ChakraCore/lib/Runtime/Base/ScriptContext.h

//-------------------------------------------------------------------------------------------------------
// Copyright (C) Microsoft. All rights reserved.
// Licensed under the MIT license. See LICENSE.txt file in the project root for full license information.
//-------------------------------------------------------------------------------------------------------
#pragma once

#ifdef ENABLE_SCRIPT_PROFILING
#include "activprof.h"
#endif

#if DBG || ENABLE_REGEX_CONFIG_OPTIONS || defined(PROFILE_STRINGS)
#define NEED_MISC_ALLOCATOR
#endif

#define BuiltInFunctionsScriptId 0

using namespace PlatformAgnostic;

class NativeCodeGenerator;
class BackgroundParser;
struct IActiveScriptDirect;
#ifdef ENABLE_BASIC_TELEMETRY
class ScriptContextTelemetry;
#endif
namespace Js
{
    class ScriptContext;
    class ScriptEditQuery;
    class MutationBreakpoint;
    class StringProfiler;
    class DebugContext;
    struct HaltCallback;
    struct DebuggerOptionsCallback;
    class ModuleRecordBase;
}

// Created for every source buffer passed by host.
// This structure has all the details.
class SRCINFO
{
    // We currently don't free SRCINFO object so we don't want to add extra variables here.
    // In future, when we do make it freeable and will be able to allocate more than one per Module,
    // we can move variables m_isGlobalFunc and m_isEval from FunctionBody.cpp here.
public:
    SourceContextInfo * sourceContextInfo;
    ULONG dlnHost;             // Line number passed to ParseScriptText
    ULONG ulColumnHost;        // Column number on the line where the parse script text started
    ULONG lnMinHost;           // Line offset of first host-supplied line
    ULONG ichMinHost;          // Range of host supplied characters
    ULONG ichLimHost;
    ULONG ulCharOffset;        // Char offset of the source text relative to the document. (Populated using IActiveScriptContext)
    Js::ModuleID moduleID;
    ULONG grfsi;

    static SRCINFO* Copy(Recycler* recycler, const SRCINFO* srcInfo)
    {
        SRCINFO* copySrcInfo = RecyclerNew(recycler, SRCINFO, *srcInfo);
        return copySrcInfo;
    }
};

struct CustomExternalObjectOperations
{
    size_t offsetOfOperationsUsage;
    DWORD operationFlagEquals;
    DWORD operationFlagStrictEquals;
};

enum ExternalJitData
{
    ExternalJitData_CustomExternalObjectOperations
};

enum LoadScriptFlag
{
    LoadScriptFlag_None         = 0x0,
    LoadScriptFlag_Expression   = 0x1,                  // the script returns a value.
    LoadScriptFlag_disableDeferredParse = 0x2,          // do not defer-parse the code.
    LoadScriptFlag_isByteCodeBufferForLibrary = 0x4,    // for bytecode buffer
    LoadScriptFlag_disableAsmJs = 0x8,                  // disable parse as asmjs. The code is not conform to asmjs requirement.
    LoadScriptFlag_Module = 0x10,                       // input script is module code.
    LoadScriptFlag_isFunction = 0x20,                   // input script is in a function scope, not global code.
    LoadScriptFlag_Utf8Source = 0x40,                   // input buffer is utf8 encoded.
    LoadScriptFlag_LibraryCode = 0x80                   // for debugger, indicating 'not my code'
};

class HostScriptContext
{
public:
    HostScriptContext(Js::ScriptContext* inScriptContext) { this->scriptContext = inScriptContext; }
    virtual void Delete() = 0;
    virtual HRESULT GetPreviousHostScriptContext(__deref_out HostScriptContext** ppUnkCaller) = 0;
    virtual HRESULT PushHostScriptContext() = 0;
    virtual void PopHostScriptContext() = 0;

    virtual HRESULT SetCaller(IUnknown *punkNew, IUnknown **ppunkPrev) = 0;
    virtual HRESULT GetDispatchExCaller(__deref_out void** dispatchExCaller) = 0;
    virtual void ReleaseDispatchExCaller(__in void* dispatchExCaler) = 0;
    virtual Js::ModuleRoot * GetModuleRoot(int moduleID) = 0;
    virtual HRESULT CheckCrossDomainScriptContext(__in Js::ScriptContext* scriptContext) = 0;

    virtual HRESULT GetHostContextUrl(__in DWORD_PTR hostSourceContext, __out BSTR& pUrl) = 0;
    virtual BOOL HasCaller() = 0;
    virtual void CleanDynamicCodeCache() = 0;
    virtual HRESULT VerifyDOMSecurity(Js::ScriptContext* targetContext, Js::Var obj) = 0;

    virtual HRESULT CheckEvalRestriction() = 0;
    virtual HRESULT HostExceptionFromHRESULT(HRESULT hr, Js::Var* outError) = 0;

    virtual HRESULT GetExternalJitData(ExternalJitData id, void *data) = 0;
    virtual HRESULT SetDispatchInvoke(Js::JavascriptMethod dispatchInvoke) = 0;
    virtual HRESULT ArrayBufferFromExternalObject(__in Js::RecyclableObject *obj,
        __out Js::ArrayBuffer **ppArrayBuffer) = 0;
    virtual Js::JavascriptError* CreateWinRTError(IErrorInfo* perrinfo, Js::RestrictedErrorStrings * proerrstr) = 0;
    virtual HRESULT EnqueuePromiseTask(Js::Var varTask) = 0;

    virtual HRESULT FetchImportedModule(Js::ModuleRecordBase* referencingModule, LPCOLESTR specifier, Js::ModuleRecordBase** dependentModuleRecord) = 0;
    virtual HRESULT NotifyHostAboutModuleReady(Js::ModuleRecordBase* referencingModule, Js::Var exceptionVar) = 0;

    Js::ScriptContext* GetScriptContext() { return scriptContext; }

    virtual bool SetCrossSiteForFunctionType(Js::JavascriptFunction * function) = 0;
#if DBG_DUMP || defined(PROFILE_EXEC) || defined(PROFILE_MEM)
    virtual void EnsureParentInfo(Js::ScriptContext* scriptContext = NULL) = 0;
#endif
#if DBG
    virtual bool IsHostCrossSiteThunk(Js::JavascriptMethod address) = 0;
#endif
private:
    Js::ScriptContext* scriptContext;
};

#if ENABLE_TTD
//A class that we use to pass in a functor from the host when we need to inform it about something we are doing
class HostScriptContextCallbackFunctor
{
public:
    void* HostData;
    void(*pfOnScriptLoadCallback)(void* hostData, Js::JavascriptFunction* scriptFunction, Js::Utf8SourceInfo* utf8SourceInfo, CompileScriptException* compileException);

    HostScriptContextCallbackFunctor()
        : HostData(nullptr), pfOnScriptLoadCallback(nullptr)
    {
        ;
    }

    HostScriptContextCallbackFunctor(void* callbackData, void(*pfcallbackOnScriptLoad)(void* hostData, Js::JavascriptFunction* scriptFunction, Js::Utf8SourceInfo* utf8SourceInfo, CompileScriptException* compileException))
        : HostData(callbackData), pfOnScriptLoadCallback(pfcallbackOnScriptLoad)
    {
        ;
    }
};
#endif

namespace Js
{

#pragma pack(push, 1)
    struct StackFrameInfo
    {
        StackFrameInfo() { }
        StackFrameInfo(DWORD_PTR _scriptContextID
            , UINT32 _sourceLocationLineNumber
            , UINT32 _sourceLocationColumnNumber
            , UINT32 _methodIDOrNameIndex
            , UINT8 _isFrameIndex)
            : scriptContextID(_scriptContextID)
            , sourceLocationLineNumber(_sourceLocationLineNumber)
            , sourceLocationColumnNumber(_sourceLocationColumnNumber)
            , methodIDOrNameIndex(_methodIDOrNameIndex)
            , isFrameIndex(_isFrameIndex)
        { }

        DWORD_PTR scriptContextID;
        UINT32 sourceLocationLineNumber;
        UINT32 sourceLocationColumnNumber;
        UINT32 methodIDOrNameIndex;
        UINT8  isFrameIndex;
    };
#pragma pack(pop)

#ifdef ENABLE_PROJECTION
    class ProjectionConfiguration
    {
    public:
        ProjectionConfiguration() : targetVersion(0)
        {
        }

        DWORD GetTargetVersion() const { return this->targetVersion; }
        void SetTargetVersion(DWORD version) { this->targetVersion = version; }

        bool IsTargetWindows8() const           { return this->targetVersion == NTDDI_WIN8; }
        bool IsTargetWindowsBlueOrLater() const { return this->targetVersion >= NTDDI_WINBLUE; }

    private:
        DWORD targetVersion;
    };
#endif // ENABLE_PROJECTION

    class ScriptConfiguration
    {
    public:
        ScriptConfiguration(const ThreadConfiguration * const threadConfig, const bool isOptimizedForManyInstances) :
#ifdef ENABLE_PROJECTION
            HostType(Configuration::Global.flags.HostType),
            WinRTConstructorAllowed(Configuration::Global.flags.WinRTConstructorAllowed),
#endif
            NoNative(Configuration::Global.flags.NoNative),
            isOptimizedForManyInstances(isOptimizedForManyInstances),
            threadConfig(threadConfig)
        {
        }

        // Version
        bool SupportsES3()                      const { return true; }
        bool SupportsES3Extensions()            const {
#ifdef ENABLE_PROJECTION
            return HostType != HostTypeApplication;
#else
            return true;
#endif
        }

#define FORWARD_THREAD_CONFIG(flag) inline bool flag() const { return threadConfig->flag(); }
#define FLAG(threadFlag, globalFlag) FORWARD_THREAD_CONFIG(threadFlag)
#define FLAG_RELEASE(threadFlag, globalFlag) FORWARD_THREAD_CONFIG(threadFlag)
#include "../Base/ThreadConfigFlagsList.h"
#undef FLAG_RELEASE
#undef FLAG
#undef FORWARD_THREAD_CONFIG

        bool SupportsCollectGarbage() const { return true; }

        void ForceNoNative() { this->NoNative = true; }
        void ForceNative() { this->NoNative = false; }
        bool IsNoNative() const { return this->NoNative; }

        void SetCanOptimizeGlobalLookupFlag(BOOL f){ this->fCanOptimizeGlobalLookup = f;}
        BOOL CanOptimizeGlobalLookup() const { return this->fCanOptimizeGlobalLookup;}
        bool IsOptimizedForManyInstances() const { return isOptimizedForManyInstances; }
        void CopyFrom(ScriptConfiguration& other)
        {
            this->NoNative = other.NoNative;
            this->fCanOptimizeGlobalLookup = other.fCanOptimizeGlobalLookup;
#ifdef ENABLE_PROJECTION
            this->HostType = other.HostType;
            this->WinRTConstructorAllowed = other.WinRTConstructorAllowed;
            this->projectionConfiguration = other.projectionConfiguration;
#endif
        }

