2 * Copyright (C) 2010-2011 x264 project
4 * Authors: Steven Walters <kemuri9@gmail.com>
5 * Pegasys Inc. <http://www.pegasys-inc.com>
7 * This file is part of FFmpeg.
9 * FFmpeg is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Lesser General Public
11 * License as published by the Free Software Foundation; either
12 * version 2.1 of the License, or (at your option) any later version.
14 * FFmpeg is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * Lesser General Public License for more details.
19 * You should have received a copy of the GNU Lesser General Public
20 * License along with FFmpeg; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
26 * w32threads to pthreads wrapper
29 #ifndef FFMPEG_COMPAT_W32PTHREADS_H
30 #define FFMPEG_COMPAT_W32PTHREADS_H
32 /* Build up a pthread-like API using underlying Windows API. Have only static
33 * methods so as to not conflict with a potentially linked in pthread-win32
35 * As most functions here are used without checking return values,
36 * only implement return values as necessary. */
38 #define WIN32_LEAN_AND_MEAN
42 #include "libavutil/attributes.h"
43 #include "libavutil/common.h"
44 #include "libavutil/internal.h"
45 #include "libavutil/mem.h"
47 typedef struct pthread_t
{
49 void *(*func
)(void* arg
);
54 /* the conditional variable api for windows 6.0+ uses critical sections and
56 typedef CRITICAL_SECTION pthread_mutex_t
;
58 /* This is the CONDITION_VARIABLE typedef for using Windows' native
59 * conditional variables on kernels 6.0+. */
60 #if HAVE_CONDITION_VARIABLE_PTR
61 typedef CONDITION_VARIABLE pthread_cond_t
;
63 typedef struct pthread_cond_t
{
68 #if _WIN32_WINNT >= 0x0600
69 #define InitializeCriticalSection(x) InitializeCriticalSectionEx(x, 0, 0)
70 #define WaitForSingleObject(a, b) WaitForSingleObjectEx(a, b, FALSE)
73 static av_unused
unsigned __stdcall attribute_align_arg
win32thread_worker(void *arg
)
76 h
->ret
= h
->func(h
->arg
);
80 static av_unused
int pthread_create(pthread_t
*thread
, const void *unused_attr
,
81 void *(*start_routine
)(void*), void *arg
)
83 thread
->func
= start_routine
;
85 thread
->handle
= (void*)_beginthreadex(NULL
, 0, win32thread_worker
, thread
,
87 return !thread
->handle
;
90 static av_unused
void pthread_join(pthread_t thread
, void **value_ptr
)
92 DWORD ret
= WaitForSingleObject(thread
.handle
, INFINITE
);
93 if (ret
!= WAIT_OBJECT_0
)
96 *value_ptr
= thread
.ret
;
97 CloseHandle(thread
.handle
);
100 static inline int pthread_mutex_init(pthread_mutex_t
*m
, void* attr
)
102 InitializeCriticalSection(m
);
105 static inline int pthread_mutex_destroy(pthread_mutex_t
*m
)
107 DeleteCriticalSection(m
);
110 static inline int pthread_mutex_lock(pthread_mutex_t
*m
)
112 EnterCriticalSection(m
);
115 static inline int pthread_mutex_unlock(pthread_mutex_t
*m
)
117 LeaveCriticalSection(m
);
121 #if _WIN32_WINNT >= 0x0600
122 static inline int pthread_cond_init(pthread_cond_t
*cond
, const void *unused_attr
)
124 InitializeConditionVariable(cond
);
128 /* native condition variables do not destroy */
129 static inline void pthread_cond_destroy(pthread_cond_t
*cond
)
134 static inline void pthread_cond_broadcast(pthread_cond_t
*cond
)
136 WakeAllConditionVariable(cond
);
139 static inline int pthread_cond_wait(pthread_cond_t
*cond
, pthread_mutex_t
*mutex
)
141 SleepConditionVariableCS(cond
, mutex
, INFINITE
);
145 static inline void pthread_cond_signal(pthread_cond_t
*cond
)
147 WakeConditionVariable(cond
);
150 #else // _WIN32_WINNT < 0x0600
151 /* for pre-Windows 6.0 platforms we need to define and use our own condition
152 * variable and api */
153 typedef struct win32_cond_t
{
154 pthread_mutex_t mtx_broadcast
;
155 pthread_mutex_t mtx_waiter_count
;
156 volatile int waiter_count
;
159 volatile int is_broadcast
;
162 /* function pointers to conditional variable API on windows 6.0+ kernels */
163 static void (WINAPI
*cond_broadcast
)(pthread_cond_t
*cond
);
164 static void (WINAPI
*cond_init
)(pthread_cond_t
*cond
);
165 static void (WINAPI
