/*
* All or portions of this file Copyright (c) Amazon.com, Inc. or its affiliates or
* its licensors.
*
* For complete copyright and license terms please see the LICENSE at the root of this
* distribution (the "License"). All use of this software is governed by the License,
* or, if provided, by the license below or the license accompanying this file. Do not
* remove or modify any license notices. This file is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
*
*/
// Original file Copyright Crytek GMBH or its affiliates, used under license.

//////////////////////////////////////////////////////////////////////////
// NOTE: INTERNAL HEADER NOT FOR PUBLIC USE
// This header should only be include by SystemThreading.cpp only
// It provides an interface for WinApi intrinsics
// It's only client should be CThreadManager which should manage all thread interaction

#pragma once

#if defined(AZ_RESTRICTED_PLATFORM)
#undef AZ_RESTRICTED_SECTION
#define CRYTHREADUTIL_WIN32_THREAD_H_SECTION_1 1
#define CRYTHREADUTIL_WIN32_THREAD_H_SECTION_2 2
#endif

#if !defined(INCLUDED_FROM_SYSTEM_THREADING_CPP)
#   error "CRYTEK INTERNAL HEADER. ONLY INCLUDE FROM SYSTEMTHRADING.CPP."
#endif
//////////////////////////////////////////////////////////////////////////

#define DEFAULT_THREAD_STACK_SIZE_KB 0

// Returns the last Win32 error, in string format. Returns an empty string if there is no error.
static string GetLastErrorAsString()
{
    // Get the error message, if any.
    DWORD errorMessageID = GetLastError();
    if (errorMessageID == 0)
    {
        return "";
    }

#if defined(AZ_RESTRICTED_PLATFORM)
#define AZ_RESTRICTED_SECTION CRYTHREADUTIL_WIN32_THREAD_H_SECTION_1
    #if defined(AZ_PLATFORM_XENIA)
        #include "Xenia/CryThreadUtil_win32_thread_h_xenia.inl"
    #elif defined(AZ_PLATFORM_PROVO)
        #include "Provo/CryThreadUtil_win32_thread_h_provo.inl"
    #elif defined(AZ_PLATFORM_SALEM)
        #include "Salem/CryThreadUtil_win32_thread_h_salem.inl"
    #endif
#endif
#if defined(AZ_RESTRICTED_SECTION_IMPLEMENTED)
#undef AZ_RESTRICTED_SECTION_IMPLEMENTED
#else
    LPSTR messageBuffer = nullptr;
    size_t size = FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, NULL, errorMessageID, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), messageBuffer, 0, NULL);

    string message(messageBuffer, size);

    // Free the buffer.
    LocalFree(messageBuffer);

    return message;
#endif
}

//////////////////////////////////////////////////////////////////////////
// THREAD CREATION AND MANAGMENT
//////////////////////////////////////////////////////////////////////////
namespace CryThreadUtil
{
    // Define type for platform specific thread handle
    typedef THREAD_HANDLE TThreadHandle;

    struct SThreadCreationDesc
    {
        // Define platform specific thread entry function functor type
        typedef unsigned int(_stdcall * EntryFunc)(void*);

        const char* szThreadName;
        EntryFunc fpEntryFunc;
        void* pArgList;
        uint32 nStackSizeInBytes;
    };

    //////////////////////////////////////////////////////////////////////////
    TThreadHandle CryGetCurrentThreadHandle()
    {
        return GetCurrentThread(); // most likely returns pseudo handle (0xfffffffe)
    }

    //////////////////////////////////////////////////////////////////////////
    // Note: Handle must be closed lated via CryCloseThreadHandle()
    TThreadHandle CryDuplicateThreadHandle(const TThreadHandle& hThreadHandle)
    {
        // NOTES:
        // GetCurrentThread() may return a psydo handle to the current thread
        // to avoid going into the slower kernel mode.
        // Hence the handle is useless when being used from an other thread.
        //  - GetCurrentThread()  -> 0xfffffffe
        //  - GetCurrentProcess() -> 0xffffffff

        HANDLE hRealHandle = 0;
        DuplicateHandle(GetCurrentProcess(), // Source Process Handle.
            hThreadHandle,       // Source Handle to dup.
            GetCurrentProcess(), // Target Process Handle.
            &hRealHandle,        // Target Handle pointer.
            0,                   // Options flag.
            TRUE,                // Inheritable flag
            DUPLICATE_SAME_ACCESS);  // Options

        return (TThreadHandle)hRealHandle;
    }

    //////////////////////////////////////////////////////////////////////////
    void CryCloseThreadHandle(TThreadHandle& hThreadHandle)
    {
        if (hThreadHandle)
        {
            CloseHandle(hThreadHandle);
        }
    }

