contrib/python-zstandard/zstd/common/threading.c

dirstate-v2: freeze the on-disk format

It seems the format as reached a good balance. With a core of new capabilities
that motivated it initially and enough new feature and room for future
improvement to be a clear progress we can set a milestone for.

Having the format frozen will help the feature to get real life testing, outside
of the test suite.

The feature itself stay experimental but the config gains a new name to avoid
people enable non-frozen version by default.

If too many bugs are reported during the RC we might move the format back to
experimental and drop its support in future version (in favor of a new one)

Differential Revision: https://phab.mercurial-scm.org/D11709

/**
 * Copyright (c) 2016 Tino Reichardt
 * All rights reserved.
 *
 * 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 can contact the author at:
 * - zstdmt source repository: https://github.com/mcmilk/zstdmt
 */

/**
 * 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, based on :
 * http://www.cse.wustl.edu/~schmidt/win32-cv-1.html
 */


/* ===  Dependencies  === */
#include <process.h>
#include <errno.h>


/* ===  Implementation  === */

static unsigned __stdcall worker(void *arg)
{
    ZSTD_pthread_t* const thread = (ZSTD_pthread_t*) arg;
    thread->arg = thread->start_routine(thread->arg);
    return 0;
}

int ZSTD_pthread_create(ZSTD_pthread_t* thread, const void* unused,
            void* (*start_routine) (void*), void* arg)
{
    (void)unused;
    thread->arg = arg;
    thread->start_routine = start_routine;
    thread->handle = (HANDLE) _beginthreadex(NULL, 0, worker, thread, 0, NULL);

    if (!thread->handle)
        return errno;
    else
        return 0;
}

int ZSTD_pthread_join(ZSTD_pthread_t thread, void **value_ptr)
{
    DWORD result;

    if (!thread.handle) return 0;

    result = WaitForSingleObject(thread.handle, INFINITE);
    switch (result) {
    case WAIT_OBJECT_0:
        if (value_ptr) *value_ptr = thread.arg;
        return 0;
    case WAIT_ABANDONED:
        return EINVAL;
    default:
        return GetLastError();
    }
}

#endif   /* ZSTD_MULTITHREAD */

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

#include <stdlib.h>

int ZSTD_pthread_mutex_init(ZSTD_pthread_mutex_t* mutex, pthread_mutexattr_t const* attr)
{
    *mutex = (pthread_mutex_t*)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)
{
    if (!*mutex)
        return 0;
    {
        int const ret = pthread_mutex_destroy(*mutex);
        free(*mutex);
        return ret;
    }
}

int ZSTD_pthread_cond_init(ZSTD_pthread_cond_t* cond, pthread_condattr_t const* attr)
{
    *cond = (pthread_cond_t*)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)
{
    if (!*cond)
        return 0;
    {
        int const ret = pthread_cond_destroy(*cond);
        free(*cond);
        return ret;
    }
}

#endif