/**

 * Copyright (c) 2016 Tino Reichardt

 * All rights reserved.

 *

 * You can contact the author at:

 * - zstdmt source repository: https://github.com/mcmilk/zstdmt

 *

 * This source code is licensed under both the BSD-style license (found in the

 * LICENSE file in the root directory of this source tree) and the GPLv2 (found

 * in the COPYING file in the root directory of this source tree).

 * You may select, at your option, one of the above-listed licenses.

 */

/**

 * This file will hold wrapper for systems, which do not support pthreads

 */

#include "threading.h"

/* create fake symbol to avoid empty translation unit warning */

int g_ZSTD_threading_useless_symbol;

#if defined(ZSTD_MULTITHREAD) && defined(_WIN32)

/**

 * Windows minimalist Pthread Wrapper

 */

/* ===  Dependencies  === */

#include <process.h>

#include <errno.h>

/* ===  Implementation  === */

typedef struct {

    void* (*start_routine)(void*);

    void* arg;

    int initialized;

    ZSTD_pthread_cond_t initialized_cond;

    ZSTD_pthread_mutex_t initialized_mutex;

} ZSTD_thread_params_t;

static unsigned __stdcall worker(void *arg)

{

    void* (*start_routine)(void*);

    void* thread_arg;

    /* Initialized thread_arg and start_routine and signal main thread that we don't need it

     * to wait any longer.

     */

    {

        ZSTD_thread_params_t*  thread_param = (ZSTD_thread_params_t*)arg;

        thread_arg = thread_param->arg;

        start_routine = thread_param->start_routine;

        /* Signal main thread that we are running and do not depend on its memory anymore */

        ZSTD_pthread_mutex_lock(&thread_param->initialized_mutex);

        thread_param->initialized = 1;

        ZSTD_pthread_cond_signal(&thread_param->initialized_cond);

        ZSTD_pthread_mutex_unlock(&thread_param->initialized_mutex);

    }

    start_routine(thread_arg);

    return 0;

}

int ZSTD_pthread_create(ZSTD_pthread_t* thread, const void* unused,

            void* (*start_routine) (void*), void* arg)

{

    ZSTD_thread_params_t thread_param;

    (void)unused;

    if (thread==NULL) return -1;

    *thread = NULL;

    thread_param.start_routine = start_routine;

    thread_param.arg = arg;

    thread_param.initialized = 0;

    /* Setup thread initialization synchronization */

    if(ZSTD_pthread_cond_init(&thread_param.initialized_cond, NULL)) {

        /* Should never happen on Windows */

        return -1;

    }

    if(ZSTD_pthread_mutex_init(&thread_param.initialized_mutex, NULL)) {

        /* Should never happen on Windows */

        ZSTD_pthread_cond_destroy(&thread_param.initialized_cond);

        return -1;

    }

    /* Spawn thread */

    *thread = (HANDLE)_beginthreadex(NULL, 0, worker, &thread_param, 0, NULL);

    if (*thread==NULL) {

        ZSTD_pthread_mutex_destroy(&thread_param.initialized_mutex);

        ZSTD_pthread_cond_destroy(&thread_param.initialized_cond);

        return errno;

    }

    /* Wait for thread to be initialized */

    ZSTD_pthread_mutex_lock(&thread_param.initialized_mutex);

    while(!thread_param.initialized) {

        ZSTD_pthread_cond_wait(&thread_param.initialized_cond, &thread_param.initialized_mutex);

    }

    ZSTD_pthread_mutex_unlock(&thread_param.initialized_mutex);

    ZSTD_pthread_mutex_destroy(&thread_param.initialized_mutex);

    ZSTD_pthread_cond_destroy(&thread_param.initialized_cond);

    return 0;

}

int ZSTD_pthread_join(ZSTD_pthread_t thread)

{

    DWORD result;

    if (!thread) return 0;

    result = WaitForSingleObject(thread, INFINITE);

    CloseHandle(thread);

    switch (result) {

    case WAIT_OBJECT_0:

        return 0;

    case WAIT_ABANDONED:

        return EINVAL;

    default:

        return GetLastError();

    }

}

#endif   /* ZSTD_MULTITHREAD */

#if defined(ZSTD_MULTITHREAD) && DEBUGLEVEL >= 1 && !defined(_WIN32)

#define ZSTD_DEPS_NEED_MALLOC

#include "zstd_deps.h"

int ZSTD_pthread_mutex_init(ZSTD_pthread_mutex_t* mutex, pthread_mutexattr_t const* attr)

{

    assert(mutex != NULL);

    *mutex = (pthread_mutex_t*)ZSTD_malloc(sizeof(pthread_mutex_t));

    if (!*mutex)

        return 1;

    return pthread_mutex_init(*mutex, attr);

}

int ZSTD_pthread_mutex_destroy(ZSTD_pthread_mutex_t* mutex)

{

    assert(mutex != NULL);

    if (!*mutex)

        return 0;

    {

        int const ret = pthread_mutex_destroy(*mutex);

        ZSTD_free(*mutex);

        return ret;

    }

}

int ZSTD_pthread_cond_init(ZSTD_pthread_cond_t* cond, pthread_condattr_t const* attr)

{

    assert(cond != NULL);

    *cond = (pthread_cond_t*)ZSTD_malloc(sizeof(pthread_cond_t));

    if (!*cond)

        return 1;

    return pthread_cond_init(*cond, attr);

}

int ZSTD_pthread_cond_destroy(ZSTD_pthread_cond_t* cond)

{

    assert(cond != NULL);

    if (!*cond)

        return 0;

    {

        int const ret = pthread_cond_destroy(*cond);

        ZSTD_free(*cond);

        return ret;

    }

}

#endif