| 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 FFmpeg. |
| 8 | * |
| 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. |
| 13 | * |
| 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. |
| 18 | * |
| 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 |
| 22 | */ |
| 23 | |
| 24 | /** |
| 25 | * @file |
| 26 | * w32threads to pthreads wrapper |
| 27 | */ |
| 28 | |
| 29 | #ifndef FFMPEG_COMPAT_W32PTHREADS_H |
| 30 | #define FFMPEG_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/common.h" |
| 44 | #include "libavutil/internal.h" |
| 45 | #include "libavutil/mem.h" |
| 46 | |
| 47 | typedef struct pthread_t { |
| 48 | void *handle; |
| 49 | void *(*func)(void* arg); |
| 50 | void *arg; |
| 51 | void *ret; |
| 52 | } pthread_t; |
| 53 | |
| 54 | /* the conditional variable api for windows 6.0+ uses critical sections and |
| 55 | * not mutexes */ |
| 56 | typedef CRITICAL_SECTION pthread_mutex_t; |
| 57 | |
| 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 { |
| 62 | void *ptr; |
| 63 | } pthread_cond_t; |
| 64 | |
| 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, |
| 71 | DWORD milliseconds); |
| 72 | #else |
| 73 | #define cond_init InitializeConditionVariable |
| 74 | #define cond_broadcast WakeAllConditionVariable |
| 75 | #define cond_signal WakeConditionVariable |
| 76 | #define cond_wait SleepConditionVariableCS |
| 77 | |
| 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), \ |
| 82 | EVENT_ALL_ACCESS) |
| 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) |
| 89 | #endif |
| 90 | |
| 91 | static av_unused unsigned __stdcall attribute_align_arg win32thread_worker(void *arg) |
| 92 | { |
| 93 | pthread_t *h = arg; |
| 94 | h->ret = h->func(h->arg); |
| 95 | return 0; |
| 96 | } |
| 97 | |
| 98 | static av_unused int pthread_create(pthread_t *thread, const void *unused_attr, |
| 99 | void *(*start_routine)(void*), void *arg) |
| 100 | { |
| 101 | thread->func = start_routine; |
| 102 | thread->arg = arg; |
| 103 | thread->handle = (void*)_beginthreadex(NULL, 0, win32thread_worker, thread, |
| 104 | 0, NULL); |
| 105 | return !thread->handle; |
| 106 | } |
| 107 | |
| 108 | static av_unused void pthread_join(pthread_t thread, void **value_ptr) |
| 109 | { |
| 110 | DWORD ret = WaitForSingleObject(thread.handle, INFINITE); |
| 111 | if (ret != WAIT_OBJECT_0) |
| 112 | return; |
| 113 | if (value_ptr) |
| 114 | *value_ptr = thread.ret; |
| 115 | CloseHandle(thread.handle); |
| 116 | } |
| 117 | |
| 118 | static inline int pthread_mutex_init(pthread_mutex_t *m, void* attr) |
| 119 | { |
| 120 | InitializeCriticalSection(m); |
| 121 | return 0; |
| 122 | } |
| 123 | static inline int pthread_mutex_destroy(pthread_mutex_t *m) |
| 124 | { |
| 125 | DeleteCriticalSection(m); |
| 126 | return 0; |
| 127 | } |
| 128 | static inline int pthread_mutex_lock(pthread_mutex_t *m) |
| 129 | { |
| 130 | EnterCriticalSection(m); |
| 131 | return 0; |
| 132 | } |
| 133 | static inline int pthread_mutex_unlock(pthread_mutex_t *m) |
| 134 | { |
| 135 | LeaveCriticalSection(m); |
| 136 | return 0; |
| 137 | } |
| 138 | |
| 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; |
| 145 | HANDLE semaphore; |
| 146 | HANDLE waiters_done; |
| 147 | volatile int is_broadcast; |
| 148 | } win32_cond_t; |
| 149 | |
| 150 | static av_unused int pthread_cond_init(pthread_cond_t *cond, const void *unused_attr) |
| 151 | { |
| 152 | win32_cond_t *win32_cond = NULL; |
| 153 | if (cond_init) { |
| 154 | cond_init(cond); |
| 155 | return 0; |
| 156 | } |
| 157 | |
| 158 | /* non native condition variables */ |
| 159 | win32_cond = av_mallocz(sizeof(win32_cond_t)); |
| 160 | if (!win32_cond) |
| 161 | return ENOMEM; |
| 162 | cond->ptr = win32_cond; |
| 163 | win32_cond->semaphore = CreateSemaphore(NULL, 0, 0x7fffffff, NULL); |