    //////////////////////////////////////////////////////////////////////////
    threadID CryGetCurrentThreadId()
    {
        return GetCurrentThreadId();
    }

    //////////////////////////////////////////////////////////////////////////
    threadID CryGetThreadId(TThreadHandle hThreadHandle)
    {
        return GetThreadId(hThreadHandle);
    }

    //////////////////////////////////////////////////////////////////////////
    void CrySetThreadName(TThreadHandle pThreadHandle, const char* sThreadName)
    {
        const DWORD MS_VC_EXCEPTION = 0x406D1388;

        struct SThreadNameDesc
        {
            DWORD dwType;           // Must be 0x1000.
            LPCSTR szName;      // Pointer to name (in user addr space).
            DWORD dwThreadID;   // Thread ID (-1=caller thread).
            DWORD dwFlags;      // Reserved for future use, must be zero.
        };

        SThreadNameDesc info;
        info.dwType = 0x1000;
        info.szName = sThreadName;
        info.dwThreadID = GetThreadId(pThreadHandle);
        info.dwFlags = 0;
#pragma warning(push)
#pragma warning(disable : 6312 6322)
        // warning C6312: Possible infinite loop: use of the constant EXCEPTION_CONTINUE_EXECUTION in the exception-filter expression of a try-except
        // warning C6322: empty _except block
        __try
        {
            // Raise exception to set thread name for attached debugger
            RaiseException(MS_VC_EXCEPTION, 0, sizeof(info) / sizeof(DWORD), (ULONG_PTR*)&info);
        }
        __except (GetExceptionCode() == MS_VC_EXCEPTION ? EXCEPTION_CONTINUE_EXECUTION : EXCEPTION_EXECUTE_HANDLER)
        {
        }
#pragma warning(pop)
    }

    //////////////////////////////////////////////////////////////////////////
    void CrySetThreadAffinityMask(TThreadHandle pThreadHandle, DWORD dwAffinityMask)
    {
        SetThreadAffinityMask(pThreadHandle, dwAffinityMask);
    }

    //////////////////////////////////////////////////////////////////////////
    void CrySetThreadPriority(TThreadHandle pThreadHandle, DWORD dwPriority)
    {
        if (!SetThreadPriority(pThreadHandle, dwPriority))
        {
            string errMsg = GetLastErrorAsString();
            CryWarning(VALIDATOR_MODULE_SYSTEM, VALIDATOR_WARNING, "<ThreadInfo> Unable to set thread priority. System Error Msg: \"%s\"", errMsg.c_str());
            return;
        }
    }

    //////////////////////////////////////////////////////////////////////////
    void CrySetThreadPriorityBoost(TThreadHandle pThreadHandle, bool bEnabled)
    {
        SetThreadPriorityBoost(pThreadHandle, !bEnabled);
    }

    //////////////////////////////////////////////////////////////////////////
    bool CryCreateThread(TThreadHandle* pThreadHandle, const SThreadCreationDesc& threadDesc)
    {
        const uint32 nStackSize = threadDesc.nStackSizeInBytes != 0 ? threadDesc.nStackSizeInBytes : DEFAULT_THREAD_STACK_SIZE_KB * 1024;

        // Create thread
        unsigned int threadId = 0;
#if defined(AZ_RESTRICTED_PLATFORM)
#define AZ_RESTRICTED_SECTION CRYTHREADUTIL_WIN32_THREAD_H_SECTION_2
    #if defined(AZ_PLATFORM_XENIA)
        #include "Xenia/CryThreadUtil_win32_thread_h_xenia.inl"
    #elif defined(AZ_PLATFORM_PROVO)
        #include "Provo/CryThreadUtil_win32_thread_h_provo.inl"
    #elif defined(AZ_PLATFORM_SALEM)
        #include "Salem/CryThreadUtil_win32_thread_h_salem.inl"
    #endif
#endif
#if defined(AZ_RESTRICTED_SECTION_IMPLEMENTED)
#undef AZ_RESTRICTED_SECTION_IMPLEMENTED
#else
        *pThreadHandle = (void*)_beginthreadex(NULL, nStackSize, threadDesc.fpEntryFunc, threadDesc.pArgList, CREATE_SUSPENDED, &threadId);
#endif

        if (!(*pThreadHandle))
        {
            string errMsg = GetLastErrorAsString();
            CryWarning(VALIDATOR_MODULE_SYSTEM, VALIDATOR_WARNING, "<ThreadInfo> Unable to create thread \"%s\". System Error Msg: \"%s\"", threadDesc.szThreadName, errMsg.c_str());
            return false;
        }

