2 * C11 <threads.h> emulation library
4 * (C) Copyright yohhoy 2012.
5 * Distributed under the Boost Software License, Version 1.0.
7 * Permission is hereby granted, free of charge, to any person or organization
8 * obtaining a copy of the software and accompanying documentation covered by
9 * this license (the "Software") to use, reproduce, display, distribute,
10 * execute, and transmit the Software, and to prepare [[derivative work]]s of the
11 * Software, and to permit third-parties to whom the Software is furnished to
12 * do so, all subject to the following:
14 * The copyright notices in the Software and this entire statement, including
15 * the above license grant, this restriction and the following disclaimer,
16 * must be included in all copies of the Software, in whole or in part, and
17 * all derivative works of the Software, unless such copies or derivative
18 * works are solely in the form of machine-executable object code generated by
19 * a source language processor.
21 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
22 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
23 * FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
24 * SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
25 * FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
26 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
27 * DEALINGS IN THE SOFTWARE.
37 #include <stdint.h> /* for intptr_t */
42 EMULATED_THREADS_USE_NATIVE_TIMEDLOCK
43 Use pthread_mutex_timedlock() for `mtx_timedlock()'
44 Otherwise use mtx_trylock() + *busy loop* emulation.
46 #if !defined(__CYGWIN__) && !defined(__APPLE__) && !defined(__NetBSD__)
47 #define EMULATED_THREADS_USE_NATIVE_TIMEDLOCK
53 /*---------------------------- macros ----------------------------*/
54 #define ONCE_FLAG_INIT PTHREAD_ONCE_INIT
55 #ifdef INIT_ONCE_STATIC_INIT
56 #define TSS_DTOR_ITERATIONS PTHREAD_DESTRUCTOR_ITERATIONS
58 #define TSS_DTOR_ITERATIONS 1 // assume TSS dtor MAY be called at least once.
61 // FIXME: temporary non-standard hack to ease transition
62 #define _MTX_INITIALIZER_NP PTHREAD_MUTEX_INITIALIZER
64 /*---------------------------- types ----------------------------*/
65 typedef pthread_cond_t cnd_t;
66 typedef pthread_t thrd_t;
67 typedef pthread_key_t tss_t;
68 typedef pthread_mutex_t mtx_t;
69 typedef pthread_once_t once_flag;
73 Implementation limits:
74 - Conditionally emulation for "mutex with timeout"
75 (see EMULATED_THREADS_USE_NATIVE_TIMEDLOCK macro)
77 struct impl_thrd_param {
83 impl_thrd_routine(void *p)
85 struct impl_thrd_param pack = *((struct impl_thrd_param *)p);
87 return (void*)(intptr_t)pack.func(pack.arg);
91 /*--------------- 7.25.2 Initialization functions ---------------*/
94 call_once(once_flag *flag, void (*func)(void))
96 pthread_once(flag, func);
100 /*------------- 7.25.3 Condition variable functions -------------*/
103 cnd_broadcast(cnd_t *cond)
105 assert(cond != NULL);
106 return (pthread_cond_broadcast(cond) == 0) ? thrd_success : thrd_error;
111 cnd_destroy(cnd_t *cond)
114 pthread_cond_destroy(cond);
119 cnd_init(cnd_t *cond)
121 assert(cond != NULL);
122 return (pthread_cond_init(cond, NULL) == 0) ? thrd_success : thrd_error;
127 cnd_signal(cnd_t *cond)
129 assert(cond != NULL);
130 return (pthread_cond_signal(cond) == 0) ? thrd_success : thrd_error;
135 cnd_timedwait(cnd_t *cond, mtx_t *mtx, const xtime *xt)
137 struct timespec abs_time;
141 assert(cond != NULL);
144 abs_time.tv_sec = xt->sec;
145 abs_time.tv_nsec = xt->nsec;
147 rt = pthread_cond_timedwait(cond, mtx, &abs_time);
150 return (rt == 0) ? thrd_success : thrd_error;
155 cnd_wait(cnd_t *cond, mtx_t *mtx)
158 assert(cond != NULL);
159 return (pthread_cond_wait(cond, mtx) == 0) ? thrd_success : thrd_error;
163 /*-------------------- 7.25.4 Mutex functions --------------------*/
166 mtx_destroy(mtx_t *mtx)
169 pthread_mutex_destroy(mtx);
173 * XXX: Workaround when building with -O0 and without pthreads link.