| 164 | if (!win32_cond->semaphore) |
| 165 | return ENOMEM; |
| 166 | win32_cond->waiters_done = CreateEvent(NULL, TRUE, FALSE, NULL); |
| 167 | if (!win32_cond->waiters_done) |
| 168 | return ENOMEM; |
| 169 | |
| 170 | pthread_mutex_init(&win32_cond->mtx_waiter_count, NULL); |
| 171 | pthread_mutex_init(&win32_cond->mtx_broadcast, NULL); |
| 172 | return 0; |
| 173 | } |
| 174 | |
| 175 | static av_unused void pthread_cond_destroy(pthread_cond_t *cond) |
| 176 | { |
| 177 | win32_cond_t *win32_cond = cond->ptr; |
| 178 | /* native condition variables do not destroy */ |
| 179 | if (cond_init) |
| 180 | return; |
| 181 | |
| 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); |
| 188 | cond->ptr = NULL; |
| 189 | } |
| 190 | |
| 191 | static av_unused void pthread_cond_broadcast(pthread_cond_t *cond) |
| 192 | { |
| 193 | win32_cond_t *win32_cond = cond->ptr; |
| 194 | int have_waiter; |
| 195 | |
| 196 | if (cond_broadcast) { |
| 197 | cond_broadcast(cond); |
| 198 | return; |
| 199 | } |
| 200 | |
| 201 | /* non native condition variables */ |
| 202 | pthread_mutex_lock(&win32_cond->mtx_broadcast); |
| 203 | pthread_mutex_lock(&win32_cond->mtx_waiter_count); |
| 204 | have_waiter = 0; |
| 205 | |
| 206 | if (win32_cond->waiter_count) { |
| 207 | win32_cond->is_broadcast = 1; |
| 208 | have_waiter = 1; |
| 209 | } |
| 210 | |
| 211 | if (have_waiter) { |
| 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; |
| 217 | } else |
| 218 | pthread_mutex_unlock(&win32_cond->mtx_waiter_count); |
| 219 | pthread_mutex_unlock(&win32_cond->mtx_broadcast); |
| 220 | } |
| 221 | |
| 222 | static av_unused int pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex) |
| 223 | { |
| 224 | win32_cond_t *win32_cond = cond->ptr; |
| 225 | int last_waiter; |
| 226 | if (cond_wait) { |
| 227 | cond_wait(cond, mutex, INFINITE); |
| 228 | return 0; |
| 229 | } |
| 230 | |
| 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); |
| 237 | |
| 238 | // unlock the external mutex |
| 239 | pthread_mutex_unlock(mutex); |
| 240 | WaitForSingleObject(win32_cond->semaphore, INFINITE); |
| 241 | |
| 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); |
| 246 | |
| 247 | if (last_waiter) |
| 248 | SetEvent(win32_cond->waiters_done); |
| 249 | |
| 250 | // lock the external mutex |
| 251 | return pthread_mutex_lock(mutex); |
| 252 | } |
| 253 | |
| 254 | static av_unused void pthread_cond_signal(pthread_cond_t *cond) |
| 255 | { |
| 256 | win32_cond_t *win32_cond = cond->ptr; |
| 257 | int have_waiter; |
| 258 | if (cond_signal) { |
| 259 | cond_signal(cond); |
| 260 | return; |
| 261 | } |
| 262 | |
| 263 | pthread_mutex_lock(&win32_cond->mtx_broadcast); |
| 264 | |
| 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); |
| 269 | |
| 270 | if (have_waiter) { |
| 271 | ReleaseSemaphore(win32_cond->semaphore, 1, NULL); |
| 272 | WaitForSingleObject(win32_cond->waiters_done, INFINITE); |
| 273 | ResetEvent(win32_cond->waiters_done); |
| 274 | } |
| 275 | |
| 276 | pthread_mutex_unlock(&win32_cond->mtx_broadcast); |
| 277 | } |
| 278 | |
| 279 | static av_unused void w32thread_init(void) |
| 280 | { |
| 281 | #if _WIN32_WINNT < 0x0600 |
| 282 | HANDLE kernel_dll = GetModuleHandle(TEXT("kernel32.dll")); |
| 283 | /* if one is available, then they should all be available */ |
| 284 | cond_init = |
| 285 | (void*)GetProcAddress(kernel_dll, "InitializeConditionVariable"); |
| 286 | cond_broadcast = |
| 287 | (void*)GetProcAddress(kernel_dll, "WakeAllConditionVariable"); |
| 288 | cond_signal = |
| 289 | (void*)GetProcAddress(kernel_dll, "WakeConditionVariable"); |
| 290 | cond_wait = |
| 291 | (void*)GetProcAddress(kernel_dll, "SleepConditionVariableCS"); |
| 292 | #endif |
| 293 | |
| 294 | } |
| 295 | |
| 296 | #endif /* FFMPEG_COMPAT_W32PTHREADS_H */ |