/*
  * 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. */
 
 #define WIN32_LEAN_AND_MEAN
 #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/time.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
 

 static av_unused unsigned __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)

 {
     thread->func   = start_routine;
     thread->arg    = arg;

 #if HAVE_WINRT
     thread->handle = (void*)CreateThread(NULL, 0, win32thread_worker, thread,
                                            0, NULL);
 #else

     thread->handle = (void*)_beginthreadex(NULL, 0, win32thread_worker, thread,
                                            0, NULL);

 #endif

     return !thread->handle;
 }
 

 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);

     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 */