1 /*
2 * Copyright (c) 2016, Alliance for Open Media. All rights reserved
3 *
4 * This source code is subject to the terms of the BSD 2 Clause License and
5 * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
6 * was not distributed with this source code in the LICENSE file, you can
7 * obtain it at www.aomedia.org/license/software. If the Alliance for Open
8 * Media Patent License 1.0 was not distributed with this source code in the
9 * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
10 */
11 //
12 // Multi-threaded worker
13 //
14 // Original source:
15 // https://chromium.googlesource.com/webm/libwebp
16
17 #ifndef AOM_AOM_UTIL_AOM_THREAD_H_
18 #define AOM_AOM_UTIL_AOM_THREAD_H_
19
20 #include "config/aom_config.h"
21
22 #ifdef __cplusplus
23 extern "C" {
24 #endif
25
26 #define MAX_NUM_THREADS 64
27
28 #if CONFIG_MULTITHREAD
29
30 #if defined(_WIN32) && !HAVE_PTHREAD_H
31 #include <errno.h> // NOLINT
32 #include <process.h> // NOLINT
33 #include <windows.h> // NOLINT
34 typedef HANDLE pthread_t;
35 typedef CRITICAL_SECTION pthread_mutex_t;
36
37 #if _WIN32_WINNT < 0x0600
38 #error _WIN32_WINNT must target Windows Vista / Server 2008 or newer.
39 #endif
40 typedef CONDITION_VARIABLE pthread_cond_t;
41
42 #ifndef WINAPI_FAMILY_PARTITION
43 #define WINAPI_PARTITION_DESKTOP 1
44 #define WINAPI_FAMILY_PARTITION(x) x
45 #endif
46
47 #if !WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)
48 #define USE_CREATE_THREAD
49 #endif
50
51 //------------------------------------------------------------------------------
52 // simplistic pthread emulation layer
53
54 // _beginthreadex requires __stdcall
55 #define THREADFN unsigned int __stdcall
56 #define THREAD_RETURN(val) (unsigned int)((DWORD_PTR)val)
57
pthread_create(pthread_t * const thread,const void * attr,unsigned int (__stdcall * start)(void *),void * arg)58 static INLINE int pthread_create(pthread_t *const thread, const void *attr,
59 unsigned int(__stdcall *start)(void *),
60 void *arg) {
61 (void)attr;
62 #ifdef USE_CREATE_THREAD
63 *thread = CreateThread(NULL, /* lpThreadAttributes */
64 0, /* dwStackSize */
65 start, arg, 0, /* dwStackSize */
66 NULL); /* lpThreadId */
67 #else
68 *thread = (pthread_t)_beginthreadex(NULL, /* void *security */
69 0, /* unsigned stack_size */
70 start, arg, 0, /* unsigned initflag */
71 NULL); /* unsigned *thrdaddr */
72 #endif
73 if (*thread == NULL) return 1;
74 SetThreadPriority(*thread, THREAD_PRIORITY_ABOVE_NORMAL);
75 return 0;
76 }
77
pthread_join(pthread_t thread,void ** value_ptr)78 static INLINE int pthread_join(pthread_t thread, void **value_ptr) {
79 (void)value_ptr;
80 return (WaitForSingleObjectEx(thread, INFINITE, FALSE /*bAlertable*/) !=
81 WAIT_OBJECT_0 ||
82 CloseHandle(thread) == 0);
83 }
84
85 // Mutex
pthread_mutex_init(pthread_mutex_t * const mutex,void * mutexattr)86 static INLINE int pthread_mutex_init(pthread_mutex_t *const mutex,
87 void *mutexattr) {
88 (void)mutexattr;
89 InitializeCriticalSectionEx(mutex, 0 /*dwSpinCount*/, 0 /*Flags*/);
90 return 0;
91 }
92
pthread_mutex_trylock(pthread_mutex_t * const mutex)93 static INLINE int pthread_mutex_trylock(pthread_mutex_t *const mutex) {
94 return TryEnterCriticalSection(mutex) ? 0 : EBUSY;
95 }
96
pthread_mutex_lock(pthread_mutex_t * const mutex)97 static INLINE int pthread_mutex_lock(pthread_mutex_t *const mutex) {
98 EnterCriticalSection(mutex);
99 return 0;
100 }
101
pthread_mutex_unlock(pthread_mutex_t * const mutex)102 static INLINE int pthread_mutex_unlock(pthread_mutex_t *const mutex) {
103 LeaveCriticalSection(mutex);
104 return 0;
105 }
106
pthread_mutex_destroy(pthread_mutex_t * const mutex)107 static INLINE int pthread_mutex_destroy(pthread_mutex_t *const mutex) {
108 DeleteCriticalSection(mutex);
109 return 0;
110 }
111
112 // Condition
pthread_cond_destroy(pthread_cond_t * const condition)113 static INLINE int pthread_cond_destroy(pthread_cond_t *const condition) {
114 (void)condition;
115 return 0;
116 }
117
pthread_cond_init(pthread_cond_t * const condition,void * cond_attr)118 static INLINE int pthread_cond_init(pthread_cond_t *const condition,
119 void *cond_attr) {
