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 Libav.
9 * Libav 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 * Libav 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 Libav; 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 AVCODEC_W32PTHREADS_H
30 #define AVCODEC_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
44 void *(*func)(void* arg);
49 /* the conditional variable api for windows 6.0+ uses critical sections and
51 typedef CRITICAL_SECTION pthread_mutex_t;
53 /* This is the CONDITIONAL_VARIABLE typedef for using Window's native
54 * conditional variables on kernels 6.0+.
55 * MinGW does not currently have this typedef. */
60 /* function pointers to conditional variable API on windows 6.0+ kernels */
61 static void (WINAPI *cond_broadcast)(pthread_cond_t *cond);
62 static void (WINAPI *cond_init)(pthread_cond_t *cond);
63 static void (WINAPI *cond_signal)(pthread_cond_t *cond);
64 static BOOL (WINAPI *cond_wait)(pthread_cond_t *cond, pthread_mutex_t *mutex,
67 static unsigned __stdcall attribute_align_arg win32thread_worker(void *arg)
70 h->ret = h->func(h->arg);
74 static int pthread_create(pthread_t *thread, const void *unused_attr,
75 void *(*start_routine)(void*), void *arg)
77 thread->func = start_routine;
79 thread->handle = (void*)_beginthreadex(NULL, 0, win32thread_worker, thread,
81 return !thread->handle;
84 static void pthread_join(pthread_t thread, void **value_ptr)
86 DWORD ret = WaitForSingleObject(thread.handle, INFINITE);
87 if (ret != WAIT_OBJECT_0)
90 *value_ptr = thread.ret;
91 CloseHandle(thread.handle);
94 #define pthread_mutex_init(m, a) InitializeCriticalSection(m)
95 #define pthread_mutex_destroy(m) DeleteCriticalSection(m)
96 #define pthread_mutex_lock(m) EnterCriticalSection(m)
97 #define pthread_mutex_unlock(m) LeaveCriticalSection(m)
99 /* for pre-Windows 6.0 platforms we need to define and use our own condition
100 * variable and api */
102 pthread_mutex_t mtx_waiter_count;
103 volatile int waiter_count;
107 static void pthread_cond_init(pthread_cond_t *cond, const void *unused_attr)
109 win32_cond_t *win32_cond = NULL;
115 /* non native condition variables */
116 win32_cond = av_mallocz(sizeof(win32_cond_t));
119 cond->ptr = win32_cond;
120 win32_cond->semaphore = CreateSemaphore(NULL, 0, 0x7fffffff, NULL);
121 if (!win32_cond->semaphore)
124 pthread_mutex_init(&win32_cond->mtx_waiter_count, NULL);
127 static void pthread_cond_destroy(pthread_cond_t *cond)
129 win32_cond_t *win32_cond = cond->ptr;
130 /* native condition variables do not destroy */
134 /* non native condition variables */
135 CloseHandle(win32_cond->semaphore);
136 pthread_mutex_destroy(&win32_cond->mtx_waiter_count);
137 av_freep(&win32_cond);
141 static void pthread_cond_broadcast(pthread_cond_t *cond)
143 win32_cond_t *win32_cond = cond->ptr;
144 if (cond_broadcast) {
145 cond_broadcast(cond);
149 /* non native condition variables */
150 pthread_mutex_lock(&win32_cond->mtx_waiter_count);
151 if (win32_cond->waiter_count) {
152 ReleaseSemaphore(win32_cond->semaphore, win32_cond->waiter_count, NULL);
153 win32_cond->waiter_count = 0;
155 pthread_mutex_unlock(&win32_cond->mtx_waiter_count);
158 static void pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex)
160 win32_cond_t *win32_cond = cond->ptr;
162 cond_wait(cond, mutex, INFINITE);
166 /* non native condition variables */
167 pthread_mutex_lock(&win32_cond->mtx_waiter_count);
168 win32_cond->waiter_count++;
169 pthread_mutex_unlock(&win32_cond->mtx_waiter_count);
171 pthread_mutex_unlock(mutex);
172 WaitForSingleObject(win32_cond->semaphore, INFINITE);
173 pthread_mutex_lock(mutex);
176 static void pthread_cond_signal(pthread_cond_t *cond)
178 win32_cond_t *win32_cond = cond->ptr;
184 /* non-native condition variables */
185 pthread_mutex_lock(&win32_cond->mtx_waiter_count);
186 if (win32_cond->waiter_count) {
187 ReleaseSemaphore(win32_cond->semaphore, 1, NULL);
188 win32_cond->waiter_count--;
190 pthread_mutex_unlock(&win32_cond->mtx_waiter_count);
193 static void w32thread_init(void)
195 HANDLE kernel_dll = GetModuleHandle(TEXT("kernel32.dll"));
196 /* if one is available, then they should all be available */
198 (void*)GetProcAddress(kernel_dll, "InitializeConditionVariable");
200 (void*)GetProcAddress(kernel_dll, "WakeAllConditionVariable");
202 (void*)GetProcAddress(kernel_dll, "WakeConditionVariable");
204 (void*)GetProcAddress(kernel_dll, "SleepConditionVariableCS");
207 #endif /* AVCODEC_W32PTHREADS_H */