // When this executes, it'll create, and fire, this replacement watchpoint set.
                // That means that  this has probably never executed or that something fishy is
                // going on. Also, we cannot create or fire the watchpoint set from the concurrent
                // JIT thread, so even if we wanted to do this, we'd need to have a lazy thingy.
                // So, better leave this alone and take slow path.
                return PutByIdStatus(TakesSlowPath);
            }

            PutByIdVariant variant =
                PutByIdVariant::replace(structure, offset, structure->inferredTypeDescriptorFor(uid));
            if (!result.appendVariant(variant))
                return PutByIdStatus(TakesSlowPath);
            continue;
        }
    
        // Our hypothesis is that we're doing a transition. Before we prove that this is really
        // true, we want to do some sanity checks.
    
        // Don't cache put transitions on dictionaries.
        if (structure->isDictionary())
            return PutByIdStatus(TakesSlowPath);

        // If the structure corresponds to something that isn't an object, then give up, since
        // we don't want to be adding properties to strings.
        if (!structure->typeInfo().isObject())
            return PutByIdStatus(TakesSlowPath);
    
        ObjectPropertyConditionSet conditionSet;
        if (!isDirect) {
            conditionSet = generateConditionsForPropertySetterMissConcurrently(
                globalObject->vm(), globalObject, structure, uid);
            if (!conditionSet.isValid())
                return PutByIdStatus(TakesSlowPath);
        }
    
        // We only optimize if there is already a structure that the transition is cached to.
        Structure* transition =
            Structure::addPropertyTransitionToExistingStructureConcurrently(structure, uid, 0, offset);
        if (!transition)
            return PutByIdStatus(TakesSlowPath);
        ASSERT(isValidOffset(offset));
    
        bool didAppend = result.appendVariant(
            PutByIdVariant::transition(
                structure, transition, conditionSet, offset,
                transition->inferredTypeDescriptorFor(uid)));
        if (!didAppend)
            return PutByIdStatus(TakesSlowPath);
    }
    
    return result;
}
Example #3
0
PutByIdStatus PutByIdStatus::computeForStubInfo(
    const ConcurrentJITLocker& locker, CodeBlock* profiledBlock, StructureStubInfo* stubInfo,
    StringImpl* uid, CallLinkStatus::ExitSiteData callExitSiteData)
{
    if (!stubInfo || !stubInfo->seen)
        return PutByIdStatus();
    
    switch (stubInfo->accessType) {
    case access_unset:
        // If the JIT saw it but didn't optimize it, then assume that this takes slow path.
        return PutByIdStatus(TakesSlowPath);
        
    case access_put_by_id_replace: {
        PropertyOffset offset =
            stubInfo->u.putByIdReplace.baseObjectStructure->getConcurrently(uid);
        if (isValidOffset(offset)) {
            return PutByIdVariant::replace(
                stubInfo->u.putByIdReplace.baseObjectStructure.get(), offset);
        }
        return PutByIdStatus(TakesSlowPath);
    }
        
    case access_put_by_id_transition_normal:
    case access_put_by_id_transition_direct: {
        ASSERT(stubInfo->u.putByIdTransition.previousStructure->transitionWatchpointSetHasBeenInvalidated());
        PropertyOffset offset = 
            stubInfo->u.putByIdTransition.structure->getConcurrently(uid);
        if (isValidOffset(offset)) {
            RefPtr<IntendedStructureChain> chain;
            if (stubInfo->u.putByIdTransition.chain) {
                chain = adoptRef(new IntendedStructureChain(
                    profiledBlock, stubInfo->u.putByIdTransition.previousStructure.get(),
                    stubInfo->u.putByIdTransition.chain.get()));
            }
            return PutByIdVariant::transition(
                stubInfo->u.putByIdTransition.previousStructure.get(),
                stubInfo->u.putByIdTransition.structure.get(),
                chain.get(), offset);
        }
        return PutByIdStatus(TakesSlowPath);
    }
        
    case access_put_by_id_list: {
        PolymorphicPutByIdList* list = stubInfo->u.putByIdList.list;
        
        PutByIdStatus result;
        result.m_state = Simple;
        
        State slowPathState = TakesSlowPath;
        for (unsigned i = 0; i < list->size(); ++i) {
            const PutByIdAccess& access = list->at(i);
            
            switch (access.type()) {
            case PutByIdAccess::Setter:
            case PutByIdAccess::CustomSetter:
                slowPathState = MakesCalls;
                break;
            default:
                break;
            }
        }
        
        for (unsigned i = 0; i < list->size(); ++i) {
            const PutByIdAccess& access = list->at(i);
            
            PutByIdVariant variant;
            
            switch (access.type()) {
            case PutByIdAccess::Replace: {
                Structure* structure = access.structure();
                PropertyOffset offset = structure->getConcurrently(uid);
                if (!isValidOffset(offset))
                    return PutByIdStatus(slowPathState);
                variant = PutByIdVariant::replace(structure, offset);
                break;
            }
                
            case PutByIdAccess::Transition: {
                PropertyOffset offset =
                    access.newStructure()->getConcurrently(uid);
                if (!isValidOffset(offset))
                    return PutByIdStatus(slowPathState);
                RefPtr<IntendedStructureChain> chain;
                if (access.chain()) {
                    chain = adoptRef(new IntendedStructureChain(
                        profiledBlock, access.oldStructure(), access.chain()));
                    if (!chain->isStillValid())
                        continue;
                }
                variant = PutByIdVariant::transition(
                    access.oldStructure(), access.newStructure(), chain.get(), offset);
                break;
            }
                
            case PutByIdAccess::Setter: {
                Structure* structure = access.structure();
                
