// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

// ==++==
// 

// 
//

//
// ==--==

#include "stdafx.h"

#include "mscoree.h"
#include "clrinternal.h"
#include "hostimpl.h"
#include "predeftlsslot.h"
#include "unsafe.h"

// to avoid to include clrhost.h in this file
#ifdef FAILPOINTS_ENABLED
extern int RFS_HashStack();
#endif

static DWORD TlsIndex = TLS_OUT_OF_INDEXES;
static PTLS_CALLBACK_FUNCTION Callbacks[MAX_PREDEFINED_TLS_SLOT];

#ifdef SELF_NO_HOST
HANDLE (*g_fnGetExecutableHeapHandle)();
#endif

extern LPVOID* (*__ClrFlsGetBlock)();

//
// FLS getter to avoid unnecessary indirection via execution engine.
//
LPVOID* ClrFlsGetBlockDirect()
{
    return (LPVOID*)UnsafeTlsGetValue(TlsIndex);
}

//
// utility functions for tls functionality
//
static void **CheckThreadState(DWORD slot, BOOL force = TRUE)
{
    // Treat as a runtime assertion, since the invariant spans many DLLs.
    _ASSERTE(slot < MAX_PREDEFINED_TLS_SLOT);

    // Ensure we have a TLS Index
    if (TlsIndex == TLS_OUT_OF_INDEXES)
    {
        DWORD tmp = UnsafeTlsAlloc();

        if (InterlockedCompareExchange((LONG*)&TlsIndex, tmp, TLS_OUT_OF_INDEXES) != (LONG) TLS_OUT_OF_INDEXES)
        {
            // We lost the race with another thread.
            UnsafeTlsFree(tmp);
        }

        // Switch to faster TLS getter now that the TLS slot is initialized
        __ClrFlsGetBlock = ClrFlsGetBlockDirect;
    }

    _ASSERTE(TlsIndex != TLS_OUT_OF_INDEXES);

    void **pTlsData = (void **)TlsGetValue(TlsIndex);

    if (pTlsData == 0 && force) {

        // !!! Contract uses our TLS support.  Contract may be used before our host support is set up.
        // !!! To better support contract, we call into OS for memory allocation.
        pTlsData = (void**) ::HeapAlloc(GetProcessHeap(),0,MAX_PREDEFINED_TLS_SLOT*sizeof(void*));


        if (pTlsData == NULL)
        {
            // workaround! We don't want exceptions being thrown during ClrInitDebugState. Just return NULL out of TlsSetValue.
            // ClrInitDebugState will do a confirming FlsGet to see if the value stuck.

            // If this is for the stack probe, and we failed to allocate memory for it, we won't
            // put in a guard page.
            if (slot == TlsIdx_ClrDebugState || slot == TlsIdx_StackProbe)
            {
                return NULL;
            }
            RaiseException(STATUS_NO_MEMORY, 0, 0, NULL);
        }
        for (int i=0; i<MAX_PREDEFINED_TLS_SLOT; i++)
            pTlsData[i] = 0;
        UnsafeTlsSetValue(TlsIndex, pTlsData);
    }

    return pTlsData;
} // CheckThreadState

// This function should only be called during process detatch for
// mscoree.dll.
VOID STDMETHODCALLTYPE TLS_FreeMasterSlotIndex()
{
    if (TlsIndex != TLS_OUT_OF_INDEXES)
        if (UnsafeTlsFree(TlsIndex))
            TlsIndex = TLS_OUT_OF_INDEXES;
} // TLS_FreeMasterSlotIndex



HRESULT STDMETHODCALLTYPE UtilExecutionEngine::QueryInterface(REFIID id, void **pInterface) 
{
    if (!pInterface)
        return E_POINTER;

    *pInterface = NULL;

    if (id == IID_IExecutionEngine)
        *pInterface = (IExecutionEngine *)this;
    else if (id == IID_IEEMemoryManager)
        *pInterface = (IEEMemoryManager *)this;
    else if (id == IID_IUnknown)
        *pInterface = (IUnknown *)(IExecutionEngine *)this;
    else
        return E_NOINTERFACE;

    AddRef();
    return S_OK;
} // UtilExecutionEngine::QueryInterface

//
// lifetime of this object is that of the app it lives in so no point in AddRef/Release
//
ULONG STDMETHODCALLTYPE UtilExecutionEngine::AddRef() 
{
    return 1;
}