120 (void)cond_attr;
121 InitializeConditionVariable(condition);
122 return 0;
123 }
124
pthread_cond_signal(pthread_cond_t * const condition)125 static INLINE int pthread_cond_signal(pthread_cond_t *const condition) {
126 WakeConditionVariable(condition);
127 return 0;
128 }
129
pthread_cond_broadcast(pthread_cond_t * const condition)130 static INLINE int pthread_cond_broadcast(pthread_cond_t *const condition) {
131 WakeAllConditionVariable(condition);
132 return 0;
133 }
134
pthread_cond_wait(pthread_cond_t * const condition,pthread_mutex_t * const mutex)135 static INLINE int pthread_cond_wait(pthread_cond_t *const condition,
136 pthread_mutex_t *const mutex) {
137 int ok;
138 ok = SleepConditionVariableCS(condition, mutex, INFINITE);
139 return !ok;
140 }
141 #elif defined(__OS2__)
142 #define INCL_DOS
143 #include <os2.h> // NOLINT
144
145 #include <errno.h> // NOLINT
146 #include <stdlib.h> // NOLINT
147 #include <sys/builtin.h> // NOLINT
148
149 #define pthread_t TID
150 #define pthread_mutex_t HMTX
151
152 typedef struct {
153 HEV event_sem_;
154 HEV ack_sem_;
155 volatile unsigned wait_count_;
156 } pthread_cond_t;
157
158 //------------------------------------------------------------------------------
159 // simplistic pthread emulation layer
160
161 #define THREADFN void *
162 #define THREAD_RETURN(val) (val)
163
164 typedef struct {
165 void *(*start_)(void *);
166 void *arg_;
167 } thread_arg;
168
169 static void thread_start(void *arg) {
170 thread_arg targ = *(thread_arg *)arg;
171 free(arg);
172
173 targ.start_(targ.arg_);
174 }
175
176 static INLINE int pthread_create(pthread_t *const thread, const void *attr,
177 void *(*start)(void *), void *arg) {
178 int tid;
179 thread_arg *targ = (thread_arg *)malloc(sizeof(*targ));
180 if (targ == NULL) return 1;
181
182 (void)attr;
183
184 targ->start_ = start;
185 targ->arg_ = arg;
186 tid = (pthread_t)_beginthread(thread_start, NULL, 1024 * 1024, targ);
187 if (tid == -1) {
188 free(targ);
189 return 1;
190 }
191
192 *thread = tid;
193 return 0;
194 }
195
196 static INLINE int pthread_join(pthread_t thread, void **value_ptr) {
197 (void)value_ptr;
198 return DosWaitThread(&thread, DCWW_WAIT) != 0;
199 }
200
201 // Mutex
202 static INLINE int pthread_mutex_init(pthread_mutex_t *const mutex,
203 void *mutexattr) {
204 (void)mutexattr;
205 return DosCreateMutexSem(NULL, mutex, 0, FALSE) != 0;
206 }
207
208 static INLINE int pthread_mutex_trylock(pthread_mutex_t *const mutex) {
209 return DosRequestMutexSem(*mutex, SEM_IMMEDIATE_RETURN) == 0 ? 0 : EBUSY;
210 }
211
212 static INLINE int pthread_mutex_lock(pthread_mutex_t *const mutex) {
213 return DosRequestMutexSem(*mutex, SEM_INDEFINITE_WAIT) != 0;
214 }
215
216 static INLINE int pthread_mutex_unlock(pthread_mutex_t *const mutex) {
217 return DosReleaseMutexSem(*mutex) != 0;
218 }
219
220 static INLINE int pthread_mutex_destroy(pthread_mutex_t *const mutex) {
221 return DosCloseMutexSem(*mutex) != 0;
222 }
223
224 // Condition
225 static INLINE int pthread_cond_destroy(pthread_cond_t *const condition) {
226 int ok = 1;
227 ok &= DosCloseEventSem(condition->event_sem_) == 0;
228 ok &= DosCloseEventSem(condition->ack_sem_) == 0;
229 return !ok;
230 }
231
232 static INLINE int pthread_cond_init(pthread_cond_t *const condition,
233 void *cond_attr) {
234 int ok = 1;
235 (void)cond_attr;
236
237 ok &=
238 DosCreateEventSem(NULL, &condition->event_sem_, DCE_POSTONE, FALSE) == 0;
239 ok &= DosCreateEventSem(NULL, &condition->ack_sem_, DCE_POSTONE, FALSE) == 0;
240 if (!ok) {
241 pthread_cond_destroy(condition);
242 return 1;
243 }
244 condition->wait_count_ = 0;
245 return 0;
246 }
247
248 static INLINE int pthread_cond_signal(pthread_cond_t *const condition) {
249 int ok = 1;
250
251 if (!__atomic_cmpxchg32(&condition->wait_count_, 0, 0)) {
252 ok &= DosPostEventSem(condition->event_sem_) == 0;
253 ok &= DosWaitEventSem(condition->ack_sem_, SEM_INDEFINITE_WAIT) == 0;
254 }
255
256 return !ok;
257 }
258
259 static INLINE int pthread_cond_broadcast(pthread_cond_t *const condition) {
260 int ok = 1;
261
262 while (!__atomic_cmpxchg32(&condition->wait_count_, 0, 0))