                ComplexGetStatus complexGetStatus = ComplexGetStatus::computeFor(
                    profiledBlock, structure, access.chain(), access.chainCount(), uid);
                
                switch (complexGetStatus.kind()) {
                case ComplexGetStatus::ShouldSkip:
                    continue;
                    
                case ComplexGetStatus::TakesSlowPath:
                    return PutByIdStatus(slowPathState);
                    
                case ComplexGetStatus::Inlineable: {
                    AccessorCallJITStubRoutine* stub = static_cast<AccessorCallJITStubRoutine*>(
                        access.stubRoutine());
                    std::unique_ptr<CallLinkStatus> callLinkStatus =
                        std::make_unique<CallLinkStatus>(
                            CallLinkStatus::computeFor(
                                locker, profiledBlock, *stub->m_callLinkInfo, callExitSiteData));
                    
                    variant = PutByIdVariant::setter(
                        structure, complexGetStatus.offset(), complexGetStatus.chain(),
                        std::move(callLinkStatus));
                } }
                break;
            }
                
            case PutByIdAccess::CustomSetter:
                return PutByIdStatus(MakesCalls);

            default:
                return PutByIdStatus(slowPathState);
            }
            
            if (!result.appendVariant(variant))
                return PutByIdStatus(slowPathState);
        }
        
        return result;
    }
        
    default:
        return PutByIdStatus(TakesSlowPath);
    }
}
PutByIdStatus PutByIdStatus::computeForStubInfo(
    const ConcurrentJITLocker& locker, CodeBlock* profiledBlock, StructureStubInfo* stubInfo,
    UniquedStringImpl* uid, CallLinkStatus::ExitSiteData callExitSiteData)
{
    if (!stubInfo || !stubInfo->everConsidered)
        return PutByIdStatus();
    
    if (stubInfo->tookSlowPath)
        return PutByIdStatus(TakesSlowPath);
    
    switch (stubInfo->cacheType) {
    case CacheType::Unset:
        // This means that we attempted to cache but failed for some reason.
        return PutByIdStatus(TakesSlowPath);
        
    case CacheType::PutByIdReplace: {
        PropertyOffset offset =
            stubInfo->u.byIdSelf.baseObjectStructure->getConcurrently(uid);
        if (isValidOffset(offset)) {
            return PutByIdVariant::replace(
                stubInfo->u.byIdSelf.baseObjectStructure.get(), offset, InferredType::Top);
        }
        return PutByIdStatus(TakesSlowPath);
    }
        
    case CacheType::Stub: {
        PolymorphicAccess* list = stubInfo->u.stub;
        
        PutByIdStatus result;
        result.m_state = Simple;
        
        State slowPathState = TakesSlowPath;
        for (unsigned i = 0; i < list->size(); ++i) {
            const AccessCase& access = list->at(i);
            if (access.doesCalls())
                slowPathState = MakesCalls;
        }
        
        for (unsigned i = 0; i < list->size(); ++i) {
            const AccessCase& access = list->at(i);
            if (access.viaProxy())
                return PutByIdStatus(slowPathState);
            
            PutByIdVariant variant;
            
            switch (access.type()) {
            case AccessCase::Replace: {
                Structure* structure = access.structure();
                PropertyOffset offset = structure->getConcurrently(uid);
                if (!isValidOffset(offset))
                    return PutByIdStatus(slowPathState);
                variant = PutByIdVariant::replace(
                    structure, offset, structure->inferredTypeDescriptorFor(uid));
                break;
            }
                
            case AccessCase::Transition: {
                PropertyOffset offset =
                    access.newStructure()->getConcurrently(uid);
                if (!isValidOffset(offset))
                    return PutByIdStatus(slowPathState);
                ObjectPropertyConditionSet conditionSet = access.conditionSet();
                if (!conditionSet.structuresEnsureValidity())
                    return PutByIdStatus(slowPathState);
                variant = PutByIdVariant::transition(
                    access.structure(), access.newStructure(), conditionSet, offset,
                    access.newStructure()->inferredTypeDescriptorFor(uid));
                break;
            }
                
            case AccessCase::Setter: {
                Structure* structure = access.structure();
                
                ComplexGetStatus complexGetStatus = ComplexGetStatus::computeFor(
                    structure, access.conditionSet(), uid);
                
                switch (complexGetStatus.kind()) {
                case ComplexGetStatus::ShouldSkip:
                    continue;
                    
                case ComplexGetStatus::TakesSlowPath:
                    return PutByIdStatus(slowPathState);
                    
                case ComplexGetStatus::Inlineable: {
                    CallLinkInfo* callLinkInfo = access.callLinkInfo();
                    ASSERT(callLinkInfo);
                    std::unique_ptr<CallLinkStatus> callLinkStatus =
                        std::make_unique<CallLinkStatus>(
                            CallLinkStatus::computeFor(
                                locker, profiledBlock, *callLinkInfo, callExitSiteData));
                    
                    variant = PutByIdVariant::setter(
                        structure, complexGetStatus.offset(), complexGetStatus.conditionSet(),
                        WTFMove(callLinkStatus));
                } }
                break;
            }
                
            case AccessCase::CustomSetter:
                return PutByIdStatus(MakesCalls);

            default:
                return PutByIdStatus(slowPathState);
            }
            
            if (!result.appendVariant(variant))
                return PutByIdStatus(slowPathState);
        }
        
        return result;
    }
        
    default:
        return PutByIdStatus(TakesSlowPath);
    }
}