ULONG STDMETHODCALLTYPE UtilExecutionEngine::Release() 
{
    return 1;
}

VOID  STDMETHODCALLTYPE UtilExecutionEngine::TLS_AssociateCallback(DWORD slot, PTLS_CALLBACK_FUNCTION callback) 
{
    CheckThreadState(slot);

    // They can toggle between a callback and no callback.  But anything else looks like
    // confusion on their part.
    //
    // (TlsIdx_ClrDebugState associates its callback from utilcode.lib - which can be replicated. But
    // all the callbacks are equally good.)
    _ASSERTE(slot == TlsIdx_ClrDebugState || Callbacks[slot] == 0 || Callbacks[slot] == callback || callback == 0);
    Callbacks[slot] = callback;
}

LPVOID* STDMETHODCALLTYPE UtilExecutionEngine::TLS_GetDataBlock() 
{
    if (TlsIndex == TLS_OUT_OF_INDEXES)
        return NULL;

    return (LPVOID *)UnsafeTlsGetValue(TlsIndex);
}

LPVOID STDMETHODCALLTYPE UtilExecutionEngine::TLS_GetValue(DWORD slot) 
{
    void **pTlsData = CheckThreadState(slot, FALSE);
    if (pTlsData)
        return pTlsData[slot];
    else
        return NULL;
}

BOOL STDMETHODCALLTYPE UtilExecutionEngine::TLS_CheckValue(DWORD slot, LPVOID * pValue) 
{
    void **pTlsData = CheckThreadState(slot, FALSE);
    if (pTlsData)
    {
        *pValue = pTlsData[slot];
        return TRUE;
    }
    return FALSE;
}

VOID STDMETHODCALLTYPE UtilExecutionEngine::TLS_SetValue(DWORD slot, LPVOID pData) 
{
    void **pTlsData = CheckThreadState(slot);
    if (pTlsData)  // Yes, CheckThreadState(slot, TRUE) can return NULL now.
    {
        pTlsData[slot] = pData;
    }
}

VOID STDMETHODCALLTYPE UtilExecutionEngine::TLS_ThreadDetaching() 
{
    void **pTlsData = CheckThreadState(0, FALSE);
    if (pTlsData)
    {
        for (int i=0; i<MAX_PREDEFINED_TLS_SLOT; i++)
        {
            // If we have some data and a callback, issue it.
            if (Callbacks[i] != 0 && pTlsData[i] != 0)
                (*Callbacks[i])(pTlsData[i]);
        }
        ::HeapFree (GetProcessHeap(),0,pTlsData);

    }
}

CRITSEC_COOKIE STDMETHODCALLTYPE UtilExecutionEngine::CreateLock(LPCSTR szTag, LPCSTR level, CrstFlags flags) 
{
    CRITICAL_SECTION *cs = (CRITICAL_SECTION*)malloc(sizeof(CRITICAL_SECTION));
    UnsafeInitializeCriticalSection(cs);
    return (CRITSEC_COOKIE)cs; 
}

void STDMETHODCALLTYPE UtilExecutionEngine::DestroyLock(CRITSEC_COOKIE lock) 
{
    _ASSERTE(lock);
    UnsafeDeleteCriticalSection((CRITICAL_SECTION*)lock);
    free(lock);
}

void STDMETHODCALLTYPE UtilExecutionEngine::AcquireLock(CRITSEC_COOKIE lock) 
{
    _ASSERTE(lock);
    UnsafeEnterCriticalSection((CRITICAL_SECTION*)lock);
}

void STDMETHODCALLTYPE UtilExecutionEngine::ReleaseLock(CRITSEC_COOKIE lock) 
{
    _ASSERTE(lock);
    UnsafeLeaveCriticalSection((CRITICAL_SECTION*)lock);
}

EVENT_COOKIE STDMETHODCALLTYPE UtilExecutionEngine::CreateAutoEvent(BOOL bInitialState) 
{
    HANDLE handle = UnsafeCreateEvent(NULL, FALSE, bInitialState, NULL);
    _ASSERTE(handle);
    return (EVENT_COOKIE)handle;
}