263 ok &= pthread_cond_signal(condition) == 0;
264
265 return !ok;
266 }
267
268 static INLINE int pthread_cond_wait(pthread_cond_t *const condition,
269 pthread_mutex_t *const mutex) {
270 int ok = 1;
271
272 __atomic_increment(&condition->wait_count_);
273
274 ok &= pthread_mutex_unlock(mutex) == 0;
275
276 ok &= DosWaitEventSem(condition->event_sem_, SEM_INDEFINITE_WAIT) == 0;
277
278 __atomic_decrement(&condition->wait_count_);
279
280 ok &= DosPostEventSem(condition->ack_sem_) == 0;
281
282 pthread_mutex_lock(mutex);
283
284 return !ok;
285 }
286 #else // _WIN32
287 #include <pthread.h> // NOLINT
288 #define THREADFN void *
289 #define THREAD_RETURN(val) val
290 #endif
291
292 #endif // CONFIG_MULTITHREAD
293
294 // State of the worker thread object
295 typedef enum {
296 NOT_OK = 0, // object is unusable
297 OK, // ready to work
298 WORK // busy finishing the current task
299 } AVxWorkerStatus;
300
301 // Function to be called by the worker thread. Takes two opaque pointers as
302 // arguments (data1 and data2). Should return true on success and return false
303 // in case of error.
304 typedef int (*AVxWorkerHook)(void *, void *);
305
306 // Platform-dependent implementation details for the worker.
307 typedef struct AVxWorkerImpl AVxWorkerImpl;
308
309 // Synchronization object used to launch job in the worker thread
310 typedef struct {
311 AVxWorkerImpl *impl_;
312 AVxWorkerStatus status_;
313 // Thread name for the debugger. If not NULL, must point to a string that
314 // outlives the worker thread. For portability, use a name <= 15 characters
315 // long (not including the terminating NUL character).
316 const char *thread_name;
317 AVxWorkerHook hook; // hook to call
318 void *data1; // first argument passed to 'hook'
319 void *data2; // second argument passed to 'hook'
320 int had_error; // true if a call to 'hook' returned false
321 } AVxWorker;
322
323 // The interface for all thread-worker related functions. All these functions
324 // must be implemented.
325 typedef struct {
326 // Must be called first, before any other method.
327 void (*init)(AVxWorker *const worker);
328 // Must be called to initialize the object and spawn the thread. Re-entrant.
329 // Will potentially launch the thread. Returns false in case of error.
330 int (*reset)(AVxWorker *const worker);
331 // Makes sure the previous work is finished. Returns true if worker->had_error
332 // was not set and no error condition was triggered by the working thread.
333 int (*sync)(AVxWorker *const worker);
334 // Triggers the thread to call hook() with data1 and data2 arguments. These
335 // hook/data1/data2 values can be changed at any time before calling this
336 // function, but not be changed afterward until the next call to Sync().
337 void (*launch)(AVxWorker *const worker);
338 // This function is similar to launch() except that it calls the
339 // hook directly instead of using a thread. Convenient to bypass the thread
340 // mechanism while still using the AVxWorker structs. sync() must
341 // still be called afterward (for error reporting).
342 void (*execute)(AVxWorker *const worker);
343 // Kill the thread and terminate the object. To use the object again, one
344 // must call reset() again.
345 void (*end)(AVxWorker *const worker);
346 } AVxWorkerInterface;
347
348 // Install a new set of threading functions, overriding the defaults. This
349 // should be done before any workers are started, i.e., before any encoding or
350 // decoding takes place. The contents of the interface struct are copied, it
351 // is safe to free the corresponding memory after this call. This function is
352 // not thread-safe. Return false in case of invalid pointer or methods.
353 int aom_set_worker_interface(const AVxWorkerInterface *const winterface);
354
355 // Retrieve the currently set thread worker interface.
356 const AVxWorkerInterface *aom_get_worker_interface(void);
357
358 //------------------------------------------------------------------------------
359
360 #ifdef __cplusplus
361 } // extern "C"
362 #endif
363
364 #endif // AOM_AOM_UTIL_AOM_THREAD_H_
365