#ifdef ENABLE_PROJECTION
        Number GetHostType() const    // Returns one of enum HostType values (see ConfigFlagsTable.h).
        {
            AssertMsg(this->HostType >= HostTypeMin && this->HostType <= HostTypeMax, "HostType value is out of valid range.");
            return this->HostType;
        }

        ProjectionConfiguration const * GetProjectionConfig() const
        {
            return &projectionConfiguration;
        }
        void SetHostType(int32 hostType) { this->HostType = hostType; }
        void SetWinRTConstructorAllowed(bool allowed) { this->WinRTConstructorAllowed = allowed; }
        void SetProjectionTargetVersion(DWORD version)
        {
            projectionConfiguration.SetTargetVersion(version);
        }
        bool IsWinRTEnabled()           const { return (GetHostType() == Js::HostTypeApplication) || (GetHostType() == Js::HostTypeWebview); }

        bool IsWinRTConstructorAllowed() const { return (GetHostType() != Js::HostTypeWebview) || this->WinRTConstructorAllowed; }
#endif
    private:

        // Per script configurations
        bool NoNative;
        BOOL fCanOptimizeGlobalLookup;
        const bool isOptimizedForManyInstances;
        const ThreadConfiguration * const threadConfig;

#ifdef ENABLE_PROJECTION
        Number HostType;    // One of enum HostType values (see ConfigFlagsTable.h).
        bool WinRTConstructorAllowed;  // whether allow constructor in webview host type. Also note that this is not a security feature.
        ProjectionConfiguration projectionConfiguration;
#endif
    };

    struct ScriptEntryExitRecord
    {
        bool hasCaller : 1;
        bool hasReentered : 1;
#if DBG_DUMP
        bool isCallRoot : 1;
#endif
#if DBG || defined(PROFILE_EXEC)
        bool leaveForHost : 1;
#endif
#if DBG
        bool leaveForAsyncHostOperation : 1;
#endif
#ifdef CHECK_STACKWALK_EXCEPTION
        bool ignoreStackWalkException: 1;
#endif
        Js::ImplicitCallFlags savedImplicitCallFlags;

        void * returnAddrOfScriptEntryFunction;
        void * frameIdOfScriptExitFunction; // the frameAddres in x86, the return address in amd64/arm_soc
        ScriptContext * scriptContext;
        struct ScriptEntryExitRecord * next;

#if defined(_M_IX86) && defined(DBG)
        void * scriptEntryFS0;
#endif
#ifdef EXCEPTION_CHECK
        ExceptionType handledExceptionType;
#endif
    };

    static const unsigned int EvalMRUSize = 15;
    typedef JsUtil::BaseDictionary<DWORD_PTR, SourceContextInfo *, Recycler, PowerOf2SizePolicy> SourceContextInfoMap;
    typedef JsUtil::BaseDictionary<uint, SourceContextInfo *, Recycler, PowerOf2SizePolicy> DynamicSourceContextInfoMap;

    typedef JsUtil::BaseDictionary<EvalMapString, ScriptFunction*, RecyclerNonLeafAllocator, PrimeSizePolicy> SecondLevelEvalCache;
    typedef TwoLevelHashRecord<FastEvalMapString, ScriptFunction*, SecondLevelEvalCache, EvalMapString> EvalMapRecord;
    typedef JsUtil::Cache<FastEvalMapString, EvalMapRecord*, RecyclerNonLeafAllocator, PrimeSizePolicy, JsUtil::MRURetentionPolicy<FastEvalMapString, EvalMRUSize>, FastEvalMapStringComparer> EvalCacheTopLevelDictionary;
    typedef JsUtil::Cache<EvalMapString, ParseableFunctionInfo*, RecyclerNonLeafAllocator, PrimeSizePolicy, JsUtil::MRURetentionPolicy<EvalMapString, EvalMRUSize>> NewFunctionCache;
    typedef JsUtil::BaseDictionary<ParseableFunctionInfo*, ParseableFunctionInfo*, Recycler, PrimeSizePolicy, RecyclerPointerComparer> ParseableFunctionInfoMap;
    // This is the dictionary used by script context to cache the eval.
    typedef TwoLevelHashDictionary<FastEvalMapString, ScriptFunction*, EvalMapRecord, EvalCacheTopLevelDictionary, EvalMapString> EvalCacheDictionary;

    struct PropertyStringMap
    {
        PropertyString* strLen2[80];

        inline static uint PStrMapIndex(char16 ch)
        {
            Assert(ch >= '0' && ch <= 'z');
            return ch - '0';
        }
    };

    // valid if object!= NULL
    struct EnumeratedObjectCache {
        static const int kMaxCachedPropStrings=16;
        DynamicObject* object;
        DynamicType* type;
        PropertyString* propertyStrings[kMaxCachedPropStrings];
        int validPropStrings;
    };

    typedef JsUtil::BaseDictionary<JavascriptMethod, JavascriptFunction*, Recycler, PowerOf2SizePolicy> BuiltInLibraryFunctionMap;

    // this is allocated in GC directly to avoid force pinning the object, it is linked from JavascriptLibrary such that it has
    // the same lifetime as JavascriptLibrary, and it can be collected without ScriptContext Close.
    // Allocate it as Finalizable such that it will be still available during JavascriptLibrary Dispose time
    class Cache : public FinalizableObject
    {
    public:
        virtual void Finalize(bool isShutdown) override {}
        virtual void Dispose(bool isShutdown) override {}
        virtual void Mark(Recycler *recycler) override { AssertMsg(false, "Mark called on object that isn't TrackableObject"); }

        JavascriptString * lastNumberToStringRadix10String;
        EnumeratedObjectCache enumObjCache;
        JavascriptString * lastUtcTimeFromStrString;
        EvalCacheDictionary* evalCacheDictionary;
        EvalCacheDictionary* indirectEvalCacheDictionary;
        NewFunctionCache* newFunctionCache;
        RegexPatternMruMap *dynamicRegexMap;
        SourceContextInfoMap* sourceContextInfoMap;   // maps host provided context cookie to the URL of the script buffer passed.
        DynamicSourceContextInfoMap* dynamicSourceContextInfoMap;
        SourceContextInfo* noContextSourceContextInfo;
        SRCINFO* noContextGlobalSourceInfo;
        SRCINFO const ** moduleSrcInfo;
        BuiltInLibraryFunctionMap* builtInLibraryFunctions;
    };

    class ScriptContext : public ScriptContextBase, public ScriptContextInfo
    {
        friend class LowererMD;
        friend class RemoteScriptContext;
        friend class GlobalObject; // InitializeCache
        friend class SourceTextModuleRecord; // for module bytecode gen.

    public:
        static DWORD GetThreadContextOffset() { return offsetof(ScriptContext, threadContext); }
        static DWORD GetOptimizationOverridesOffset() { return offsetof(ScriptContext, optimizationOverrides); }
        static DWORD GetRecyclerOffset() { return offsetof(ScriptContext, recycler); }
        static DWORD GetNumberAllocatorOffset() { return offsetof(ScriptContext, numberAllocator); }
        static DWORD GetAsmIntDbValOffset() { return offsetof(ScriptContext, retAsmIntDbVal); }

        ScriptContext *next;
        ScriptContext *prev;
        double retAsmIntDbVal; // stores the double & float result for Asm interpreter

        AsmJsSIMDValue retAsmSimdVal; // stores raw simd result for Asm interpreter
        static DWORD GetAsmSimdValOffset() { return offsetof(ScriptContext, retAsmSimdVal); }

        ScriptContextOptimizationOverrideInfo optimizationOverrides;

        Js::JavascriptMethod CurrentThunk;
        Js::JavascriptMethod CurrentCrossSiteThunk;
        Js::JavascriptMethod DeferredParsingThunk;
        Js::JavascriptMethod DeferredDeserializationThunk;
        Js::JavascriptMethod DispatchDefaultInvoke;
        Js::JavascriptMethod DispatchProfileInvoke;

#ifdef ENABLE_SCRIPT_DEBUGGING
        typedef HRESULT (*GetDocumentContextFunction)(
            ScriptContext *pContext,
            Js::FunctionBody *pFunctionBody,
            IDebugDocumentContext **ppDebugDocumentContext);
        GetDocumentContextFunction GetDocumentContext;
#endif // ENABLE_SCRIPT_DEBUGGING

#ifdef ENABLE_SCRIPT_PROFILING
        typedef HRESULT (*CleanupDocumentContextFunction)(ScriptContext *pContext);
        CleanupDocumentContextFunction CleanupDocumentContext;
#endif

        const ScriptContextBase* GetScriptContextBase() const { return static_cast<const ScriptContextBase*>(this); }

        bool DoUndeferGlobalFunctions() const;

        bool IsUndeclBlockVar(Var var) const { return this->javascriptLibrary->IsUndeclBlockVar(var); }

        void TrackPid(const PropertyRecord* propertyRecord);
        void TrackPid(PropertyId propertyId);

        bool IsTrackedPropertyId(Js::PropertyId propertyId);
        void InvalidateHostObjects()
        {
            AssertMsg(!isClosed, "Host Object invalidation should occur before the engine is fully closed. Figure our how isClosed got set beforehand.");
            isInvalidatedForHostObjects = true;
        }
        bool IsInvalidatedForHostObjects()
        {
            return isInvalidatedForHostObjects;
        }

#if ENABLE_NATIVE_CODEGEN
        void InitializeRemoteScriptContext();
#endif

#ifdef ENABLE_JS_ETW
        void EmitStackTraceEvent(__in UINT64 operationID, __in USHORT maxFrameCount, bool emitV2AsyncStackEvent);
#endif

        void SetIsDiagnosticsScriptContext(bool set) { this->isDiagnosticsScriptContext = set; }
        bool IsDiagnosticsScriptContext() const { return this->isDiagnosticsScriptContext; }

        bool IsScriptContextInNonDebugMode() const;
        bool IsScriptContextInDebugMode() const;
        bool IsScriptContextInSourceRundownOrDebugMode() const;
        bool IsRunningScript() const { return this->threadContext->GetScriptEntryExit() != nullptr; }

        typedef JsUtil::List<RecyclerWeakReference<Utf8SourceInfo>*, Recycler, false, Js::WeakRefFreeListedRemovePolicy> CalleeSourceList;
        RecyclerRootPtr<CalleeSourceList> calleeUtf8SourceInfoList;
        void AddCalleeSourceInfoToList(Utf8SourceInfo* sourceInfo);
        bool HaveCalleeSources() { return calleeUtf8SourceInfoList && !calleeUtf8SourceInfoList->Empty(); }

        template<class TMapFunction>
        void MapCalleeSources(TMapFunction map)
        {
            if (this->HaveCalleeSources())
            {
                calleeUtf8SourceInfoList->Map([&](uint i, RecyclerWeakReference<Js::Utf8SourceInfo>* sourceInfoWeakRef)
                {
                    if (calleeUtf8SourceInfoList->IsItemValid(i))
                    {
                        Js::Utf8SourceInfo* sourceInfo = sourceInfoWeakRef->Get();
                        map(sourceInfo);
                    }
                });
            }
            if (calleeUtf8SourceInfoList)
            {
                calleeUtf8SourceInfoList.Unroot(this->GetRecycler());
            }
        }