EVENT_COOKIE STDMETHODCALLTYPE UtilExecutionEngine::CreateManualEvent(BOOL bInitialState) 
{
    HANDLE handle = UnsafeCreateEvent(NULL, TRUE, bInitialState, NULL);
    _ASSERTE(handle);
    return (EVENT_COOKIE)handle;
}

void STDMETHODCALLTYPE UtilExecutionEngine::CloseEvent(EVENT_COOKIE event) 
{
    _ASSERTE(event);
    CloseHandle((HANDLE)event);
}

BOOL STDMETHODCALLTYPE UtilExecutionEngine::ClrSetEvent(EVENT_COOKIE event) 
{
    _ASSERTE(event);
    return UnsafeSetEvent((HANDLE)event);
}

BOOL STDMETHODCALLTYPE UtilExecutionEngine::ClrResetEvent(EVENT_COOKIE event) 
{
    _ASSERTE(event);
    return UnsafeResetEvent((HANDLE)event);
}

DWORD STDMETHODCALLTYPE UtilExecutionEngine::WaitForEvent(EVENT_COOKIE event, DWORD dwMilliseconds, BOOL bAlertable) 
{
    _ASSERTE(event);
    return WaitForSingleObjectEx((HANDLE)event, dwMilliseconds, bAlertable);
}

DWORD STDMETHODCALLTYPE UtilExecutionEngine::WaitForSingleObject(HANDLE handle, DWORD dwMilliseconds) 
{
    _ASSERTE(handle);
    return WaitForSingleObjectEx(handle, dwMilliseconds, FALSE);
}

SEMAPHORE_COOKIE STDMETHODCALLTYPE UtilExecutionEngine::ClrCreateSemaphore(DWORD dwInitial, DWORD dwMax) 
{
    HANDLE handle = UnsafeCreateSemaphore(NULL, (LONG)dwInitial, (LONG)dwMax, NULL);
    _ASSERTE(handle);
    return (SEMAPHORE_COOKIE)handle;
}

void STDMETHODCALLTYPE UtilExecutionEngine::ClrCloseSemaphore(SEMAPHORE_COOKIE semaphore) 
{
    _ASSERTE(semaphore);
    CloseHandle((HANDLE)semaphore);
}

DWORD STDMETHODCALLTYPE UtilExecutionEngine::ClrWaitForSemaphore(SEMAPHORE_COOKIE semaphore, DWORD dwMilliseconds, BOOL bAlertable) 
{
    _ASSERTE(semaphore);
    return WaitForSingleObjectEx((HANDLE)semaphore, dwMilliseconds, bAlertable);
}

BOOL STDMETHODCALLTYPE UtilExecutionEngine::ClrReleaseSemaphore(SEMAPHORE_COOKIE semaphore, LONG lReleaseCount, LONG *lpPreviousCount) 
{
    _ASSERTE(semaphore);
    return UnsafeReleaseSemaphore((HANDLE)semaphore, lReleaseCount, lpPreviousCount);
}

MUTEX_COOKIE STDMETHODCALLTYPE UtilExecutionEngine::ClrCreateMutex(LPSECURITY_ATTRIBUTES lpMutexAttributes,
                                                                BOOL bInitialOwner,
                                                                LPCTSTR lpName)
{
    return (MUTEX_COOKIE)WszCreateMutex(lpMutexAttributes,bInitialOwner,lpName);
}

void STDMETHODCALLTYPE UtilExecutionEngine::ClrCloseMutex(MUTEX_COOKIE mutex)
{
    _ASSERTE(mutex);
    CloseHandle((HANDLE)mutex);
}

BOOL STDMETHODCALLTYPE UtilExecutionEngine::ClrReleaseMutex(MUTEX_COOKIE mutex)
{
    _ASSERTE(mutex);
    return ReleaseMutex((HANDLE)mutex);
}

DWORD STDMETHODCALLTYPE UtilExecutionEngine::ClrWaitForMutex(MUTEX_COOKIE mutex,
                                                          DWORD dwMilliseconds,
                                                          BOOL bAlertable)
{
    _ASSERTE(mutex);
    return WaitForSingleObjectEx ((HANDLE)mutex, dwMilliseconds, bAlertable);
}

DWORD STDMETHODCALLTYPE UtilExecutionEngine::ClrSleepEx(DWORD dwMilliseconds, BOOL bAlertable)
{
    return SleepEx (dwMilliseconds, bAlertable);    
}

