mov: Adjust variable types to fix format warnings
[ffmpeg.git] / compat / w32pthreads.h
1 /*
2  * Copyright (C) 2010-2011 x264 project
3  *
4  * Authors: Steven Walters <kemuri9@gmail.com>
5  *          Pegasys Inc. <http://www.pegasys-inc.com>
6  *
7  * This file is part of Libav.
8  *
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.
13  *
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.
18  *
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
22  */
23
24 /**
25  * @file
26  * w32threads to pthreads wrapper
27  */
28
29 #ifndef LIBAV_COMPAT_W32PTHREADS_H
30 #define LIBAV_COMPAT_W32PTHREADS_H
31
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
34  * library.
35  * As most functions here are used without checking return values,
36  * only implement return values as necessary. */
37
38 #define WIN32_LEAN_AND_MEAN
39 #include <windows.h>
40 #include <process.h>
41
42 #include "libavutil/attributes.h"
43 #include "libavutil/internal.h"
44 #include "libavutil/mem.h"
45
46 typedef struct pthread_t {
47     void *handle;
48     void *(*func)(void* arg);
49     void *arg;
50     void *ret;
51 } pthread_t;
52
53 /* the conditional variable api for windows 6.0+ uses critical sections and
54  * not mutexes */
55 typedef CRITICAL_SECTION pthread_mutex_t;
56
57 /* This is the CONDITION_VARIABLE typedef for using Windows' native
58  * conditional variables on kernels 6.0+. */
59 #if HAVE_CONDITION_VARIABLE_PTR
60 typedef CONDITION_VARIABLE pthread_cond_t;
61 #else
62 typedef struct pthread_cond_t {
63     void *Ptr;
64 } pthread_cond_t;
65 #endif
66
67 #if _WIN32_WINNT >= 0x0600
68 #define InitializeCriticalSection(x) InitializeCriticalSectionEx(x, 0, 0)
69 #define WaitForSingleObject(a, b) WaitForSingleObjectEx(a, b, FALSE)
70 #endif
71
72 static av_unused unsigned __stdcall attribute_align_arg win32thread_worker(void *arg)
73 {
74     pthread_t *h = arg;
75     h->ret = h->func(h->arg);
76     return 0;
77 }
78
79 static av_unused int pthread_create(pthread_t *thread, const void *unused_attr,
80                                     void *(*start_routine)(void*), void *arg)
81 {
82     thread->func   = start_routine;
83     thread->arg    = arg;
84     thread->handle = (void*)_beginthreadex(NULL, 0, win32thread_worker, thread,
85                                            0, NULL);
86     return !thread->handle;
87 }
88
89 static av_unused void pthread_join(pthread_t thread, void **value_ptr)
90 {
91     DWORD ret = WaitForSingleObject(thread.handle, INFINITE);
92     if (ret != WAIT_OBJECT_0)
93         return;
94     if (value_ptr)
95         *value_ptr = thread.ret;
96     CloseHandle(thread.handle);
97 }
98
99 static inline int pthread_mutex_init(pthread_mutex_t *m, void* attr)
100 {
101     InitializeCriticalSection(m);
102     return 0;
103 }
104 static inline int pthread_mutex_destroy(pthread_mutex_t *m)
105 {
106     DeleteCriticalSection(m);
107     return 0;
108 }
109 static inline int pthread_mutex_lock(pthread_mutex_t *m)
110 {
111     EnterCriticalSection(m);
112     return 0;
113 }
114 static inline int pthread_mutex_unlock(pthread_mutex_t *m)
115 {
116     LeaveCriticalSection(m);
117     return 0;
118 }
119
120 #if _WIN32_WINNT >= 0x0600
121 static inline void pthread_cond_init(pthread_cond_t *cond, const void *unused_attr)
122 {
123     InitializeConditionVariable(cond);
124 }
125
126 /* native condition variables do not destroy */
127 static inline void pthread_cond_destroy(pthread_cond_t *cond)
128 {
129     return;
130 }
131
132 static inline void pthread_cond_broadcast(pthread_cond_t *cond)
133 {
134     WakeAllConditionVariable(cond);
135 }
136
137 static inline int pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex)
138 {
139     SleepConditionVariableCS(cond, mutex, INFINITE);
140     return 0;
141 }
142
143 static inline void pthread_cond_signal(pthread_cond_t *cond)
144 {
145     WakeConditionVariable(cond);
146 }
147
148 #else // _WIN32_WINNT < 0x0600
149 /* for pre-Windows 6.0 platforms we need to define and use our own condition
150  * variable and api */
151 typedef struct  win32_cond_t {
152     pthread_mutex_t mtx_broadcast;
153     pthread_mutex_t mtx_waiter_count;
154     volatile int waiter_count;
155     HANDLE semaphore;
156     HANDLE waiters_done;
157     volatile int is_broadcast;
158 } win32_cond_t;
159
160 /* function pointers to conditional variable API on windows 6.0+ kernels */
161 static void (WINAPI *cond_broadcast)(pthread_cond_t *cond);
162 static void (WINAPI *cond_init)(pthread_cond_t *cond);
163 static void (WINAPI *cond_signal)(pthread_cond_t *cond);
164 static BOOL (WINAPI *cond_wait)(pthread_cond_t *cond, pthread_mutex_t *mutex,
165                                 DWORD milliseconds);
166
167 static av_unused void pthread_cond_init(pthread_cond_t *cond, const void *unused_attr)
168 {
169     win32_cond_t *win32_cond = NULL;