#ifdef ASMJS_PLAT
        inline AsmJsCodeGenerator* GetAsmJsCodeGenerator() const{return asmJsCodeGenerator;}
        AsmJsCodeGenerator* InitAsmJsCodeGenerator();
#endif

        bool IsExceptionWrapperForBuiltInsEnabled();
        static bool IsExceptionWrapperForBuiltInsEnabled(ScriptContext* scriptContext);
        static bool IsExceptionWrapperForHelpersEnabled(ScriptContext* scriptContext);
#ifdef ENABLE_SCRIPT_PROFILING
        bool IsEnumerateNonUserFunctionsOnly() const { return m_enumerateNonUserFunctionsOnly; }
        bool IsTraceDomCall() const { return !!m_fTraceDomCall; }
#endif

        InlineCache * GetValueOfInlineCache() const { return valueOfInlineCache;}
        InlineCache * GetToStringInlineCache() const { return toStringInlineCache; }

        FunctionBody * GetFakeGlobalFuncForUndefer() const { return fakeGlobalFuncForUndefer; }
        void SetFakeGlobalFuncForUndefer(FunctionBody * func) { fakeGlobalFuncForUndefer.Root(func, GetRecycler()); }

    private:
        PropertyStringMap* propertyStrings[80];

        JavascriptFunction* GenerateRootFunction(ParseNodePtr parseTree, uint sourceIndex, Parser* parser, uint32 grfscr, CompileScriptException * pse, const char16 *rootDisplayName);

        typedef void (*EventHandler)(ScriptContext *);
        ScriptContext ** registeredPrototypeChainEnsuredToHaveOnlyWritableDataPropertiesScriptContext;

        ArenaAllocator generalAllocator;
#ifdef ENABLE_BASIC_TELEMETRY
        ArenaAllocator telemetryAllocator;
#endif

        ArenaAllocator dynamicProfileInfoAllocator;
        InlineCacheAllocator inlineCacheAllocator;
        CacheAllocator isInstInlineCacheAllocator;
        CacheAllocator forInCacheAllocator;

        ArenaAllocator* interpreterArena;
        ArenaAllocator* guestArena;

        ArenaAllocator* diagnosticArena;

        intptr_t m_remoteScriptContextAddr;

        bool startupComplete; // Indicates if the heuristic startup phase for this script context is complete
        bool isInvalidatedForHostObjects;  // Indicates that we've invalidate all objects in the host so stop calling them.
        bool isEnumeratingRecyclerObjects; // Indicates this scriptContext is enumerating recycler objects. Used by recycler enumerating callbacks to filter out other unrelated scriptContexts.
        bool m_enumerateNonUserFunctionsOnly; // Indicates that recycler enumeration callback will consider only non-user functions (which are built-ins, external, winrt etc).

        ThreadContext* threadContext;
        TypeId  directHostTypeId;

        InlineCache * valueOfInlineCache;
        InlineCache * toStringInlineCache;

        typedef JsUtil::BaseHashSet<Js::PropertyId, ArenaAllocator> PropIdSetForConstProp;
        PropIdSetForConstProp * intConstPropsOnGlobalObject;
        PropIdSetForConstProp * intConstPropsOnGlobalUserObject;

        void * firstInterpreterFrameReturnAddress;
#ifdef SEPARATE_ARENA
        ArenaAllocator sourceCodeAllocator;
        ArenaAllocator regexAllocator;
#endif
#ifdef NEED_MISC_ALLOCATOR
        ArenaAllocator miscAllocator;
#endif

#if DBG
        JsUtil::BaseHashSet<void *, ArenaAllocator> bindRef;
        int m_iProfileSession;
#endif

#ifdef PROFILE_EXEC
        ScriptContextProfiler * profiler;
        bool isProfilerCreated;
        bool disableProfiler;
        bool ensureParentInfo;

        Profiler * CreateProfiler();
#endif
#ifdef PROFILE_MEM
        bool profileMemoryDump;
#endif
#ifdef PROFILE_STRINGS
        StringProfiler* stringProfiler;
#endif

        RecyclerRootPtr<FunctionBody> fakeGlobalFuncForUndefer;

public:
#ifdef PROFILE_TYPES
        int convertNullToSimpleCount;
        int convertNullToSimpleDictionaryCount;
        int convertNullToDictionaryCount;
        int convertDeferredToDictionaryCount;
        int convertDeferredToSimpleDictionaryCount;
        int convertSimpleToDictionaryCount;
        int convertSimpleToSimpleDictionaryCount;
        int convertPathToDictionaryCount1;
        int convertPathToDictionaryCount2;
        int convertPathToDictionaryCount3;
        int convertPathToDictionaryCount4;
        int convertPathToSimpleDictionaryCount;
        int convertSimplePathToPathCount;
        int convertSimpleDictionaryToDictionaryCount;
        int convertSimpleSharedDictionaryToNonSharedCount;
        int convertSimpleSharedToNonSharedCount;
        int simplePathTypeHandlerCount;
        int pathTypeHandlerCount;
        int promoteCount;
        int cacheCount;
        int branchCount;
        int maxPathLength;
        int typeCount[TypeIds_Limit];
        int instanceCount[TypeIds_Limit];
#endif


#ifdef PROFILE_BAILOUT_RECORD_MEMORY
        __int64 bailOutRecordBytes;
        __int64 bailOutOffsetBytes;
        __int64 codeSize;
#endif

#ifdef  PROFILE_OBJECT_LITERALS
        int objectLiteralInstanceCount;
        int objectLiteralPathCount;
        int objectLiteralCount[TypePath::MaxPathTypeHandlerLength];
        int objectLiteralSimpleDictionaryCount;
        uint32 objectLiteralMaxLength;
        int objectLiteralPromoteCount;
        int objectLiteralCacheCount;
        int objectLiteralBranchCount;
#endif
#if DBG_DUMP
        uint byteCodeDataSize;
        uint byteCodeAuxiliaryDataSize;
        uint byteCodeAuxiliaryContextDataSize;
        uint byteCodeHistogram[static_cast<uint>(OpCode::ByteCodeLast)];
        uint32 forinCache;
        uint32 forinNoCache;
#endif
#ifdef BGJIT_STATS
        uint interpretedCount;
        uint funcJITCount;
        uint loopJITCount;
        uint bytecodeJITCount;
        uint interpretedCallsHighPri;
        uint maxFuncInterpret;
        uint jitCodeUsed;
        uint funcJitCodeUsed;
        uint speculativeJitCount;
#endif

#ifdef REJIT_STATS
        // Used to store bailout stats
        typedef JsUtil::BaseDictionary<uint, uint, ArenaAllocator> BailoutStatsMap;

        struct RejitStats
        {
            uint *m_rejitReasonCounts;
            BailoutStatsMap* m_bailoutReasonCounts;

            uint  m_totalRejits;
            uint  m_totalBailouts;

            RejitStats(ScriptContext *scriptContext) : m_totalRejits(0), m_totalBailouts(0)
            {
                m_rejitReasonCounts = AnewArrayZ(scriptContext->GeneralAllocator(), uint, NumRejitReasons);
                m_bailoutReasonCounts = Anew(scriptContext->GeneralAllocator(), BailoutStatsMap, scriptContext->GeneralAllocator());
            }
        };

        void LogDataForFunctionBody(Js::FunctionBody *body, uint idx, bool isRejit);

        void LogRejit(Js::FunctionBody *body, uint reason);
        void LogBailout(Js::FunctionBody *body, uint kind);

        // Used to centrally collect stats for all function bodies.
        typedef JsUtil::WeaklyReferencedKeyDictionary<const Js::FunctionBody, RejitStats*> RejitStatsMap;
        RejitStatsMap* rejitStatsMap;

        BailoutStatsMap *bailoutReasonCounts;
        uint *rejitReasonCounts;
#endif
#ifdef ENABLE_BASIC_TELEMETRY

    private:
        ScriptContextTelemetry* telemetry;
    public:
        ScriptContextTelemetry& GetTelemetry();
        bool HasTelemetry();

#endif
#ifdef INLINE_CACHE_STATS
        // Used to store inline cache stats

        struct CacheData
        {
            uint hits;
            uint misses;
            uint collisions;
            bool isGetCache;
            Js::PropertyId propertyId;

            CacheData() : hits(0), misses(0), collisions(0), isGetCache(false), propertyId(Js::PropertyIds::_none) { }
        };

        // This is a strongly referenced dictionary, since we want to know hit rates for dead caches.
        typedef JsUtil::BaseDictionary<const Js::PolymorphicInlineCache*, CacheData*, Recycler> CacheDataMap;
        CacheDataMap *cacheDataMap;

        void LogCacheUsage(Js::PolymorphicInlineCache *cache, bool isGet, Js::PropertyId propertyId, bool hit, bool collision);
#endif

#ifdef FIELD_ACCESS_STATS
        typedef SList<FieldAccessStatsPtr, Recycler> FieldAccessStatsList;

        struct FieldAccessStatsEntry
        {
            RecyclerWeakReference<FunctionBody>* functionBodyWeakRef;
            FieldAccessStatsList stats;

            FieldAccessStatsEntry(RecyclerWeakReference<FunctionBody>* functionBodyWeakRef, Recycler* recycler)
                : functionBodyWeakRef(functionBodyWeakRef), stats(recycler) {}
        };

        typedef JsUtil::BaseDictionary<uint, FieldAccessStatsEntry*, Recycler> FieldAccessStatsByFunctionNumberMap;

        FieldAccessStatsByFunctionNumberMap* fieldAccessStatsByFunctionNumber;

        void RecordFieldAccessStats(FunctionBody* functionBody, FieldAccessStatsPtr fieldAccessStats);
#endif