BOOL STDMETHODCALLTYPE UtilExecutionEngine::ClrAllocationDisallowed() 
{
    return FALSE;    
}

LPVOID STDMETHODCALLTYPE UtilExecutionEngine::ClrVirtualAlloc(LPVOID lpAddress, SIZE_T dwSize, DWORD flAllocationType, DWORD flProtect) 
{
#ifdef FAILPOINTS_ENABLED
        if (RFS_HashStack ())
            return NULL;
#endif
    return VirtualAlloc(lpAddress, dwSize, flAllocationType, flProtect);
}

BOOL STDMETHODCALLTYPE UtilExecutionEngine::ClrVirtualFree(LPVOID lpAddress, SIZE_T dwSize, DWORD dwFreeType) 
{
    return VirtualFree(lpAddress, dwSize, dwFreeType);
}

SIZE_T STDMETHODCALLTYPE UtilExecutionEngine::ClrVirtualQuery(LPCVOID lpAddress, PMEMORY_BASIC_INFORMATION lpBuffer, SIZE_T dwLength) 
{
    return VirtualQuery(lpAddress, lpBuffer, dwLength);
}

BOOL STDMETHODCALLTYPE UtilExecutionEngine::ClrVirtualProtect(LPVOID lpAddress, SIZE_T dwSize, DWORD flNewProtect, PDWORD lpflOldProtect) 
{
    return VirtualProtect(lpAddress, dwSize, flNewProtect, lpflOldProtect);
}

HANDLE STDMETHODCALLTYPE UtilExecutionEngine::ClrGetProcessHeap() 
{
    return GetProcessHeap();
}

HANDLE STDMETHODCALLTYPE UtilExecutionEngine::ClrGetProcessExecutableHeap() 
{
#ifndef CROSSGEN_COMPILE
    _ASSERTE(g_fnGetExecutableHeapHandle);
    return (g_fnGetExecutableHeapHandle != NULL) ? g_fnGetExecutableHeapHandle() : NULL;
#else
    return GetProcessHeap();
#endif
}

HANDLE STDMETHODCALLTYPE UtilExecutionEngine::ClrHeapCreate(DWORD flOptions, SIZE_T dwInitialSize, SIZE_T dwMaximumSize) 
{
#ifdef FEATURE_PAL
    return NULL;
#else
    return HeapCreate(flOptions, dwInitialSize, dwMaximumSize);
#endif
}

BOOL STDMETHODCALLTYPE UtilExecutionEngine::ClrHeapDestroy(HANDLE hHeap) 
{
#ifdef FEATURE_PAL
    return FALSE;
#else
    return HeapDestroy(hHeap);
#endif
}

LPVOID STDMETHODCALLTYPE UtilExecutionEngine::ClrHeapAlloc(HANDLE hHeap, DWORD dwFlags, SIZE_T dwBytes) 
{
#ifdef FAILPOINTS_ENABLED
        if (RFS_HashStack ())
            return NULL;
#endif
    return HeapAlloc(hHeap, dwFlags, dwBytes);
}

BOOL STDMETHODCALLTYPE UtilExecutionEngine::ClrHeapFree(HANDLE hHeap, DWORD dwFlags, LPVOID lpMem) 
{
    return HeapFree(hHeap, dwFlags, lpMem);
}

BOOL STDMETHODCALLTYPE UtilExecutionEngine::ClrHeapValidate(HANDLE hHeap, DWORD dwFlags, LPCVOID lpMem) 
{
#ifdef FEATURE_PAL
    return FALSE;
#else
    return HeapValidate(hHeap, dwFlags, lpMem);
#endif
}


//------------------------------------------------------------------------------
// Helper function to get an exception from outside the exception.  In
//  the CLR, it may be from the Thread object.  Non-CLR users have no thread object,
//  and it will do nothing.

void UtilExecutionEngine::GetLastThrownObjectExceptionFromThread(void **ppvException)
{
    // Declare class so we can declare Exception**
    class Exception;

    // Cast to our real type.
    Exception **ppException = reinterpret_cast<Exception**>(ppvException);

    *ppException = NULL;
} // UtilExecutionEngine::GetLastThrownObjectExceptionFromThread