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w32pthreads.h (5619B)

---

/*
* Copyright (C) 2010-2011 x264 project
*
* Authors: Steven Walters <kemuri9@gmail.com>
*          Pegasys Inc. <http://www.pegasys-inc.com>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/

/**
* @file
* w32threads to pthreads wrapper
*/

#ifndef COMPAT_W32PTHREADS_H
#define COMPAT_W32PTHREADS_H

/* Build up a pthread-like API using underlying Windows API. Have only static
* methods so as to not conflict with a potentially linked in pthread-win32
* library.
* As most functions here are used without checking return values,
* only implement return values as necessary. */

#include <windows.h>
#include <process.h>
#include <time.h>

#include "libavutil/attributes.h"
#include "libavutil/common.h"
#include "libavutil/internal.h"
#include "libavutil/mem.h"
#include "libavutil/fftime.h"

typedef struct pthread_t {
   void *handle;
   void *(*func)(void* arg);
   void *arg;
   void *ret;
} *pthread_t;

/* use light weight mutex/condition variable API for Windows Vista and later */
typedef SRWLOCK pthread_mutex_t;
typedef CONDITION_VARIABLE pthread_cond_t;

#define PTHREAD_MUTEX_INITIALIZER SRWLOCK_INIT
#define PTHREAD_COND_INITIALIZER CONDITION_VARIABLE_INIT

#define InitializeCriticalSection(x) InitializeCriticalSectionEx(x, 0, 0)
#define WaitForSingleObject(a, b) WaitForSingleObjectEx(a, b, FALSE)

#define PTHREAD_CANCEL_ENABLE 1
#define PTHREAD_CANCEL_DISABLE 0

#if HAVE_WINRT
#define THREADFUNC_RETTYPE DWORD
#else
#define THREADFUNC_RETTYPE unsigned
#endif

static av_unused THREADFUNC_RETTYPE
__stdcall attribute_align_arg win32thread_worker(void *arg)
{
   pthread_t h = (pthread_t)arg;
   h->ret = h->func(h->arg);
   return 0;
}

static av_unused int pthread_create(pthread_t *thread, const void *unused_attr,
                                   void *(*start_routine)(void*), void *arg)
{
   pthread_t ret;

   ret = av_mallocz(sizeof(*ret));
   if (!ret)
       return EAGAIN;

   ret->func   = start_routine;
   ret->arg    = arg;
#if HAVE_WINRT
   ret->handle = (void*)CreateThread(NULL, 0, win32thread_worker, ret,
                                     0, NULL);
#else
   ret->handle = (void*)_beginthreadex(NULL, 0, win32thread_worker, ret,
                                       0, NULL);
#endif

   if (!ret->handle) {
       av_free(ret);
       return EAGAIN;
   }

   *thread = ret;

   return 0;
}

static av_unused int pthread_join(pthread_t thread, void **value_ptr)
{
   DWORD ret = WaitForSingleObject(thread->handle, INFINITE);
   if (ret != WAIT_OBJECT_0) {
       if (ret == WAIT_ABANDONED)
           return EINVAL;
       else
           return EDEADLK;
   }
   if (value_ptr)
       *value_ptr = thread->ret;
   CloseHandle(thread->handle);
   av_free(thread);
   return 0;
}

static inline int pthread_mutex_init(pthread_mutex_t *m, void* attr)
{
   InitializeSRWLock(m);
   return 0;
}
static inline int pthread_mutex_destroy(pthread_mutex_t *m)
{
   /* Unlocked SWR locks use no resources */
   return 0;
}
static inline int pthread_mutex_lock(pthread_mutex_t *m)
{
   AcquireSRWLockExclusive(m);
   return 0;
}
static inline int pthread_mutex_unlock(pthread_mutex_t *m)
{
   ReleaseSRWLockExclusive(m);
   return 0;
}

typedef INIT_ONCE pthread_once_t;
#define PTHREAD_ONCE_INIT INIT_ONCE_STATIC_INIT

static av_unused int pthread_once(pthread_once_t *once_control, void (*init_routine)(void))
{
   BOOL pending = FALSE;
   InitOnceBeginInitialize(once_control, 0, &pending, NULL);
   if (pending)
       init_routine();
   InitOnceComplete(once_control, 0, NULL);
   return 0;
}

static inline int pthread_cond_init(pthread_cond_t *cond, const void *unused_attr)
{
   InitializeConditionVariable(cond);
   return 0;
}

/* native condition variables do not destroy */
static inline int pthread_cond_destroy(pthread_cond_t *cond)
{
   return 0;
}

static inline int pthread_cond_broadcast(pthread_cond_t *cond)
{
   WakeAllConditionVariable(cond);
   return 0;
}

static inline int pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex)
{
   SleepConditionVariableSRW(cond, mutex, INFINITE, 0);
   return 0;
}

static inline int pthread_cond_timedwait(pthread_cond_t *cond, pthread_mutex_t *mutex,
                                        const struct timespec *abstime)
{
   int64_t abs_milli = abstime->tv_sec * 1000LL + abstime->tv_nsec / 1000000;
   DWORD t = av_clip64(abs_milli - av_gettime() / 1000, 0, UINT32_MAX);

   if (!SleepConditionVariableSRW(cond, mutex, t, 0)) {
       DWORD err = GetLastError();
       if (err == ERROR_TIMEOUT)
           return ETIMEDOUT;
       else
           return EINVAL;
   }
   return 0;
}

static inline int pthread_cond_signal(pthread_cond_t *cond)
{
   WakeConditionVariable(cond);
   return 0;
}

static inline int pthread_setcancelstate(int state, int *oldstate)
{
   return 0;
}

#endif /* COMPAT_W32PTHREADS_H */