#ifdef MISSING_PROPERTY_STATS
        int missingPropertyMisses;
        int missingPropertyHits;
        int missingPropertyCacheAttempts;

        void RecordMissingPropertyMiss();
        void RecordMissingPropertyHit();
        void RecordMissingPropertyCacheAttempt();
#endif

        bool IsIntConstPropertyOnGlobalObject(Js::PropertyId propId);
        void TrackIntConstPropertyOnGlobalObject(Js::PropertyId propId);
        bool IsIntConstPropertyOnGlobalUserObject(Js::PropertyId propertyId);
        void TrackIntConstPropertyOnGlobalUserObject(Js::PropertyId propertyId);

private:
        //
        // Regex globals
        //
#if ENABLE_REGEX_CONFIG_OPTIONS
        UnifiedRegex::DebugWriter* regexDebugWriter;
        UnifiedRegex::RegexStatsDatabase* regexStatsDatabase;
#endif
        UnifiedRegex::TrigramAlphabet* trigramAlphabet;
        UnifiedRegex::RegexStacks *regexStacks;

        JsUtil::Stack<Var>* operationStack;
        Recycler* recycler;
        RecyclerJavascriptNumberAllocator numberAllocator;

        ScriptConfiguration config;
        CharClassifier *charClassifier;

        // DisableJIT-TODO: Switch this to Dynamic thunk ifdef instead
#if ENABLE_NATIVE_CODEGEN
#if DYNAMIC_INTERPRETER_THUNK
        InterpreterThunkEmitter* interpreterThunkEmitter;
#endif
        BackgroundParser *backgroundParser;
#ifdef ASMJS_PLAT
        InterpreterThunkEmitter* asmJsInterpreterThunkEmitter;
        AsmJsCodeGenerator* asmJsCodeGenerator;
        typedef JsUtil::BaseDictionary<void *, SList<AsmJsScriptFunction *>*, ArenaAllocator> AsmFunctionMap;
        AsmFunctionMap* asmJsEnvironmentMap;
        ArenaAllocator* debugTransitionAlloc;
#endif
        NativeCodeGenerator* nativeCodeGen;
#endif

        DateTime::DaylightTimeHelper daylightTimeHelper;
        DateTime::Utility dateTimeUtility;

public:
        inline const WCHAR *const GetStandardName(size_t *nameLength, DateTime::YMD *ymd = NULL)
        {
            return dateTimeUtility.GetStandardName(nameLength, ymd);
        }

        inline const WCHAR *const GetDaylightName(size_t *nameLength, DateTime::YMD *ymd = NULL)
        {
            return dateTimeUtility.GetDaylightName(nameLength, ymd);
        }

private:
        HostScriptContext * hostScriptContext;
        HaltCallback* scriptEngineHaltCallback;
        EventHandler scriptStartEventHandler;
        EventHandler scriptEndEventHandler;
#ifdef FAULT_INJECTION
        EventHandler disposeScriptByFaultInjectionEventHandler;
#endif

        JsUtil::BaseDictionary<uint, JavascriptString *, ArenaAllocator> integerStringMap;

        double lastNumberToStringRadix10;
        double lastUtcTimeFromStr;

#if ENABLE_PROFILE_INFO
        bool referencesSharedDynamicSourceContextInfo;
#endif

        // We could delay the actual close after callRootLevel is 0.
        // this is to indicate the actual close is called once only.
        bool isScriptContextActuallyClosed;
        bool isFinalized;
#if DBG
        bool isInitialized;
        bool isCloningGlobal;
#endif
        bool fastDOMenabled;
        bool hasUsedInlineCache;
        bool hasProtoOrStoreFieldInlineCache;
        bool hasIsInstInlineCache;
        bool deferredBody;
        bool isPerformingNonreentrantWork;
        bool isDiagnosticsScriptContext;   // mentions that current script context belongs to the diagnostics OM.

        size_t sourceSize;

        void CleanSourceListInternal(bool calledDuringMark);
        typedef JsUtil::List<RecyclerWeakReference<Utf8SourceInfo>*, Recycler, false, Js::FreeListedRemovePolicy> SourceList;
        RecyclerRootPtr<SourceList> sourceList;

#ifdef ENABLE_SCRIPT_PROFILING
        IActiveScriptProfilerHeapEnum* heapEnum;

        // Profiler Probes
        // In future these can be list of callbacks ?
        // Profiler Callback information
        IActiveScriptProfilerCallback *m_pProfileCallback;
        BOOL m_fTraceFunctionCall;
        BOOL m_fTraceNativeFunctionCall;
        DWORD m_dwEventMask;

        IActiveScriptProfilerCallback2 *m_pProfileCallback2;
        BOOL m_fTraceDomCall;
        BOOL m_inProfileCallback;
#endif // ENABLE_SCRIPT_PROFILING

#if ENABLE_PROFILE_INFO
#if DBG_DUMP || defined(DYNAMIC_PROFILE_STORAGE) || defined(RUNTIME_DATA_COLLECTION)
        RecyclerRootPtr<SListBase<DynamicProfileInfo *>> profileInfoList;
#endif
#endif
        // List of weak reference dictionaries. We'll walk through them
        // and clean them up post-collection
        // IWeakReferenceDictionary objects are added to this list by calling
        // RegisterWeakReferenceDictionary. If you use JsUtil::WeakReferenceDictionary,
        // which also exposes the IWeakReferenceDictionary interface, it'll
        // automatically register the dictionary on the script context
        SListBase<JsUtil::IWeakReferenceDictionary*> weakReferenceDictionaryList;
        bool isWeakReferenceDictionaryListCleared;

        typedef void(*RaiseMessageToDebuggerFunctionType)(ScriptContext *, DEBUG_EVENT_INFO_TYPE, LPCWSTR, LPCWSTR);
        RaiseMessageToDebuggerFunctionType raiseMessageToDebuggerFunctionType;

        typedef void(*TransitionToDebugModeIfFirstSourceFn)(ScriptContext *, Utf8SourceInfo *);
        TransitionToDebugModeIfFirstSourceFn transitionToDebugModeIfFirstSourceFn;

        ScriptContext(ThreadContext* threadContext);
        void InitializeAllocations();
        void InitializePreGlobal();
        void InitializePostGlobal();
        void InitializeCache();

        // Source Info
        void EnsureSourceContextInfoMap();
        void EnsureDynamicSourceContextInfoMap();

        uint moduleSrcInfoCount;
#ifdef RUNTIME_DATA_COLLECTION
        time_t createTime;
#endif
        char16 const * url;

        void PrintStats();
        BOOL LeaveScriptStartCore(void * frameAddress, bool leaveForHost);

        void InternalClose();

        DebugContext* debugContext;
        CriticalSection debugContextCloseCS;

    public:
        static const int kArrayMatchCh=72;
        static const int kMaxArrayMatchIndex=8192;
        short arrayMatchItems[kArrayMatchCh];
        bool arrayMatchInit;

#ifdef LEAK_REPORT
        LeakReport::UrlRecord * urlRecord;
        bool isRootTrackerScriptContext;
#endif

        DateTime::DaylightTimeHelper *GetDaylightTimeHelper() { return &daylightTimeHelper; }
        DateTime::Utility *GetDateUtility() { return &dateTimeUtility; }

        virtual bool IsClosed() const override { return isClosed; }
        void SetIsClosed();

        bool IsFinalized() const { return isFinalized; }
        void SetIsFinalized() { isFinalized = true; }
        bool IsActuallyClosed() const { return isScriptContextActuallyClosed; }
#if ENABLE_NATIVE_CODEGEN
        bool IsClosedNativeCodeGenerator() const
        {
            return !nativeCodeGen || ::IsClosedNativeCodeGenerator(nativeCodeGen);
        }
#endif

        void SetHasUsedInlineCache(bool value) { hasUsedInlineCache = value; }

        void SetDirectHostTypeId(TypeId typeId) {directHostTypeId = typeId; }
        TypeId GetDirectHostTypeId() const { return directHostTypeId; }

        intptr_t GetRemoteScriptAddr(bool allowInitialize = true) 
        {
#if ENABLE_OOP_NATIVE_CODEGEN
            if (!m_remoteScriptContextAddr && allowInitialize)
            {
                InitializeRemoteScriptContext();
            }
#endif
            return m_remoteScriptContextAddr; 
        }

        char16 const * GetUrl() const { return url; }
        void SetUrl(BSTR bstr);
#ifdef RUNTIME_DATA_COLLECTION
        time_t GetCreateTime() const { return createTime; }
        uint GetAllocId() const { return allocId; }
#endif
        void InitializeArrayMatch()
        {
            if (!arrayMatchInit)
            {
                for (int i=0;i<kArrayMatchCh;i++)
                {
                    arrayMatchItems[i]= -1;
                }
                arrayMatchInit=true;
            }
        }

#ifdef HEAP_ENUMERATION_VALIDATION
        bool IsInitialized() { return this->isInitialized; }
#endif

        DebugContext* GetDebugContext() const { return this->debugContext; }
        CriticalSection* GetDebugContextCloseCS() { return &debugContextCloseCS; }

        uint callCount;

        // Guest arena allocated cache holding references that need to be pinned.
        Cache* cache;

        // if the current context is for webworker
        DWORD webWorkerId;

        static ScriptContext * New(ThreadContext * threadContext);
        static void Delete(ScriptContext* scriptContext);

        ~ScriptContext();

#ifdef PROFILE_TYPES
        void ProfileTypes();
#endif

#ifdef PROFILE_OBJECT_LITERALS
        void ProfileObjectLiteral();
#endif

        //
        // Regex helpers
        //
#if ENABLE_REGEX_CONFIG_OPTIONS
        UnifiedRegex::RegexStatsDatabase* GetRegexStatsDatabase();
        UnifiedRegex::DebugWriter* GetRegexDebugWriter();
#endif
        RegexPatternMruMap* GetDynamicRegexMap() const;

        UnifiedRegex::TrigramAlphabet* GetTrigramAlphabet() { return trigramAlphabet; }

        void SetTrigramAlphabet(UnifiedRegex::TrigramAlphabet * trigramAlphabet);

        UnifiedRegex::RegexStacks *RegexStacks();
        UnifiedRegex::RegexStacks *AllocRegexStacks();
        UnifiedRegex::RegexStacks *SaveRegexStacks();
        void RestoreRegexStacks(UnifiedRegex::RegexStacks *const contStack);

        void InitializeGlobalObject();
        bool IsIntlEnabled();
        JavascriptLibrary* GetLibrary() const { return javascriptLibrary; }
        const JavascriptLibraryBase* GetLibraryBase() const { return javascriptLibrary->GetLibraryBase(); }
#if DBG
        BOOL IsCloningGlobal() const { return isCloningGlobal;}
#endif
        void PushObject(Var object);
        Var PopObject();
        BOOL CheckObject(Var object);

        inline bool IsHeapEnumInProgress() { return GetRecycler()->IsHeapEnumInProgress(); }

        bool IsInterpreted() { return config.IsNoNative(); }
        void ForceNoNative() { config.ForceNoNative(); }
        void ForceNative() { config.ForceNative(); }
        ScriptConfiguration const * GetConfig(void) const { return &config; }
        CharClassifier const * GetCharClassifier(void) const;