*cond_signal
)(pthread_cond_t
*cond
);
166 static BOOL (WINAPI
*cond_wait
)(pthread_cond_t
*cond
, pthread_mutex_t
*mutex
,
169 static av_unused
int pthread_cond_init(pthread_cond_t
*cond
, const void *unused_attr
)
171 win32_cond_t
*win32_cond
= NULL
;
177 /* non native condition variables */
178 win32_cond
= av_mallocz(sizeof(win32_cond_t
));
181 cond
->Ptr
= win32_cond
;
182 win32_cond
->semaphore
= CreateSemaphore(NULL
, 0, 0x7fffffff, NULL
);
183 if (!win32_cond
->semaphore
)
185 win32_cond
->waiters_done
= CreateEvent(NULL
, TRUE
, FALSE
, NULL
);
186 if (!win32_cond
->waiters_done
)
189 pthread_mutex_init(&win32_cond
->mtx_waiter_count
, NULL
);
190 pthread_mutex_init(&win32_cond
->mtx_broadcast
, NULL
);
194 static av_unused
void pthread_cond_destroy(pthread_cond_t
*cond
)
196 win32_cond_t
*win32_cond
= cond
->Ptr
;
197 /* native condition variables do not destroy */
201 /* non native condition variables */
202 CloseHandle(win32_cond
->semaphore
);
203 CloseHandle(win32_cond
->waiters_done
);
204 pthread_mutex_destroy(&win32_cond
->mtx_waiter_count
);
205 pthread_mutex_destroy(&win32_cond
->mtx_broadcast
);
206 av_freep(&win32_cond
);
210 static av_unused
void pthread_cond_broadcast(pthread_cond_t
*cond
)
212 win32_cond_t
*win32_cond
= cond
->Ptr
;
215 if (cond_broadcast
) {
216 cond_broadcast(cond
);
220 /* non native condition variables */
221 pthread_mutex_lock(&win32_cond
->mtx_broadcast
);
222 pthread_mutex_lock(&win32_cond
->mtx_waiter_count
);
225 if (win32_cond
->waiter_count
) {
226 win32_cond
->is_broadcast
= 1;
231 ReleaseSemaphore(win32_cond
->semaphore
, win32_cond
->waiter_count
, NULL
);
232 pthread_mutex_unlock(&win32_cond
->mtx_waiter_count
);
233 WaitForSingleObject(win32_cond
->waiters_done
, INFINITE
);
234 ResetEvent(win32_cond
->waiters_done
);
235 win32_cond
->is_broadcast
= 0;
237 pthread_mutex_unlock(&win32_cond
->mtx_waiter_count
);
238 pthread_mutex_unlock(&win32_cond
->mtx_broadcast
);
241 static av_unused
int pthread_cond_wait(pthread_cond_t
*cond
, pthread_mutex_t
*mutex
)
243 win32_cond_t
*win32_cond
= cond
->Ptr
;
246 cond_wait(cond
, mutex
, INFINITE
);
250 /* non native condition variables */
251 pthread_mutex_lock(&win32_cond
->mtx_broadcast
);
252 pthread_mutex_lock(&win32_cond
->mtx_waiter_count
);
253 win32_cond
->waiter_count
++;
254 pthread_mutex_unlock(&win32_cond
->mtx_waiter_count
);
255 pthread_mutex_unlock(&win32_cond
->mtx_broadcast
);
257 // unlock the external mutex
258 pthread_mutex_unlock(mutex
);
259 WaitForSingleObject(win32_cond
->semaphore
, INFINITE
);
261 pthread_mutex_lock(&win32_cond
->mtx_waiter_count
);
262 win32_cond
->waiter_count
--;
263 last_waiter
= !win32_cond
->waiter_count
|| !win32_cond
->is_broadcast
;
264 pthread_mutex_unlock(&win32_cond
->mtx_waiter_count
);
267 SetEvent(win32_cond
->waiters_done
);
269 // lock the external mutex
270 return pthread_mutex_lock(mutex
);
273 static av_unused
void pthread_cond_signal(pthread_cond_t
*cond
)
275 win32_cond_t
*win32_cond
= cond
->Ptr
;
282 pthread_mutex_lock(&win32_cond
->mtx_broadcast
);
284 /* non-native condition variables */
285 pthread_mutex_lock(&win32_cond
->mtx_waiter_count
);
286 have_waiter
= win32_cond
->waiter_count
;
287 pthread_mutex_unlock(&win32_cond
->mtx_waiter_count
);
290 ReleaseSemaphore(win32_cond
->semaphore
, 1, NULL
);
291 WaitForSingleObject(win32_cond
->waiters_done
, INFINITE
);
292 ResetEvent(win32_cond
->waiters_done
);
295 pthread_mutex_unlock(&win32_cond
->mtx_broadcast
);
299 static av_unused
void w32thread_init(void)
301 #if _WIN32_WINNT < 0x0600
302 HANDLE kernel_dll
= GetModuleHandle(TEXT("kernel32.dll"));
303 /* if one is available, then they should all be available */
305 (void*)GetProcAddress(kernel_dll
, "InitializeConditionVariable");
307 (void*)GetProcAddress(kernel_dll
, "WakeAllConditionVariable");
309 (void*)GetProcAddress(kernel_dll
, "WakeConditionVariable");
311 (void*)GetProcAddress(kernel_dll
, "SleepConditionVariableCS");
316 #endif /* FFMPEG_COMPAT_W32PTHREADS_H */