/*
 * This file is a part of TTMath Bignum Library
 * and is distributed under the (new) BSD licence.
 * Author: Tomasz Sowa <t.sowa@ttmath.org>
 */

/* 
 * Copyright (c) 2006-2009, Tomasz Sowa
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 *  * Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *    
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *    
 *  * Neither the name Tomasz Sowa nor the names of contributors to this
 *    project may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */



#ifndef headerfilettmaththreads
#define headerfilettmaththreads

#include "ttmathtypes.hpp"

#ifdef TTMATH_WIN32_THREADS
#include <windows.h>
#include <cstdio>
#endif

#ifdef TTMATH_POSIX_THREADS
#include <pthread.h>
#endif



/*!
    \file ttmaththreads.h
    \brief Some objects used in multithreads environment
*/


/*
    this is a simple skeleton of a program in multithreads environment:

    #define TTMATH_MULTITHREADS
    #include<ttmath/ttmath.h>
    
    TTMATH_MULTITHREADS_HELPER

    int main()
    {
    [...]
    }

    make sure that macro TTMATH_MULTITHREADS is defined and (somewhere in *.cpp file)
    use TTMATH_MULTITHREADS_HELPER macro (outside of any classes/functions/namespaces scope)
*/


namespace ttmath
{


#ifdef TTMATH_WIN32_THREADS

    /*
        we use win32 threads
    */


    /*!
        in multithreads environment you should use TTMATH_MULTITHREADS_HELPER macro
        somewhere in *.cpp file

        (at the moment in win32 this macro does nothing)
    */
    #define TTMATH_MULTITHREADS_HELPER


    /*!
        objects of this class are used to synchronize
    */
    class ThreadLock
    {
        HANDLE mutex_handle;


        void CreateName(char * buffer) const
        {
            #ifdef _MSC_VER
            #pragma warning (disable : 4996)
            // warning C4996: 'sprintf': This function or variable may be unsafe. Consider using sprintf_s instead.
            #endif

            sprintf(buffer, "TTMATH_LOCK_%ul", (unsigned long)GetCurrentProcessId());

            #ifdef _MSC_VER
            #pragma warning (default : 4996)
            #endif
        }


    public:

        bool Lock()
        {
        char buffer[50];

            CreateName(buffer);
            mutex_handle = CreateMutexA(0, false, buffer);

            if( mutex_handle == 0 )
                return false;

            WaitForSingleObject(mutex_handle, INFINITE);

        return true;
        }


        ThreadLock()
        {
            mutex_handle = 0;
        }


        ~ThreadLock()
        {
            if( mutex_handle != 0 )
            {
                ReleaseMutex(mutex_handle);
                CloseHandle(mutex_handle);
            }
        }
    };

#endif  // #ifdef TTMATH_WIN32_THREADS





#ifdef TTMATH_POSIX_THREADS

    /*
        we use posix threads
    */


    /*!
        in multithreads environment you should use TTMATH_MULTITHREADS_HELPER macro
        somewhere in *.cpp file
        (this macro defines a pthread_mutex_t object used by TTMath library)
    */
    #define TTMATH_MULTITHREADS_HELPER                          \
    namespace ttmath                                            \
    {                                                           \
    pthread_mutex_t ttmath_mutex = PTHREAD_MUTEX_INITIALIZER;   \
    }


    /*!
        ttmath_mutex will be defined by TTMATH_MULTITHREADS_HELPER macro 
    */
    extern pthread_mutex_t ttmath_mutex;


    /*!
        objects of this class are used to synchronize
    */
    class ThreadLock
    {
    public:

        bool Lock()
        {
            if( pthread_mutex_lock(&ttmath_mutex) != 0 )
                return false;

        return true;
        }


        ~ThreadLock()
        {
            pthread_mutex_unlock(&ttmath_mutex);
        }
    };

#endif // #ifdef TTMATH_POSIX_THREADS




#if !defined(TTMATH_POSIX_THREADS) && !defined(TTMATH_WIN32_THREADS)

    /*!
        we don't use win32 and pthreads
    */

    /*!
    */
    #define TTMATH_MULTITHREADS_HELPER


    /*!
        objects of this class are used to synchronize
        actually we don't synchronize, the method Lock() returns always 'false'
    */
    class ThreadLock
    {
    public:

        bool Lock()
        {
            return false;
        }
    };


#endif // #if !defined(TTMATH_POSIX_THREADS) && !defined(TTMATH_WIN32_THREADS)





} // namespace

#endif