        ThreadContext * GetThreadContext() const { return threadContext; }

        static const int MaxEvalSourceSize = 400;

        bool IsInEvalMap(FastEvalMapString const& key, BOOL isIndirect, ScriptFunction **ppFuncScript);
        void AddToEvalMap(FastEvalMapString const& key, BOOL isIndirect, ScriptFunction *pFuncScript);

        template <typename TCacheType>
        void CleanDynamicFunctionCache(TCacheType* cacheType);
        void CleanEvalMapCache(Js::EvalCacheTopLevelDictionary * cacheType);

        template <class TDelegate>
        void MapFunction(TDelegate mapper);

        template <class TDelegate>
        FunctionBody* FindFunction(TDelegate predicate);

        inline bool EnableEvalMapCleanup() { return CONFIG_FLAG(EnableEvalMapCleanup); };
        uint GetNextSourceContextId();

        bool IsInNewFunctionMap(EvalMapString const& key, ParseableFunctionInfo **ppFuncBody);
        void AddToNewFunctionMap(EvalMapString const& key, ParseableFunctionInfo *pFuncBody);

        SourceContextInfo * GetSourceContextInfo(DWORD_PTR hostSourceContext, IActiveScriptDataCache* profileDataCache);
        SourceContextInfo * GetSourceContextInfo(uint hash);
        SourceContextInfo * CreateSourceContextInfo(uint hash, DWORD_PTR hostSourceContext);
        SourceContextInfo * CreateSourceContextInfo(DWORD_PTR hostSourceContext, char16 const * url, size_t len,
            IActiveScriptDataCache* profileDataCache, char16 const * sourceMapUrl = nullptr, size_t sourceMapUrlLen = 0);

#if defined(LEAK_REPORT) || defined(CHECK_MEMORY_LEAK)
        void ClearSourceContextInfoMaps()
        {
          if (this->cache != nullptr)
          {
              this->cache->sourceContextInfoMap = nullptr;
              this->cache->dynamicSourceContextInfoMap = nullptr;
#if ENABLE_PROFILE_INFO
              this->referencesSharedDynamicSourceContextInfo = false;
#endif
          }
        }
#endif

#if ENABLE_PROFILE_INFO
#if DBG_DUMP || defined(DYNAMIC_PROFILE_STORAGE) || defined(RUNTIME_DATA_COLLECTION)
        void ClearDynamicProfileList()
        {
            if (profileInfoList)
            {
                profileInfoList->Reset();
                profileInfoList.Unroot(this->recycler);
            }
        }

        SListBase<DynamicProfileInfo *> * GetProfileInfoList() { return profileInfoList; }
#endif
#endif

        SRCINFO const * GetModuleSrcInfo(Js::ModuleID moduleID);
        SourceContextInfoMap* GetSourceContextInfoMap()
        {
            return (this->cache ? this->cache->sourceContextInfoMap : nullptr);
        }
        DynamicSourceContextInfoMap* GetDynamicSourceContextInfoMap()
        {
            return (this->cache ? this->cache->dynamicSourceContextInfoMap : nullptr);
        }

#if ENABLE_TTD
        //The host callback functor info
        HostScriptContextCallbackFunctor TTDHostCallbackFunctor;

        //The TTDMode for this script context (the same as the Mode for the thread context but we put it here for fast lookup when identity tagging)
        TTD::TTDMode TTDMode;

        //The LogTag for this script context (the same as the tag for the global object but we put it here for fast lookup)
        TTD_LOG_PTR_ID ScriptContextLogTag;

        //Keep track of the number of re-entrant calls currently pending (i.e., if we make an external call it may call back into Chakra)
        int32 TTDRootNestingCount;

        //Info about the core image for the context
        TTD::RuntimeContextInfo* TTDWellKnownInfo;

        //Additional runtime context that we only care about if TTD is running (or will be running)
        TTD::ScriptContextTTD* TTDContextInfo;

        ////

        //Use this to check specifically if we are in record AND this code is being run on behalf of the user application
        bool ShouldPerformRecordAction() const
        {
            //return true if RecordEnabled and ~ExcludedExecution
            return (this->TTDMode & TTD::TTDMode::TTDShouldRecordActionMask) == TTD::TTDMode::RecordEnabled;
        }

        //Use this to check specifically if we are in debugging mode AND this code is being run on behalf of the user application
        bool ShouldPerformDebugAction() const
        {
#if ENABLE_TTD_DEBUGGING
            //return true if DebuggingEnabled and ~ExcludedExecution
            return (this->TTDMode & TTD::TTDMode::TTDShouldDebugActionMask) == TTD::TTDMode::DebuggingEnabled;

#else
            return false;
#endif
        }

        //Use this to check if the TTD has been set into record/replay mode (although we still need to check if we should do any record ro replay)
        bool IsTTDActive() const
        {
            return (this->TTDMode & TTD::TTDMode::TTDActive) != TTD::TTDMode::Invalid;
        }

        //Use this to check if the TTD has been detached (e.g., has traced a context execution and has now been detached)
        bool IsTTDDetached() const
        {
            return (this->TTDMode & TTD::TTDMode::Detached) != TTD::TTDMode::Invalid;
        }

        //
        //TODO: there is a memory leak associated with this we need to relax later
        //
        //A special record check because we want to pin weak references even if we aren't actively logging (but are planning to do so in the future)
        bool ShouldPerformWeakRefPinAction() const
        {
            bool modeIsPending = (this->TTDMode & TTD::TTDMode::Pending) == TTD::TTDMode::Pending;
            bool modeIsRecord = (this->TTDMode & TTD::TTDMode::RecordEnabled) == TTD::TTDMode::RecordEnabled;
            bool modeIsDebugging = (this->TTDMode & TTD::TTDMode::DebuggingEnabled) == TTD::TTDMode::DebuggingEnabled;
            bool inDebugableCode = (this->TTDMode & TTD::TTDMode::ExcludedExecution) == TTD::TTDMode::Invalid;

            return ((modeIsPending | modeIsRecord | modeIsDebugging) & inDebugableCode);
        }

        //A special record check because we want to record code load even if we aren't actively logging (but are planning to do so in the future)
        bool ShouldPerformRecordTopLevelFunction() const
        {
            bool modeIsPending = (this->TTDMode & TTD::TTDMode::Pending) == TTD::TTDMode::Pending;
            bool modeIsRecord = (this->TTDMode & TTD::TTDMode::RecordEnabled) == TTD::TTDMode::RecordEnabled;
            bool inDebugableCode = (this->TTDMode & TTD::TTDMode::ExcludedExecution) == TTD::TTDMode::Invalid;

            return ((modeIsPending | modeIsRecord) & inDebugableCode);
        }

        //A special record check because we want to record root add/remove ref even if we aren't actively logging (but are planning to do so in the future)
        bool ShouldPerformRootAddOrRemoveRefAction() const
        {
            bool modeIsPending = (this->TTDMode & TTD::TTDMode::Pending) == TTD::TTDMode::Pending;
            bool modeIsRecord = (this->TTDMode & TTD::TTDMode::RecordEnabled) == TTD::TTDMode::RecordEnabled;
            bool inDebugableCode = (this->TTDMode & TTD::TTDMode::ExcludedExecution) == TTD::TTDMode::Invalid;

            return ((modeIsPending | modeIsRecord) & inDebugableCode);
        }

        //A special record check because we want to take action on async buffer registration and completion even if we have not started actively logging (but are planning to do so in the future)
        bool ShouldPerformAsyncBufferModAction() const
        {
            bool modeIsPending = (this->TTDMode & TTD::TTDMode::Pending) == TTD::TTDMode::Pending;
            bool modeIsRecord = (this->TTDMode & TTD::TTDMode::RecordEnabled) == TTD::TTDMode::RecordEnabled;
            bool inDebugableCode = (this->TTDMode & TTD::TTDMode::ExcludedExecution) == TTD::TTDMode::Invalid;

            return ((modeIsPending | modeIsRecord) & inDebugableCode);
        }

        //A special check for to see if we want to push the supression flag for getter exection
        bool ShouldDoGetterInvocationSupression() const
        {
#if !ENABLE_TTD_DEBUGGING
            return false;
#else
            return (this->TTDMode & TTD::TTDMode::DebuggingEnabled) == TTD::TTDMode::DebuggingEnabled;
#endif
        }

        //A special check to see if we are debugging and want to suppress the execution of getters when displaying values in the debugger
        bool ShouldSuppressGetterInvocationForDebuggerEvaluation() const
        {
#if !ENABLE_TTD_DEBUGGING
            return false;
#else
            return (this->TTDMode & TTD::TTDMode::TTDShouldSupressGetterActionMask) == TTD::TTDMode::TTDShouldSupressGetterActionMask;
#endif
        }

        //A special check to see if we are in the process of a time-travel move and do not want to stop at any breakpoints
        bool ShouldSuppressBreakpointsForTimeTravelMove() const
        {
#if !ENABLE_TTD_DEBUGGING
            return false;
#else
            return (this->TTDMode & TTD::TTDMode::DebuggerSuppressBreakpoints) == TTD::TTDMode::DebuggerSuppressBreakpoints;
#endif
        }

        //A special check to see if we are in the process of a time-travel move and do not want to stop at any breakpoints
        bool ShouldRecordBreakpointsDuringTimeTravelScan() const
        {
#if !ENABLE_TTD_DEBUGGING
            return false;
#else
            return (this->TTDMode & TTD::TTDMode::DebuggerLogBreakpoints) == TTD::TTDMode::DebuggerLogBreakpoints;
#endif
        }

        //
        //TODO: this is currently called explicitly -- we need to fix up the core image computation and this will be eliminated then
        //
        //Initialize the core object image for TTD
        void InitializeCoreImage_TTD();