        // Start thread
        ResumeThread(*pThreadHandle);

        // Print info to log
        CryComment("<ThreadInfo>: New thread \"%s\" | StackSize: %u(KB)", threadDesc.szThreadName, threadDesc.nStackSizeInBytes / 1024);
        return true;
    }

    //////////////////////////////////////////////////////////////////////////
    void CryThreadExitCall()
    {
        // Note on: ExitThread() (from MSDN)
        // ExitThread is the preferred method of exiting a thread in C code.
        // However, in C++ code, the thread is exited before any destructor can be called or any other automatic cleanup can be performed.
        // Therefore, in C++ code, you should return from your thread function.
    }
}

//////////////////////////////////////////////////////////////////////////
// FLOATING POINT EXCEPTIONS
//////////////////////////////////////////////////////////////////////////
namespace CryThreadUtil
{
    ///////////////////////////////////////////////////////////////////////////
    void EnableFloatExceptions(EFPE_Severity eFPESeverity)
    {
#pragma warning( push )
#pragma warning(disable: 4996)

        // Optimization
        // Enable DAZ/FZ
        // Denormals Are Zeros
        // Flush-to-Zero
        _controlfp(_DN_FLUSH, _MCW_DN);
        _mm_setcsr(_mm_getcsr() | _MM_FLUSH_ZERO_ON);

#ifndef _RELEASE
        if (eFPESeverity == eFPE_None)
        {
            // mask all floating exceptions off.
            _controlfp(_MCW_EM, _MCW_EM);
            _mm_setcsr(_mm_getcsr() | _MM_MASK_MASK);
        }
        else
        {
            // Clear pending exceptions
            _fpreset();

            if (eFPESeverity == eFPE_Basic)
            {
                // Enable:
                // - _EM_ZERODIVIDE
                // - _EM_INVALID
                //
                // Disable:
                // - _EM_DENORMAL
                // - _EM_OVERFLOW
                // - _EM_UNDERFLOW
                // - _EM_INEXACT

                _controlfp(_EM_INEXACT | _EM_DENORMAL | _EM_UNDERFLOW | _EM_OVERFLOW, _MCW_EM);
                _mm_setcsr((_mm_getcsr() & ~_MM_MASK_MASK) | (_MM_MASK_DENORM | _MM_MASK_INEXACT | _MM_MASK_UNDERFLOW | _MM_MASK_OVERFLOW));

                //_mm_setcsr(_mm_getcsr() & ~0x280);
            }

            if (eFPESeverity == eFPE_All)
            {
                // Enable:
                // - _EM_ZERODIVIDE
                // - _EM_INVALID
                // - _EM_UNDERFLOW
                // - _EM_OVERFLOW
                //
                // Disable:
                // - _EM_INEXACT
                // - _EM_DENORMAL

                _controlfp(_EM_INEXACT | _EM_DENORMAL, _MCW_EM);
                _mm_setcsr((_mm_getcsr() & ~_MM_MASK_MASK) | (_MM_MASK_INEXACT | _MM_MASK_DENORM));
            }
        }
#endif // _RELEASE

#pragma warning( pop )
}

    //////////////////////////////////////////////////////////////////////////
    void EnableFloatExceptions(threadID nThreadId, EFPE_Severity eFPESeverity)
    {
        if (eFPESeverity >= eFPE_LastEntry)
        {
            CryWarning(VALIDATOR_MODULE_SYSTEM, VALIDATOR_ERROR, "Floating Point Exception (FPE) severity is out of range. (%i)", eFPESeverity);
        }

        // Check if the thread ID matches the current thread
        if (nThreadId == 0 || nThreadId == CryGetCurrentThreadId())
        {
            EnableFloatExceptions(eFPESeverity);
            return;
        }

        HANDLE hThread = OpenThread(THREAD_ALL_ACCESS, true, nThreadId);

        if (hThread == 0)
        {
            CryWarning(VALIDATOR_MODULE_SYSTEM, VALIDATOR_ERROR, "Unable to open thread. %p", hThread);
            return;
        }

        SuspendThread(hThread);

        CONTEXT ctx;
        memset(&ctx, 0, sizeof(ctx));
        ctx.ContextFlags = CONTEXT_ALL;
        if (GetThreadContext(hThread, &ctx) == 0)
        {
            CryWarning(VALIDATOR_MODULE_SYSTEM, VALIDATOR_ERROR, "Unable to get thread context");
            ResumeThread(hThread);
            CloseHandle(hThread);
            return;
        }

