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 CONDITIONAL_VARIABLE typedef for using Window's native
59 * conditional variables on kernels 6.0+.
60 * MinGW does not currently have this typedef. */
61 typedef struct pthread_cond_t
{
65 /* function pointers to conditional variable API on windows 6.0+ kernels */
66 #if _WIN32_WINNT < 0x0600
67 static void (WINAPI
*cond_broadcast
)(pthread_cond_t
*cond
);
68 static void (WINAPI
*cond_init
)(pthread_cond_t
*cond
);
69 static void (WINAPI
*cond_signal
)(pthread_cond_t
*cond
);
70 static BOOL (WINAPI
*cond_wait
)(pthread_cond_t
*cond
, pthread_mutex_t
*mutex
,
73 #define cond_init InitializeConditionVariable
74 #define cond_broadcast WakeAllConditionVariable
75 #define cond_signal WakeConditionVariable
76 #define cond_wait SleepConditionVariableCS
78 #define CreateEvent(a, reset, init, name) \
79 CreateEventEx(a, name, \
80 (reset ? CREATE_EVENT_MANUAL_RESET : 0) | \
81 (init ? CREATE_EVENT_INITIAL_SET : 0), \
83 // CreateSemaphoreExA seems to be desktop-only, but as long as we don't
84 // use named semaphores, it doesn't matter if we use the W version.
85 #define CreateSemaphore(a, b, c, d) \
86 CreateSemaphoreExW(a, b, c, d, 0, SEMAPHORE_ALL_ACCESS)
87 #define InitializeCriticalSection(x) InitializeCriticalSectionEx(x, 0, 0)
88 #define WaitForSingleObject(a, b) WaitForSingleObjectEx(a, b, FALSE)
91 static av_unused
unsigned __stdcall attribute_align_arg
win32thread_worker(void *arg
)
94 h
->ret
= h
->func(h
->arg
);
98 static av_unused
int pthread_create(pthread_t
*thread
, const void *unused_attr
,
99 void *(*start_routine
)(void*), void *arg
)
101 thread
->func
= start_routine
;
103 thread
->handle
= (void*)_beginthreadex(NULL
, 0, win32thread_worker
, thread
,
105 return !thread
->handle
;
108 static av_unused
void pthread_join(pthread_t thread
, void **value_ptr
)
110 DWORD ret
= WaitForSingleObject(thread
.handle
, INFINITE
);
111 if (ret
!= WAIT_OBJECT_0
)
114 *value_ptr
= thread
.ret
;
115 CloseHandle(thread
.handle
);
118 static inline int pthread_mutex_init(pthread_mutex_t
*m
, void* attr
)
120 InitializeCriticalSection(m
);
123 static inline int pthread_mutex_destroy(pthread_mutex_t
*m
)
125 DeleteCriticalSection(m
);
128 static inline int pthread_mutex_lock(pthread_mutex_t
*m
)
130 EnterCriticalSection(m
);
133 static inline int pthread_mutex_unlock(pthread_mutex_t
*m
)
135 LeaveCriticalSection(m
);
139 /* for pre-Windows 6.0 platforms we need to define and use our own condition
140 * variable and api */
141 typedef struct win32_cond_t
{
142 pthread_mutex_t mtx_broadcast
;
143 pthread_mutex_t mtx_waiter_count
;
144 volatile int waiter_count
;
147 volatile int is_broadcast
;
150 static av_unused
int pthread_cond_init(pthread_cond_t
*cond
, const void *unused_attr
)
152 win32_cond_t
*win32_cond
= NULL
;
158 /* non native condition variables */
159 win32_cond
= av_mallocz(sizeof(win32_cond_t
));
162 cond
->ptr
= win32_cond
;
163 win32_cond
->semaphore
= CreateSemaphore(NULL
, 0, 0x7fffffff, NULL
);
164 if (!win32_cond
->semaphore
)
166 win32_cond
->waiters_done
= CreateEvent(NULL
, TRUE
, FALSE
, NULL
);
167 if (!win32_cond
->waiters_done
)
170 pthread_mutex_init(&win32_cond
->mtx_waiter_count
, NULL
);
171 pthread_mutex_init(&win32_cond
->mtx_broadcast
, NULL
);