        //Initialize debug script generation and no-native as needed for replay/debug at script context initialization
        void InitializeRecordingActionsAsNeeded_TTD();
        void InitializeDebuggingActionsAsNeeded_TTD();
#endif

        void SetFirstInterpreterFrameReturnAddress(void * returnAddress) { firstInterpreterFrameReturnAddress = returnAddress;}
        void *GetFirstInterpreterFrameReturnAddress() { return firstInterpreterFrameReturnAddress;}

        void CleanupWeakReferenceDictionaries();

        void Initialize();
        bool Close(bool inDestructor);
        void MarkForClose();
#ifdef ENABLE_PROJECTION
        void SetHostType(int32 hostType) { config.SetHostType(hostType); }
        void SetWinRTConstructorAllowed(bool allowed) { config.SetWinRTConstructorAllowed(allowed); }
        void SetProjectionTargetVersion(DWORD version) { config.SetProjectionTargetVersion(version); }
#endif
        void SetCanOptimizeGlobalLookupFlag(BOOL f){ config.SetCanOptimizeGlobalLookupFlag(f);}
        BOOL CanOptimizeGlobalLookup(){ return config.CanOptimizeGlobalLookup();}

        bool IsFastDOMEnabled() { return fastDOMenabled; }
        void SetFastDOMenabled();
        BOOL VerifyAlive(BOOL isJSFunction = FALSE, ScriptContext* requestScriptContext = nullptr);
        void VerifyAliveWithHostContext(BOOL isJSFunction, HostScriptContext* requestHostScriptContext);
        void AddFunctionBodyToPropIdMap(FunctionBody* body);

        void BindReference(void* addr);

        void InitPropertyStringMap(int i);
        PropertyString* AddPropertyString2(const Js::PropertyRecord* propertyRecord);
        PropertyString* CachePropertyString2(const Js::PropertyRecord* propertyRecord);
        PropertyString* GetPropertyString2(char16 ch1, char16 ch2);
        void FindPropertyRecord(__in LPCWSTR pszPropertyName, __in int propertyNameLength, PropertyRecord const** propertyRecord);
        JsUtil::List<const RecyclerWeakReference<Js::PropertyRecord const>*>* FindPropertyIdNoCase(__in LPCWSTR pszPropertyName, __in int propertyNameLength);

        void FindPropertyRecord(JavascriptString* pstName, PropertyRecord const** propertyRecord);
        PropertyRecord const * GetPropertyName(PropertyId propertyId);
        PropertyRecord const * GetPropertyNameLocked(PropertyId propertyId);
        void GetOrAddPropertyRecord(JsUtil::CharacterBuffer<WCHAR> const& propName, PropertyRecord const** propertyRecord);
        template <size_t N> void GetOrAddPropertyRecord(const char16(&propertyName)[N], PropertyRecord const** propertyRecord)
        {
            GetOrAddPropertyRecord(propertyName, N - 1, propertyRecord);
        }
        PropertyId GetOrAddPropertyIdTracked(JsUtil::CharacterBuffer<WCHAR> const& propName);
        template <size_t N> PropertyId GetOrAddPropertyIdTracked(const char16(&propertyName)[N])
        {
            return GetOrAddPropertyIdTracked(propertyName, N - 1);
        }
        PropertyId GetOrAddPropertyIdTracked(__in_ecount(propertyNameLength) LPCWSTR pszPropertyName, __in int propertyNameLength);
        void GetOrAddPropertyRecord(__in_ecount(propertyNameLength) LPCWSTR pszPropertyName, __in int propertyNameLength, PropertyRecord const** propertyRecord);
        BOOL IsNumericPropertyId(PropertyId propertyId, uint32* value);

        void RegisterWeakReferenceDictionary(JsUtil::IWeakReferenceDictionary* weakReferenceDictionary);
        void ResetWeakReferenceDictionaryList() { weakReferenceDictionaryList.Reset(); }

        BOOL ReserveStaticTypeIds(__in int first, __in int last);
        TypeId ReserveTypeIds(int count);
        TypeId CreateTypeId();

        WellKnownHostType GetWellKnownHostType(Js::TypeId typeId) { return threadContext->GetWellKnownHostType(typeId); }
        void SetWellKnownHostTypeId(WellKnownHostType wellKnownType, Js::TypeId typeId) { threadContext->SetWellKnownHostTypeId(wellKnownType, typeId); }

        ParseNodePtr ParseScript(Parser* parser, const byte* script, size_t cb, SRCINFO const * pSrcInfo,
            CompileScriptException * pse, Utf8SourceInfo** ppSourceInfo, const char16 *rootDisplayName, LoadScriptFlag loadScriptFlag, uint* sourceIndex);
        JavascriptFunction* LoadScript(const byte* script, size_t cb, SRCINFO const * pSrcInfo,
            CompileScriptException * pse, Utf8SourceInfo** ppSourceInfo, const char16 *rootDisplayName, LoadScriptFlag loadScriptFlag);

        ArenaAllocator* GeneralAllocator() { return &generalAllocator; }

#ifdef ENABLE_BASIC_TELEMETRY
        ArenaAllocator* TelemetryAllocator() { return &telemetryAllocator; }
#endif

#ifdef SEPARATE_ARENA
        ArenaAllocator* SourceCodeAllocator() { return &sourceCodeAllocator; }
        ArenaAllocator* RegexAllocator() { return &regexAllocator; }
#else
        ArenaAllocator* SourceCodeAllocator() { return &generalAllocator; }
        ArenaAllocator* RegexAllocator() { return &generalAllocator; }
#endif
#ifdef NEED_MISC_ALLOCATOR
        ArenaAllocator* MiscAllocator() { return &miscAllocator; }
#endif
        InlineCacheAllocator* GetInlineCacheAllocator() { return &inlineCacheAllocator; }
        CacheAllocator* GetIsInstInlineCacheAllocator() { return &isInstInlineCacheAllocator; }
        CacheAllocator * ForInCacheAllocator() { return &forInCacheAllocator; }
        ArenaAllocator* DynamicProfileInfoAllocator() { return &dynamicProfileInfoAllocator; }

        ArenaAllocator* AllocatorForDiagnostics();

        Js::TempArenaAllocatorObject* GetTemporaryAllocator(LPCWSTR name);
        void ReleaseTemporaryAllocator(Js::TempArenaAllocatorObject* tempAllocator);
        Js::TempGuestArenaAllocatorObject* GetTemporaryGuestAllocator(LPCWSTR name);
        void ReleaseTemporaryGuestAllocator(Js::TempGuestArenaAllocatorObject* tempAllocator);

        bool EnsureInterpreterArena(ArenaAllocator **);
        void ReleaseInterpreterArena();

        ArenaAllocator* GetGuestArena() const
        {
            return guestArena;
        }

        void ReleaseGuestArena();

        Recycler* GetRecycler() const { return recycler; }
        RecyclerJavascriptNumberAllocator * GetNumberAllocator() { return &numberAllocator; }
#if ENABLE_NATIVE_CODEGEN
        NativeCodeGenerator * GetNativeCodeGenerator() const { return nativeCodeGen; }
#endif
#if ENABLE_BACKGROUND_PARSING
        BackgroundParser * GetBackgroundParser() const { return backgroundParser; }
#endif

        void OnScriptStart(bool isRoot, bool isScript);
        void OnScriptEnd(bool isRoot, bool isForcedEnd);

        template <bool stackProbe, bool leaveForHost>
        bool LeaveScriptStart(void * frameAddress);
        template <bool leaveForHost>
        void LeaveScriptEnd(void * frameAddress);

        HostScriptContext * GetHostScriptContext() const { return hostScriptContext; }
        void SetHostScriptContext(HostScriptContext *  hostScriptContext);
        void SetScriptEngineHaltCallback(HaltCallback* scriptEngine);
        void ClearHostScriptContext();

        IActiveScriptProfilerHeapEnum* GetHeapEnum();
        void SetHeapEnum(IActiveScriptProfilerHeapEnum* newHeapEnum);
        void ClearHeapEnum();

        void SetScriptStartEventHandler(EventHandler eventHandler);
        void SetScriptEndEventHandler(EventHandler eventHandler);
#ifdef FAULT_INJECTION
        void DisposeScriptContextByFaultInjection();
        void SetDisposeDisposeByFaultInjectionEventHandler(EventHandler eventHandler);
#endif
        EnumeratedObjectCache* GetEnumeratedObjectCache() { return &(cache->enumObjCache); }
        PropertyString* TryGetPropertyString(PropertyId propertyId);
        PropertyString* GetPropertyString(PropertyId propertyId);
        void InvalidatePropertyStringCache(PropertyId propertyId, Type* type);
        JavascriptString* GetIntegerString(Var aValue);
        JavascriptString* GetIntegerString(int value);
        JavascriptString* GetIntegerString(uint value);

        void CheckEvalRestriction();

        RecyclableObject* GetMissingPropertyResult();
        RecyclableObject* GetMissingItemResult();

        bool HasRecordedException() const { return threadContext->GetRecordedException() != nullptr; }
        Js::JavascriptExceptionObject * GetAndClearRecordedException(bool *considerPassingToDebugger = nullptr);
        void RecordException(Js::JavascriptExceptionObject * exceptionObject, bool propagateToDebugger = false);
        __declspec(noreturn) void RethrowRecordedException(JavascriptExceptionObject::HostWrapperCreateFuncType hostWrapperCreateFunc);

#if ENABLE_NATIVE_CODEGEN
        BOOL IsNativeAddress(void * codeAddr);
#endif

        uint SaveSourceCopy(Utf8SourceInfo* sourceInfo, int cchLength, bool isCesu8);
        bool SaveSourceCopy(Utf8SourceInfo* const sourceInfo, int cchLength, bool isCesu8, uint * index);

        uint SaveSourceNoCopy(Utf8SourceInfo* sourceInfo, int cchLength, bool isCesu8);

        void CloneSources(ScriptContext* sourceContext);
        Utf8SourceInfo* GetSource(uint sourceIndex);

        uint SourceCount() const { return (uint)sourceList->Count(); }
        void CleanSourceList() { CleanSourceListInternal(false); }
        SourceList* GetSourceList() const { return sourceList; }
        bool IsItemValidInSourceList(int index);

        template <typename TFunction>
        void MapScript(TFunction mapper)
        {
            this->sourceList->Map([mapper] (int, RecyclerWeakReference<Utf8SourceInfo>* sourceInfoWeakReference)
            {
                Utf8SourceInfo* strongRef = sourceInfoWeakReference->Get();

                if (strongRef)
                {
                    mapper(strongRef);
                }
            });
        }

#ifdef CHECK_STACKWALK_EXCEPTION
        void SetIgnoreStackWalkException() {threadContext->GetScriptEntryExit()->ignoreStackWalkException = true; }
#endif

        // For debugging scenarios where execution will go to debugging manager and come back to engine again, enforce the current EER to have
        // 'hasCaller' property set, which will enable the stack walking across frames.
        // Do not call this directly, look for ENFORCE_ENTRYEXITRECORD_HASCALLER macro.
        void EnforceEERHasCaller() { threadContext->GetScriptEntryExit()->hasCaller = true; }

        void SetRaiseMessageToDebuggerFunction(RaiseMessageToDebuggerFunctionType function)
        {
            raiseMessageToDebuggerFunctionType = function;
        }

        void RaiseMessageToDebugger(DEBUG_EVENT_INFO_TYPE messageType, LPCWSTR message, LPCWSTR url)
        {
            if (raiseMessageToDebuggerFunctionType != nullptr)
            {
                raiseMessageToDebuggerFunctionType(this, messageType, message, url);
            }
        }

        void SetTransitionToDebugModeIfFirstSourceFn(TransitionToDebugModeIfFirstSourceFn function)
        {
            transitionToDebugModeIfFirstSourceFn = function;
        }

        void TransitionToDebugModeIfFirstSource(Utf8SourceInfo *sourceInfo)
        {
            if (transitionToDebugModeIfFirstSourceFn != nullptr)
            {
                transitionToDebugModeIfFirstSourceFn(this, sourceInfo);
            }
        }

        void AddSourceSize(size_t sourceSize)
        {
            this->sourceSize += sourceSize;
            this->threadContext->AddSourceSize(sourceSize);
        }

        size_t GetSourceSize()
        {
            return this->sourceSize;
        }

        BOOL SetDeferredBody(BOOL set)
        {
            bool old = this->deferredBody;
            this->deferredBody = !!set;
            return old;
        }