170     if (cond_init) {
171         cond_init(cond);
172         return;
173     }
174
175     /* non native condition variables */
176     win32_cond = av_mallocz(sizeof(win32_cond_t));
177     if (!win32_cond)
178         return;
179     cond->Ptr = win32_cond;
180     win32_cond->semaphore = CreateSemaphore(NULL, 0, 0x7fffffff, NULL);
181     if (!win32_cond->semaphore)
182         return;
183     win32_cond->waiters_done = CreateEvent(NULL, TRUE, FALSE, NULL);
184     if (!win32_cond->waiters_done)
185         return;
186
187     pthread_mutex_init(&win32_cond->mtx_waiter_count, NULL);
188     pthread_mutex_init(&win32_cond->mtx_broadcast, NULL);
189 }
190
191 static av_unused void pthread_cond_destroy(pthread_cond_t *cond)
192 {
193     win32_cond_t *win32_cond = cond->Ptr;
194     /* native condition variables do not destroy */
195     if (cond_init)
196         return;
197
198     /* non native condition variables */
199     CloseHandle(win32_cond->semaphore);
200     CloseHandle(win32_cond->waiters_done);
201     pthread_mutex_destroy(&win32_cond->mtx_waiter_count);
202     pthread_mutex_destroy(&win32_cond->mtx_broadcast);
203     av_freep(&win32_cond);
204     cond->Ptr = NULL;
205 }
206
207 static av_unused void pthread_cond_broadcast(pthread_cond_t *cond)
208 {
209     win32_cond_t *win32_cond = cond->Ptr;
210     int have_waiter;
211
212     if (cond_broadcast) {
213         cond_broadcast(cond);
214         return;
215     }
216
217     /* non native condition variables */
218     pthread_mutex_lock(&win32_cond->mtx_broadcast);
219     pthread_mutex_lock(&win32_cond->mtx_waiter_count);
220     have_waiter = 0;
221
222     if (win32_cond->waiter_count) {
223         win32_cond->is_broadcast = 1;
224         have_waiter = 1;
225     }
226
227     if (have_waiter) {
228         ReleaseSemaphore(win32_cond->semaphore, win32_cond->waiter_count, NULL);
229         pthread_mutex_unlock(&win32_cond->mtx_waiter_count);
230         WaitForSingleObject(win32_cond->waiters_done, INFINITE);
231         ResetEvent(win32_cond->waiters_done);
232         win32_cond->is_broadcast = 0;
233     } else
234         pthread_mutex_unlock(&win32_cond->mtx_waiter_count);
235     pthread_mutex_unlock(&win32_cond->mtx_broadcast);
236 }
237
238 static av_unused int pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex)
239 {
240     win32_cond_t *win32_cond = cond->Ptr;
241     int last_waiter;
242     if (cond_wait) {
243         cond_wait(cond, mutex, INFINITE);
244         return 0;
245     }
246
247     /* non native condition variables */
248     pthread_mutex_lock(&win32_cond->mtx_broadcast);
249     pthread_mutex_lock(&win32_cond->mtx_waiter_count);
250     win32_cond->waiter_count++;
251     pthread_mutex_unlock(&win32_cond->mtx_waiter_count);
252     pthread_mutex_unlock(&win32_cond->mtx_broadcast);
253
254     // unlock the external mutex
255     pthread_mutex_unlock(mutex);
256     WaitForSingleObject(win32_cond->semaphore, INFINITE);
257
258     pthread_mutex_lock(&win32_cond->mtx_waiter_count);
259     win32_cond->waiter_count--;
260     last_waiter = !win32_cond->waiter_count || !win32_cond->is_broadcast;
261     pthread_mutex_unlock(&win32_cond->mtx_waiter_count);
262
263     if (last_waiter)
264         SetEvent(win32_cond->waiters_done);
265
266     // lock the external mutex
267     return pthread_mutex_lock(mutex);
268 }
269
270 static av_unused void pthread_cond_signal(pthread_cond_t *cond)
271 {
272     win32_cond_t *win32_cond = cond->Ptr;
273     int have_waiter;
274     if (cond_signal) {
275         cond_signal(cond);
276         return;
277     }
278
279     pthread_mutex_lock(&win32_cond->mtx_broadcast);
280
281     /* non-native condition variables */
282     pthread_mutex_lock(&win32_cond->mtx_waiter_count);
283     have_waiter = win32_cond->waiter_count;
284     pthread_mutex_unlock(&win32_cond->mtx_waiter_count);
285
286     if (have_waiter) {
287         ReleaseSemaphore(win32_cond->semaphore, 1, NULL);
288         WaitForSingleObject(win32_cond->waiters_done, INFINITE);
289         ResetEvent(win32_cond->waiters_done);
290     }
291
292     pthread_mutex_unlock(&win32_cond->mtx_broadcast);
293 }
294 #endif
295
296 static av_unused void w32thread_init(void)
297 {
298 #if _WIN32_WINNT < 0x0600
299     HANDLE kernel_dll = GetModuleHandle(TEXT("kernel32.dll"));
300     /* if one is available, then they should all be available */
301     cond_init      =
302         (void*)GetProcAddress(kernel_dll, "InitializeConditionVariable");
303     cond_broadcast =
304         (void*)GetProcAddress(kernel_dll, "WakeAllConditionVariable");
305     cond_signal    =
306         (void*)GetProcAddress(kernel_dll, "WakeConditionVariable");
307     cond_wait      =
308         (void*)GetProcAddress(kernel_dll, "SleepConditionVariableCS");
309 #endif
310
311 }
312
313 #endif /* LIBAV_COMPAT_W32PTHREADS_H */