175 * In such cases constant folding and dead code elimination won't be
176 * available, thus the compiler will always add the pthread_mutexattr*
177 * functions into the binary. As we try to link, we'll fail as the
178 * symbols are unresolved.
180 * Ideally we'll enable the optimisations locally, yet that does not
183 * So the alternative workaround is to annotate the symbols as weak.
184 * Thus the linker will be happy and things don't clash when building
185 * with -O1 or greater.
187 #ifdef HAVE_FUNC_ATTRIBUTE_WEAK
188 __attribute__((weak))
189 int pthread_mutexattr_init(pthread_mutexattr_t *attr);
191 __attribute__((weak))
192 int pthread_mutexattr_settype(pthread_mutexattr_t *attr, int type);
194 __attribute__((weak))
195 int pthread_mutexattr_destroy(pthread_mutexattr_t *attr);
200 mtx_init(mtx_t *mtx, int type)
202 pthread_mutexattr_t attr;
204 if (type != mtx_plain && type != mtx_timed && type != mtx_try
205 && type != (mtx_plain|mtx_recursive)
206 && type != (mtx_timed|mtx_recursive)
207 && type != (mtx_try|mtx_recursive))
210 if ((type & mtx_recursive) == 0) {
211 pthread_mutex_init(mtx, NULL);
215 pthread_mutexattr_init(&attr);
216 pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
217 pthread_mutex_init(mtx, &attr);
218 pthread_mutexattr_destroy(&attr);
227 return (pthread_mutex_lock(mtx) == 0) ? thrd_success : thrd_error;
231 mtx_trylock(mtx_t *mtx);
238 mtx_timedlock(mtx_t *mtx, const xtime *xt)
244 #ifdef EMULATED_THREADS_USE_NATIVE_TIMEDLOCK
248 ts.tv_nsec = xt->nsec;
249 rt = pthread_mutex_timedlock(mtx, &ts);
252 return (rt == ETIMEDOUT) ? thrd_busy : thrd_error;
254 time_t expire = time(NULL);
256 while (mtx_trylock(mtx) != thrd_success) {
257 time_t now = time(NULL);
270 mtx_trylock(mtx_t *mtx)
273 return (pthread_mutex_trylock(mtx) == 0) ? thrd_success : thrd_busy;
278 mtx_unlock(mtx_t *mtx)
281 return (pthread_mutex_unlock(mtx) == 0) ? thrd_success : thrd_error;
285 /*------------------- 7.25.5 Thread functions -------------------*/
288 thrd_create(thrd_t *thr, thrd_start_t func, void *arg)
290 struct impl_thrd_param *pack;
292 pack = (struct impl_thrd_param *)malloc(sizeof(struct impl_thrd_param));
293 if (!pack) return thrd_nomem;
296 if (pthread_create(thr, NULL, impl_thrd_routine, pack) != 0) {
307 return pthread_self();
312 thrd_detach(thrd_t thr)
314 return (pthread_detach(thr) == 0) ? thrd_success : thrd_error;
319 thrd_equal(thrd_t thr0, thrd_t thr1)
321 return pthread_equal(thr0, thr1);
328 pthread_exit((void*)(intptr_t)res);
333 thrd_join(thrd_t thr, int *res)
336 if (pthread_join(thr, &code) != 0)
339 *res = (int)(intptr_t)code;
345 thrd_sleep(const xtime *xt)
349 req.tv_sec = xt->sec;
350 req.tv_nsec = xt->nsec;
351 nanosleep(&req, NULL);
362 /*----------- 7.25.6 Thread-specific storage functions -----------*/
365 tss_create(tss_t *key, tss_dtor_t dtor)
368 return (pthread_key_create(key, dtor) == 0) ? thrd_success : thrd_error;
373 tss_delete(tss_t key)
375 pthread_key_delete(key);
382 return pthread_getspecific(key);
387 tss_set(tss_t key, void *val)
389 return (pthread_setspecific(key, val) == 0) ? thrd_success : thrd_error;
393 /*-------------------- 7.25.7 Time functions --------------------*/
396 xtime_get(xtime *xt, int base)
399 if (base == TIME_UTC) {
400 xt->sec = time(NULL);