        BOOL GetDeferredBody(void) const
        {
            return this->deferredBody;
        }

    public:
        void FreeFunctionEntryPoint(Js::JavascriptMethod method);

    private:
        uint CloneSource(Utf8SourceInfo* info);
    public:
        void RegisterProtoInlineCache(InlineCache *pCache, PropertyId propId);
        void InvalidateProtoCaches(const PropertyId propertyId);
        void InvalidateAllProtoCaches();
        void RegisterStoreFieldInlineCache(InlineCache *pCache, PropertyId propId);
        void InvalidateStoreFieldCaches(const PropertyId propertyId);
        void InvalidateAllStoreFieldCaches();
        void RegisterIsInstInlineCache(Js::IsInstInlineCache * cache, Js::Var function);
#if DBG
        bool IsIsInstInlineCacheRegistered(Js::IsInstInlineCache * cache, Js::Var function);
#endif
        void ClearInlineCaches();
        void ClearIsInstInlineCaches();
        void ClearForInCaches();
#ifdef PERSISTENT_INLINE_CACHES
        void ClearInlineCachesWithDeadWeakRefs();
#endif
        void ClearScriptContextCaches();
#if ENABLE_NATIVE_CODEGEN
        void RegisterConstructorCache(Js::PropertyId propertyId, Js::ConstructorCache* cache);
#endif

    public:
        void RegisterPrototypeChainEnsuredToHaveOnlyWritableDataPropertiesScriptContext();
    private:
        void DoRegisterPrototypeChainEnsuredToHaveOnlyWritableDataPropertiesScriptContext();
    public:
        void ClearPrototypeChainEnsuredToHaveOnlyWritableDataPropertiesCaches();

    public:
        JavascriptString * GetLastNumberToStringRadix10(double value);
        void SetLastNumberToStringRadix10(double value, JavascriptString * str);
        bool GetLastUtcTimeFromStr(JavascriptString * str, double& dbl);
        void SetLastUtcTimeFromStr(JavascriptString * str, double value);
        bool IsNoContextSourceContextInfo(SourceContextInfo *sourceContextInfo) const
        {
            return sourceContextInfo == cache->noContextSourceContextInfo;
        }

        BOOL IsProfiling()
        {
#ifdef ENABLE_SCRIPT_PROFILING
            return (m_pProfileCallback != nullptr);
#else
            return FALSE;
#endif
        }

        BOOL IsInProfileCallback()
        {
#ifdef ENABLE_SCRIPT_PROFILING
            return m_inProfileCallback;
#else
            return FALSE;
#endif
        }

#if DBG
        SourceContextInfo const * GetNoContextSourceContextInfo() const { return cache->noContextSourceContextInfo; }

#ifdef ENABLE_SCRIPT_PROFILING
        int GetProfileSession()
        {
            AssertMsg(m_pProfileCallback != nullptr, "Asking for profile session when we aren't in one.");
            return m_iProfileSession;
        }

        void StartNewProfileSession()
        {
            AssertMsg(m_pProfileCallback != nullptr, "New Session when the profiler isn't set to any callback.");
            m_iProfileSession++;
        }

        void StopProfileSession()
        {
            AssertMsg(m_pProfileCallback == nullptr, "How to stop when there is still the callback out there");
        }
#endif // ENABLE_SCRIPT_PROFILING

        bool hadProfiled;
        bool HadProfiled() const { return hadProfiled; }
#endif

        SRCINFO *AddHostSrcInfo(SRCINFO const *pSrcInfo);

        inline void CoreSetProfileEventMask(DWORD dwEventMask);
        typedef HRESULT (*RegisterExternalLibraryType)(Js::ScriptContext *pScriptContext);
#ifdef ENABLE_SCRIPT_PROFILING
        HRESULT RegisterProfileProbe(IActiveScriptProfilerCallback *pProfileCallback, DWORD dwEventMask, DWORD dwContext, RegisterExternalLibraryType RegisterExternalLibrary, JavascriptMethod dispatchInvoke);
#endif
        HRESULT SetProfileEventMask(DWORD dwEventMask);
        HRESULT DeRegisterProfileProbe(HRESULT hrReason, JavascriptMethod dispatchInvoke);

        HRESULT RegisterScript(Js::FunctionProxy *pFunctionBody, BOOL fRegisterScript = TRUE);

        // Register static and dynamic scripts
        HRESULT RegisterAllScripts();

        // Iterate through utf8sourceinfo and clear debug document if they are there.
        void EnsureClearDebugDocument();

        // To be called directly only when the thread context is shutting down
        void ShutdownClearSourceLists();

        HRESULT RegisterLibraryFunction(const char16 *pwszObjectName, const char16 *pwszFunctionName, Js::PropertyId functionPropertyId, JavascriptMethod entryPoint);

        HRESULT RegisterBuiltinFunctions(RegisterExternalLibraryType RegisterExternalLibrary);
        void RegisterDebugThunk(bool calledDuringAttach = true);
        void UnRegisterDebugThunk();

        void UpdateRecyclerFunctionEntryPointsForDebugger();
        void SetFunctionInRecyclerToProfileMode(bool enumerateNonUserFunctionsOnly = false);
#ifdef ENABLE_SCRIPT_PROFILING
        static void SetEntryPointToProfileThunk(JavascriptFunction* function);
        static void RestoreEntryPointFromProfileThunk(JavascriptFunction* function);
#endif

        static void RecyclerEnumClassEnumeratorCallback(void *address, size_t size);
        static void RecyclerFunctionCallbackForDebugger(void *address, size_t size);

        static ushort ProcessNameAndGetLength(Js::StringBuilder<ArenaAllocator>* nameBuffer, const WCHAR* name);

#ifdef ASMJS_PLAT
        void TransitionEnvironmentForDebugger(ScriptFunction * scriptFunction);
#endif

#if ENABLE_NATIVE_CODEGEN
        HRESULT RecreateNativeCodeGenerator();
#endif

        HRESULT OnDebuggerAttached();
        HRESULT OnDebuggerDetached();
        HRESULT OnDebuggerAttachedDetached(bool attach);
        void InitializeDebugging();
        bool IsForceNoNative();
        bool IsEnumeratingRecyclerObjects() const { return isEnumeratingRecyclerObjects; }

    private:
        class AutoEnumeratingRecyclerObjects
        {
        public:
            AutoEnumeratingRecyclerObjects(ScriptContext* scriptContext):
                m_scriptContext(scriptContext)
            {
                Assert(!m_scriptContext->IsEnumeratingRecyclerObjects());
                m_scriptContext->isEnumeratingRecyclerObjects = true;
            }

            ~AutoEnumeratingRecyclerObjects()
            {
                Assert(m_scriptContext->IsEnumeratingRecyclerObjects());
                m_scriptContext->isEnumeratingRecyclerObjects = false;
            }

        private:
            ScriptContext* m_scriptContext;
        };

#ifdef EDIT_AND_CONTINUE
    private:
        ScriptEditQuery* activeScriptEditQuery;

        void BeginScriptEditEnumFunctions(ScriptEditQuery* scriptEditQuery) { Assert(!activeScriptEditQuery); activeScriptEditQuery = scriptEditQuery; }
        void EndScriptEditEnumFunctions() { Assert(activeScriptEditQuery); activeScriptEditQuery = nullptr; }
    public:
        ScriptEditQuery* GetActiveScriptEditQuery() const { return activeScriptEditQuery; }

        class AutoScriptEditEnumFunctions
        {
        public:
            AutoScriptEditEnumFunctions(ScriptContext* scriptContext, ScriptEditQuery* scriptEditQuery) : m_scriptContext(scriptContext)
            {
                scriptContext->BeginScriptEditEnumFunctions(scriptEditQuery);
            }
            ~AutoScriptEditEnumFunctions() { m_scriptContext->EndScriptEditEnumFunctions(); }
        private:
            ScriptContext* m_scriptContext;
        };
#endif

    private:
        typedef JsUtil::BaseDictionary<JavascriptMethod, Js::PropertyId, ArenaAllocator, PrimeSizePolicy> BuiltinFunctionIdDictionary;
        BuiltinFunctionIdDictionary *m_pBuiltinFunctionIdMap;
        Js::PropertyId GetFunctionNumber(JavascriptMethod entryPoint);

        static const char16* CopyString(const char16* str, size_t charCount, ArenaAllocator* alloc);
        static charcount_t AppendWithEscapeCharacters(Js::StringBuilder<ArenaAllocator>* stringBuilder, const WCHAR* sourceString, charcount_t sourceStringLen, WCHAR escapeChar, WCHAR charToEscape);

    public:
#if DYNAMIC_INTERPRETER_THUNK
        JavascriptMethod GetNextDynamicAsmJsInterpreterThunk(PVOID* ppDynamicInterpreterThunk);
        JavascriptMethod GetNextDynamicInterpreterThunk(PVOID* ppDynamicInterpreterThunk);
#if DBG
        BOOL IsDynamicInterpreterThunk(JavascriptMethod address);
#endif
        void ReleaseDynamicInterpreterThunk(BYTE* address, bool addtoFreeList);
        void ReleaseDynamicAsmJsInterpreterThunk(BYTE* address, bool addtoFreeList);
#endif

        static Var DebugProfileProbeThunk(RecyclableObject* function, CallInfo callInfo, ...);
        static JavascriptMethod ProfileModeDeferredParse(ScriptFunction **function);
        static Var ProfileModeDeferredParsingThunk(RecyclableObject* function, CallInfo callInfo, ...);

        // Thunks for deferred deserialization of function bodies from the byte code cache
        static JavascriptMethod ProfileModeDeferredDeserialize(ScriptFunction* function);
        static Var ProfileModeDeferredDeserializeThunk(RecyclableObject* function, CallInfo callInfo, ...);