175 static av_unused
void pthread_cond_destroy(pthread_cond_t
*cond
)
177 win32_cond_t
*win32_cond
= cond
->ptr
;
178 /* native condition variables do not destroy */
182 /* non native condition variables */
183 CloseHandle(win32_cond
->semaphore
);
184 CloseHandle(win32_cond
->waiters_done
);
185 pthread_mutex_destroy(&win32_cond
->mtx_waiter_count
);
186 pthread_mutex_destroy(&win32_cond
->mtx_broadcast
);
187 av_freep(&win32_cond
);
191 static av_unused
void pthread_cond_broadcast(pthread_cond_t
*cond
)
193 win32_cond_t
*win32_cond
= cond
->ptr
;
196 if (cond_broadcast
) {
197 cond_broadcast(cond
);
201 /* non native condition variables */
202 pthread_mutex_lock(&win32_cond
->mtx_broadcast
);
203 pthread_mutex_lock(&win32_cond
->mtx_waiter_count
);
206 if (win32_cond
->waiter_count
) {
207 win32_cond
->is_broadcast
= 1;
212 ReleaseSemaphore(win32_cond
->semaphore
, win32_cond
->waiter_count
, NULL
);
213 pthread_mutex_unlock(&win32_cond
->mtx_waiter_count
);
214 WaitForSingleObject(win32_cond
->waiters_done
, INFINITE
);
215 ResetEvent(win32_cond
->waiters_done
);
216 win32_cond
->is_broadcast
= 0;
218 pthread_mutex_unlock(&win32_cond
->mtx_waiter_count
);
219 pthread_mutex_unlock(&win32_cond
->mtx_broadcast
);
222 static av_unused
int pthread_cond_wait(pthread_cond_t
*cond
, pthread_mutex_t
*mutex
)
224 win32_cond_t
*win32_cond
= cond
->ptr
;
227 cond_wait(cond
, mutex
, INFINITE
);
231 /* non native condition variables */
232 pthread_mutex_lock(&win32_cond
->mtx_broadcast
);
233 pthread_mutex_lock(&win32_cond
->mtx_waiter_count
);
234 win32_cond
->waiter_count
++;
235 pthread_mutex_unlock(&win32_cond
->mtx_waiter_count
);
236 pthread_mutex_unlock(&win32_cond
->mtx_broadcast
);
238 // unlock the external mutex
239 pthread_mutex_unlock(mutex
);
240 WaitForSingleObject(win32_cond
->semaphore
, INFINITE
);
242 pthread_mutex_lock(&win32_cond
->mtx_waiter_count
);
243 win32_cond
->waiter_count
--;
244 last_waiter
= !win32_cond
->waiter_count
|| !win32_cond
->is_broadcast
;
245 pthread_mutex_unlock(&win32_cond
->mtx_waiter_count
);
248 SetEvent(win32_cond
->waiters_done
);
250 // lock the external mutex
251 return pthread_mutex_lock(mutex
);
254 static av_unused
void pthread_cond_signal(pthread_cond_t
*cond
)
256 win32_cond_t
*win32_cond
= cond
->ptr
;
263 pthread_mutex_lock(&win32_cond
->mtx_broadcast
);
265 /* non-native condition variables */
266 pthread_mutex_lock(&win32_cond
->mtx_waiter_count
);
267 have_waiter
= win32_cond
->waiter_count
;
268 pthread_mutex_unlock(&win32_cond
->mtx_waiter_count
);
271 ReleaseSemaphore(win32_cond
->semaphore
, 1, NULL
);
272 WaitForSingleObject(win32_cond
->waiters_done
, INFINITE
);
273 ResetEvent(win32_cond
->waiters_done
);
276 pthread_mutex_unlock(&win32_cond
->mtx_broadcast
);
279 static av_unused
void w32thread_init(void)
281 #if _WIN32_WINNT < 0x0600
282 HANDLE kernel_dll
= GetModuleHandle(TEXT("kernel32.dll"));
283 /* if one is available, then they should all be available */
285 (void*)GetProcAddress(kernel_dll
, "InitializeConditionVariable");
287 (void*)GetProcAddress(kernel_dll
, "WakeAllConditionVariable");
289 (void*)GetProcAddress(kernel_dll
, "WakeConditionVariable");
291 (void*)GetProcAddress(kernel_dll
, "SleepConditionVariableCS");
296 #endif /* FFMPEG_COMPAT_W32PTHREADS_H */