#ifdef PLATFORM_64BIT
        //////////////////////////////////////////////////////////////////////////
        // Note:
        // DO NOT USE ctx.FltSave.MxCsr ... SetThreadContext() will copy the value of ctx.MxCsr into it
        //////////////////////////////////////////////////////////////////////////
        DWORD& floatMxCsr = ctx.MxCsr; // Hold FPE Mask and Status for MMX (SSE) floating point registers
        WORD& floatControlWord = ctx.FltSave.ControlWord;   // Hold FPE Mask for floating point registers
        WORD& floatStatuslWord = ctx.FltSave.StatusWord;    // Holds FPE Status for floating point registers
#else
        DWORD& floatMxCsr = *(DWORD*)(&ctx.ExtendedRegisters[24]);  // Hold FPE Mask and Status for MMX (SSE) floating point registers
        DWORD& floatControlWord = ctx.FloatSave.ControlWord;    // Hold FPE Mask for floating point registers
        DWORD& floatStatuslWord = ctx.FloatSave.StatusWord; // Holds FPE Status for floating point registers
#endif

        // Flush-To-Zero Mode
        // Two conditions must be met for FTZ processing to occur:
        // - The FTZ bit (bit 15) in the MXCSR register must be masked (value = 1).
        // - The underflow exception (bit 11) needs to be masked (value = 1).

        // Set flush mode to zero mode
        floatControlWord = (floatControlWord & ~_MCW_DN) | _DN_FLUSH;
        floatMxCsr = (floatMxCsr & ~_MM_FLUSH_ZERO_MASK) | (_MM_FLUSH_ZERO_ON);

#ifndef _RELEASE

        // Reset FPE bits
        floatControlWord = floatControlWord | _MCW_EM;
        floatMxCsr = floatMxCsr | _MM_MASK_MASK;

        // Clear pending exceptions
        floatStatuslWord = floatStatuslWord & ~(_SW_INEXACT | _SW_UNDERFLOW | _SW_OVERFLOW | _SW_ZERODIVIDE | _SW_INVALID | _SW_DENORMAL);
        floatMxCsr = floatMxCsr & ~(_MM_EXCEPT_INEXACT | _MM_EXCEPT_UNDERFLOW | _MM_EXCEPT_OVERFLOW | _MM_EXCEPT_DIV_ZERO | _MM_EXCEPT_INVALID | _MM_EXCEPT_DENORM);

        if (eFPESeverity == eFPE_Basic)
        {
            // Enable:
            // - _EM_ZERODIVIDE
            // - _EM_INVALID
            //
            // Disable:
            // - _EM_DENORMAL
            // - _EM_OVERFLOW
            // - _EM_UNDERFLOW
            // - _EM_INEXACT

            floatControlWord = (floatControlWord & ~_MCW_EM) | (_EM_DENORMAL | _EM_INEXACT | EM_UNDERFLOW | _EM_OVERFLOW);
            floatMxCsr = (floatMxCsr & ~_MM_MASK_MASK) | (_MM_MASK_DENORM | _MM_MASK_INEXACT | _MM_MASK_UNDERFLOW | _MM_MASK_OVERFLOW);
        }

        if (eFPESeverity == eFPE_All)
        {
            // Enable:
            // - _EM_ZERODIVIDE
            // - _EM_INVALID
            // - _EM_UNDERFLOW
            // - _EM_OVERFLOW
            //
            // Disable:
            // - _EM_INEXACT
            // - _EM_DENORMAL

            floatControlWord = (floatControlWord & ~_MCW_EM) | (_EM_INEXACT | _EM_DENORMAL);
            floatMxCsr = (floatMxCsr & ~_MM_MASK_MASK) | (_MM_MASK_INEXACT | _MM_MASK_DENORM);
        }
#endif

        ctx.ContextFlags = CONTEXT_ALL;
        if (SetThreadContext(hThread, &ctx) == 0)
        {
            CryWarning(VALIDATOR_MODULE_SYSTEM, VALIDATOR_ERROR, "Error setting ThreadContext for ThreadID: %u", nThreadId);
            ResumeThread(hThread);
            CloseHandle(hThread);
            return;
        }

        ResumeThread(hThread);
        CloseHandle(hThread);
    }

    //////////////////////////////////////////////////////////////////////////
    uint GetFloatingPointExceptionMask()
    {
        uint nMask = 0;
        _clearfp();
        _controlfp_s(&nMask, 0, 0);
        return nMask;
    }

    //////////////////////////////////////////////////////////////////////////
    void SetFloatingPointExceptionMask(uint nMask)
    {
        uint temp = 0;
        _clearfp();
        const unsigned int kAllowedBits = _MCW_DN | _MCW_EM | _MCW_RC;
        _controlfp_s(&temp, nMask, kAllowedBits);
    }
}