#ifdef ENABLE_SCRIPT_PROFILING
        void SetProfileMode(BOOL fSet);
        static JavascriptMethod GetProfileModeThunk(JavascriptMethod entryPoint);
        static Var ProfileModeThunk_DebugModeWrapper(JavascriptFunction* function, ScriptContext* scriptContext, JavascriptMethod entryPoint, Arguments& args);
        BOOL GetProfileInfo(
            JavascriptFunction* function,
            PROFILER_TOKEN &scriptId,
            PROFILER_TOKEN &functionId);

        HRESULT OnScriptCompiled(PROFILER_TOKEN scriptId, PROFILER_SCRIPT_TYPE type, IUnknown *pIDebugDocumentContext);
        HRESULT OnFunctionCompiled(
            PROFILER_TOKEN functionId,
            PROFILER_TOKEN scriptId,
            const WCHAR *pwszFunctionName,
            const WCHAR *pwszFunctionNameHint,
            IUnknown *pIDebugDocumentContext);
        HRESULT OnFunctionEnter(PROFILER_TOKEN scriptId, PROFILER_TOKEN functionId);
        HRESULT OnFunctionExit(PROFILER_TOKEN scriptId, PROFILER_TOKEN functionId);

        static HRESULT FunctionExitSenderThunk(PROFILER_TOKEN functionId, PROFILER_TOKEN scriptId, ScriptContext *pScriptContext);
        static HRESULT FunctionExitByNameSenderThunk(const char16 *pwszFunctionName, ScriptContext *pScriptContext);
#endif // ENABLE_SCRIPT_PROFILING

        bool SetDispatchProfile(bool fSet, JavascriptMethod dispatchInvoke);
        HRESULT OnDispatchFunctionEnter(const WCHAR *pwszFunctionName);
        HRESULT OnDispatchFunctionExit(const WCHAR *pwszFunctionName);

        void OnStartupComplete();
        void SaveStartupProfileAndRelease(bool isSaveOnClose = false);

#if ENABLE_PROFILE_INFO
        void AddDynamicProfileInfo(FunctionBody * functionBody, WriteBarrierPtr<DynamicProfileInfo>* dynamicProfileInfo);
#endif
#if DBG || defined(RUNTIME_DATA_COLLECTION)
        uint allocId;
#endif

#ifdef PROFILE_EXEC
        void DisableProfiler();
        void SetRecyclerProfiler();
        void SetProfilerFromScriptContext(ScriptContext * scriptContext);
        void ProfileBegin(Js::Phase);
        void ProfileEnd(Js::Phase);
        void ProfileSuspend(Js::Phase, Js::Profiler::SuspendRecord * suspendRecord);
        void ProfileResume(Js::Profiler::SuspendRecord * suspendRecord);
        void ProfilePrint();
        bool IsProfilerCreated() const { return isProfilerCreated; }
#endif

#ifdef PROFILE_MEM
        void DisableProfileMemoryDumpOnDelete() { profileMemoryDump = false; }
#endif

#ifdef PROFILE_STRINGS
        StringProfiler * GetStringProfiler(); // May be null if string profiling not enabled
#endif

    public:
        virtual intptr_t GetNullAddr() const override;
        virtual intptr_t GetUndefinedAddr() const override;
        virtual intptr_t GetTrueAddr() const override;
        virtual intptr_t GetFalseAddr() const override;
        virtual intptr_t GetUndeclBlockVarAddr() const override;
        virtual intptr_t GetEmptyStringAddr() const override;
        virtual intptr_t GetNegativeZeroAddr() const override;
        virtual intptr_t GetNumberTypeStaticAddr() const override;
        virtual intptr_t GetStringTypeStaticAddr() const override;
        virtual intptr_t GetObjectTypeAddr() const override;
        virtual intptr_t GetObjectHeaderInlinedTypeAddr() const override;
        virtual intptr_t GetRegexTypeAddr() const override;
        virtual intptr_t GetArrayTypeAddr() const override;
        virtual intptr_t GetNativeIntArrayTypeAddr() const override;
        virtual intptr_t GetNativeFloatArrayTypeAddr() const override;
        virtual intptr_t GetArrayConstructorAddr() const override;
        virtual intptr_t GetCharStringCacheAddr() const override;
        virtual intptr_t GetSideEffectsAddr() const override;
        virtual intptr_t GetArraySetElementFastPathVtableAddr() const override;
        virtual intptr_t GetIntArraySetElementFastPathVtableAddr() const override;
        virtual intptr_t GetFloatArraySetElementFastPathVtableAddr() const override;
        virtual intptr_t GetLibraryAddr() const override;
        virtual intptr_t GetGlobalObjectAddr() const override;
        virtual intptr_t GetGlobalObjectThisAddr() const override;
        virtual intptr_t GetNumberAllocatorAddr() const override;
        virtual intptr_t GetRecyclerAddr() const override;
        virtual bool GetRecyclerAllowNativeCodeBumpAllocation() const override;
        virtual bool IsSIMDEnabled() const override;
        virtual bool IsPRNGSeeded() const override;
        virtual intptr_t GetBuiltinFunctionsBaseAddr() const override;

#if ENABLE_NATIVE_CODEGEN
        virtual void AddToDOMFastPathHelperMap(intptr_t funcInfoAddr, IR::JnHelperMethod helper) override;
        virtual IR::JnHelperMethod GetDOMFastPathHelper(intptr_t funcInfoAddr) override;
#endif

        virtual intptr_t GetAddr() const override;

        virtual intptr_t GetVTableAddress(VTableValue vtableType) const override;

        virtual bool IsRecyclerVerifyEnabled() const override;
        virtual uint GetRecyclerVerifyPad() const override;
 
        virtual Js::Var* GetModuleExportSlotArrayAddress(uint moduleIndex, uint slotIndex) override;

        Js::SourceTextModuleRecord* GetModuleRecord(uint moduleId) const
        {
            return javascriptLibrary->GetModuleRecord(moduleId);
        }

        void SetBuiltInLibraryFunction(JavascriptMethod entryPoint, JavascriptFunction* function);
        JavascriptFunction* GetBuiltInLibraryFunction(JavascriptMethod entryPoint);

    private:
        BuiltInLibraryFunctionMap* builtInLibraryFunctions;

#if ENABLE_NATIVE_CODEGEN
        JITDOMFastPathHelperMap * m_domFastPathHelperMap;
#endif

#ifdef RECYCLER_PERF_COUNTERS
        size_t bindReferenceCount;
#endif

        ScriptContext * nextPendingClose;
    public:
        void SetNextPendingClose(ScriptContext * nextPendingClose);
        inline ScriptContext * GetNextPendingClose() const { return nextPendingClose; }

#ifdef ENABLE_MUTATION_BREAKPOINT
        // Keep track of all breakpoints in order to properly clean up on debugger detach
        bool HasMutationBreakpoints();
        void InsertMutationBreakpoint(Js::MutationBreakpoint *mutationBreakpoint);
#endif
    };

    class AutoDynamicCodeReference
    {
    public:
        AutoDynamicCodeReference(ScriptContext* scriptContext):
          m_scriptContext(scriptContext)
          {
              scriptContext->GetLibrary()->BeginDynamicFunctionReferences();
          }

          ~AutoDynamicCodeReference()
          {
              m_scriptContext->GetLibrary()->EndDynamicFunctionReferences();
          }

    private:
        ScriptContext* m_scriptContext;
    };

    template <typename TCacheType>
    void ScriptContext::CleanDynamicFunctionCache(TCacheType* cacheType)
    {
        // Remove eval map functions that haven't been recently used
        // TODO: Metric based on allocation size too? So don't clean if there hasn't been much allocated?

        cacheType->Clean([this](const typename TCacheType::KeyType& key, typename TCacheType::ValueType value) {
#ifdef ENABLE_DEBUG_CONFIG_OPTIONS
            if (CONFIG_FLAG(DumpEvalStringOnRemoval))
            {
                Output::Print(_u("EvalMap: Removing Dynamic Function String from dynamic function cache: %s\n"), key.str.GetBuffer()); Output::Flush();
            }
#endif
        });
    }

    template <class TDelegate>
    void ScriptContext::MapFunction(TDelegate mapper)
    {
        if (this->sourceList)
        {
            this->sourceList->Map([&mapper](int, RecyclerWeakReference<Js::Utf8SourceInfo>* sourceInfo)
            {
                Utf8SourceInfo* sourceInfoStrongRef = sourceInfo->Get();
                if (sourceInfoStrongRef)
                {
                    sourceInfoStrongRef->MapFunction(mapper);
                }
            });
        }
    }

    template <class TDelegate>
    FunctionBody* ScriptContext::FindFunction(TDelegate predicate)
    {
        FunctionBody* functionBody = nullptr;

        this->sourceList->MapUntil([&functionBody, &predicate](int, RecyclerWeakReference<Js::Utf8SourceInfo>* sourceInfo) -> bool
        {
            Utf8SourceInfo* sourceInfoStrongRef = sourceInfo->Get();
            if (sourceInfoStrongRef)
            {
                functionBody = sourceInfoStrongRef->FindFunction(predicate);
                if (functionBody)
                {
                    return true;
                }
            }

            return false;
        });

        return functionBody;
    }
}

#define BEGIN_TEMP_ALLOCATOR(allocator, scriptContext, name) \
    Js::TempArenaAllocatorObject *temp##allocator = scriptContext->GetTemporaryAllocator(name); \
    ArenaAllocator * allocator = temp##allocator->GetAllocator();

#define END_TEMP_ALLOCATOR(allocator, scriptContext) \
    scriptContext->ReleaseTemporaryAllocator(temp##allocator);

#define DECLARE_TEMP_ALLOCATOR(allocator) \
    Js::TempArenaAllocatorObject *temp##allocator = nullptr; \
    ArenaAllocator * allocator = nullptr;

#define ACQUIRE_TEMP_ALLOCATOR(allocator, scriptContext, name) \
    temp##allocator = scriptContext->GetTemporaryAllocator(name); \
    allocator = temp##allocator->GetAllocator();

#define RELEASE_TEMP_ALLOCATOR(allocator, scriptContext) \
    if (temp##allocator) \
    scriptContext->ReleaseTemporaryAllocator(temp##allocator);

#define DECLARE_TEMP_GUEST_ALLOCATOR(allocator) \
    Js::TempGuestArenaAllocatorObject *tempGuest##allocator = nullptr; \
    ArenaAllocator * allocator = nullptr;

#define ACQUIRE_TEMP_GUEST_ALLOCATOR(allocator, scriptContext, name) \
    tempGuest##allocator = scriptContext->GetTemporaryGuestAllocator(name); \
    allocator = tempGuest##allocator->GetAllocator();

#define RELEASE_TEMP_GUEST_ALLOCATOR(allocator, scriptContext) \
    if (tempGuest##allocator) \
    scriptContext->ReleaseTemporaryGuestAllocator(tempGuest##allocator);