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/common.h"
43 #include "libavutil/internal.h"
44 #include "libavutil/mem.h"
46 typedef struct pthread_t {
48 void *(*func)(void* arg);
53 /* the conditional variable api for windows 6.0+ uses critical sections and
55 typedef CRITICAL_SECTION pthread_mutex_t;
57 /* This is the CONDITIONAL_VARIABLE typedef for using Window's native
58 * conditional variables on kernels 6.0+.
59 * MinGW does not currently have this typedef. */
60 typedef struct pthread_cond_t {
64 /* function pointers to conditional variable API on windows 6.0+ kernels */
65 #if _WIN32_WINNT < 0x0600
66 static void (WINAPI *cond_broadcast)(pthread_cond_t *cond);
67 static void (WINAPI *cond_init)(pthread_cond_t *cond);
68 static void (WINAPI *cond_signal)(pthread_cond_t *cond);
69 static BOOL (WINAPI *cond_wait)(pthread_cond_t *cond, pthread_mutex_t *mutex,
72 #define cond_init InitializeConditionVariable
73 #define cond_broadcast WakeAllConditionVariable
74 #define cond_signal WakeConditionVariable
75 #define cond_wait SleepConditionVariableCS
78 static unsigned __stdcall attribute_align_arg win32thread_worker(void *arg)
81 h->ret = h->func(h->arg);
85 static int pthread_create(pthread_t *thread, const void *unused_attr,
86 void *(*start_routine)(void*), void *arg)
88 thread->func = start_routine;
90 thread->handle = (void*)_beginthreadex(NULL, 0, win32thread_worker, thread,
92 return !thread->handle;
95 static void pthread_join(pthread_t thread, void **value_ptr)
97 DWORD ret = WaitForSingleObject(thread.handle, INFINITE);
98 if (ret != WAIT_OBJECT_0)
101 *value_ptr = thread.ret;
102 CloseHandle(thread.handle);
105 static inline int pthread_mutex_init(pthread_mutex_t *m, void* attr)
107 InitializeCriticalSection(m);
110 static inline int pthread_mutex_destroy(pthread_mutex_t *m)
112 DeleteCriticalSection(m);
115 static inline int pthread_mutex_lock(pthread_mutex_t *m)
117 EnterCriticalSection(m);
120 static inline int pthread_mutex_unlock(pthread_mutex_t *m)
122 LeaveCriticalSection(m);
126 /* for pre-Windows 6.0 platforms we need to define and use our own condition
127 * variable and api */
128 typedef struct win32_cond_t {
129 pthread_mutex_t mtx_broadcast;
130 pthread_mutex_t mtx_waiter_count;
131 volatile int waiter_count;
134 volatile int is_broadcast;
137 static void pthread_cond_init(pthread_cond_t *cond, const void *unused_attr)
139 win32_cond_t *win32_cond = NULL;
145 /* non native condition variables */
146 win32_cond = av_mallocz(sizeof(win32_cond_t));
149 cond->ptr = win32_cond;
150 win32_cond->semaphore = CreateSemaphore(NULL, 0, 0x7fffffff, NULL);
151 if (!win32_cond->semaphore)
153 win32_cond->waiters_done = CreateEvent(NULL, TRUE, FALSE, NULL);
154 if (!win32_cond->waiters_done)
157 pthread_mutex_init(&win32_cond->mtx_waiter_count, NULL);
158 pthread_mutex_init(&win32_cond->mtx_broadcast, NULL);
161 static void pthread_cond_destroy(pthread_cond_t *cond)
163 win32_cond_t *win32_cond = cond->ptr;
164 /* native condition variables do not destroy */
168 /* non native condition variables */
169 CloseHandle(win32_cond->semaphore);
170 CloseHandle(win32_cond->waiters_done);
171 pthread_mutex_destroy(&win32_cond->mtx_waiter_count);
172 pthread_mutex_destroy(&win32_cond->mtx_broadcast);
173 av_freep(&win32_cond);
177 static void pthread_cond_broadcast(pthread_cond_t *cond)
179 win32_cond_t *win32_cond = cond->ptr;
182 if (cond_broadcast) {
183 cond_broadcast(cond);
187 /* non native condition variables */
188 pthread_mutex_lock(&win32_cond->mtx_broadcast);
189 pthread_mutex_lock(&win32_cond->mtx_waiter_count);
192 if (win32_cond->waiter_count) {
193 win32_cond->is_broadcast = 1;
198 ReleaseSemaphore(win32_cond->semaphore, win32_cond->waiter_count, NULL);
199 pthread_mutex_unlock(&win32_cond->mtx_waiter_count);
200 WaitForSingleObject(win32_cond->waiters_done, INFINITE);
201 ResetEvent(win32_cond->waiters_done);
202 win32_cond->is_broadcast = 0;
204 pthread_mutex_unlock(&win32_cond->mtx_waiter_count);
205 pthread_mutex_unlock(&win32_cond->mtx_broadcast);
208 static int pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex)
210 win32_cond_t *win32_cond = cond->ptr;
213 cond_wait(cond, mutex, INFINITE);
217 /* non native condition variables */
218 pthread_mutex_lock(&win32_cond->mtx_broadcast);
219 pthread_mutex_lock(&win32_cond->mtx_waiter_count);
220 win32_cond->waiter_count++;
221 pthread_mutex_unlock(&win32_cond->mtx_waiter_count);
222 pthread_mutex_unlock(&win32_cond->mtx_broadcast);
224 // unlock the external mutex
225 pthread_mutex_unlock(mutex);
226 WaitForSingleObject(win32_cond->semaphore, INFINITE);
228 pthread_mutex_lock(&win32_cond->mtx_waiter_count);
229 win32_cond->waiter_count--;
230 last_waiter = !win32_cond->waiter_count || !win32_cond->is_broadcast;
231 pthread_mutex_unlock(&win32_cond->mtx_waiter_count);
234 SetEvent(win32_cond->waiters_done);
236 // lock the external mutex
237 return pthread_mutex_lock(mutex);
240 static void pthread_cond_signal(pthread_cond_t *cond)
242 win32_cond_t *win32_cond = cond->ptr;
249 pthread_mutex_lock(&win32_cond->mtx_broadcast);
251 /* non-native condition variables */
252 pthread_mutex_lock(&win32_cond->mtx_waiter_count);
253 have_waiter = win32_cond->waiter_count;
254 pthread_mutex_unlock(&win32_cond->mtx_waiter_count);
257 ReleaseSemaphore(win32_cond->semaphore, 1, NULL);
258 WaitForSingleObject(win32_cond->waiters_done, INFINITE);
259 ResetEvent(win32_cond->waiters_done);
262 pthread_mutex_unlock(&win32_cond->mtx_broadcast);
265 static void w32thread_init(void)
267 #if _WIN32_WINNT < 0x0600
268 HANDLE kernel_dll = GetModuleHandle(TEXT("kernel32.dll"));
269 /* if one is available, then they should all be available */
271 (void*)GetProcAddress(kernel_dll, "InitializeConditionVariable");
273 (void*)GetProcAddress(kernel_dll, "WakeAllConditionVariable");
275 (void*)GetProcAddress(kernel_dll, "WakeConditionVariable");
277 (void*)GetProcAddress(kernel_dll, "SleepConditionVariableCS");
282 #endif /* FFMPEG_COMPAT_W32PTHREADS_H */