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* C11 <threads.h> emulation library
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* (C) Copyright yohhoy 2012.
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* Distributed under the Boost Software License, Version 1.0.
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* Permission is hereby granted, free of charge, to any person or organization
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* obtaining a copy of the software and accompanying documentation covered by
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* this license (the "Software") to use, reproduce, display, distribute,
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* execute, and transmit the Software, and to prepare [[derivative work]]s of the
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* Software, and to permit third-parties to whom the Software is furnished to
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* do so, all subject to the following:
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* The copyright notices in the Software and this entire statement, including
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* the above license grant, this restriction and the following disclaimer,
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* must be included in all copies of the Software, in whole or in part, and
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* all derivative works of the Software, unless such copies or derivative
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* works are solely in the form of machine-executable object code generated by
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* a source language processor.
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
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* SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
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* FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
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* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
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* DEALINGS IN THE SOFTWARE.
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#include <stdint.h> /* for intptr_t */
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EMULATED_THREADS_USE_NATIVE_TIMEDLOCK
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Use pthread_mutex_timedlock() for `mtx_timedlock()'
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Otherwise use mtx_trylock() + *busy loop* emulation.
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#if !defined(__CYGWIN__) && !defined(__APPLE__) && !defined(__NetBSD__)
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#define EMULATED_THREADS_USE_NATIVE_TIMEDLOCK
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/*---------------------------- macros ----------------------------*/
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#define ONCE_FLAG_INIT PTHREAD_ONCE_INIT
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#ifdef INIT_ONCE_STATIC_INIT
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#define TSS_DTOR_ITERATIONS PTHREAD_DESTRUCTOR_ITERATIONS
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#define TSS_DTOR_ITERATIONS 1 // assume TSS dtor MAY be called at least once.
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// FIXME: temporary non-standard hack to ease transition
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#define _MTX_INITIALIZER_NP PTHREAD_MUTEX_INITIALIZER
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/*---------------------------- types ----------------------------*/
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typedef pthread_cond_t cnd_t;
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typedef pthread_t thrd_t;
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typedef pthread_key_t tss_t;
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typedef pthread_mutex_t mtx_t;
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typedef pthread_once_t once_flag;
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Implementation limits:
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- Conditionally emulation for "mutex with timeout"
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(see EMULATED_THREADS_USE_NATIVE_TIMEDLOCK macro)
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struct impl_thrd_param {
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impl_thrd_routine(void *p)
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struct impl_thrd_param pack = *((struct impl_thrd_param *)p);
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return (void*)(intptr_t)pack.func(pack.arg);
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/*--------------- 7.25.2 Initialization functions ---------------*/
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call_once(once_flag *flag, void (*func)(void))
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pthread_once(flag, func);
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/*------------- 7.25.3 Condition variable functions -------------*/
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cnd_broadcast(cnd_t *cond)
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assert(cond != NULL);
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return (pthread_cond_broadcast(cond) == 0) ? thrd_success : thrd_error;
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cnd_destroy(cnd_t *cond)
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pthread_cond_destroy(cond);
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cnd_init(cnd_t *cond)
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assert(cond != NULL);
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return (pthread_cond_init(cond, NULL) == 0) ? thrd_success : thrd_error;
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cnd_signal(cnd_t *cond)
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assert(cond != NULL);
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return (pthread_cond_signal(cond) == 0) ? thrd_success : thrd_error;
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cnd_timedwait(cnd_t *cond, mtx_t *mtx, const struct timespec *abs_time)
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assert(cond != NULL);
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assert(abs_time != NULL);
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rt = pthread_cond_timedwait(cond, mtx, abs_time);
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return thrd_timedout;
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return (rt == 0) ? thrd_success : thrd_error;
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cnd_wait(cnd_t *cond, mtx_t *mtx)
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assert(cond != NULL);
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return (pthread_cond_wait(cond, mtx) == 0) ? thrd_success : thrd_error;
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/*-------------------- 7.25.4 Mutex functions --------------------*/
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mtx_destroy(mtx_t *mtx)
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pthread_mutex_destroy(mtx);
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* XXX: Workaround when building with -O0 and without pthreads link.
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* In such cases constant folding and dead code elimination won't be
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* available, thus the compiler will always add the pthread_mutexattr*
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* functions into the binary. As we try to link, we'll fail as the
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* symbols are unresolved.
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* Ideally we'll enable the optimisations locally, yet that does not
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* So the alternative workaround is to annotate the symbols as weak.
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* Thus the linker will be happy and things don't clash when building
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* with -O1 or greater.
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#if defined(HAVE_FUNC_ATTRIBUTE_WEAK) && !defined(__CYGWIN__)
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__attribute__((weak))
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int pthread_mutexattr_init(pthread_mutexattr_t *attr);
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__attribute__((weak))
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int pthread_mutexattr_settype(pthread_mutexattr_t *attr, int type);
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__attribute__((weak))
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int pthread_mutexattr_destroy(pthread_mutexattr_t *attr);
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mtx_init(mtx_t *mtx, int type)
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pthread_mutexattr_t attr;
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if (type != mtx_plain && type != mtx_timed && type != mtx_try
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&& type != (mtx_plain|mtx_recursive)
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&& type != (mtx_timed|mtx_recursive)
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&& type != (mtx_try|mtx_recursive))
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if ((type & mtx_recursive) == 0) {
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pthread_mutex_init(mtx, NULL);
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pthread_mutexattr_init(&attr);
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pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
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pthread_mutex_init(mtx, &attr);
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pthread_mutexattr_destroy(&attr);
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return (pthread_mutex_lock(mtx) == 0) ? thrd_success : thrd_error;
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mtx_trylock(mtx_t *mtx);
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mtx_timedlock(mtx_t *mtx, const struct timespec *ts)
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#ifdef EMULATED_THREADS_USE_NATIVE_TIMEDLOCK
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rt = pthread_mutex_timedlock(mtx, ts);
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return (rt == ETIMEDOUT) ? thrd_timedout : thrd_error;
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time_t expire = time(NULL);
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expire += ts->tv_sec;
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while (mtx_trylock(mtx) != thrd_success) {
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time_t now = time(NULL);
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return thrd_timedout;
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mtx_trylock(mtx_t *mtx)
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return (pthread_mutex_trylock(mtx) == 0) ? thrd_success : thrd_busy;
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mtx_unlock(mtx_t *mtx)
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return (pthread_mutex_unlock(mtx) == 0) ? thrd_success : thrd_error;
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/*------------------- 7.25.5 Thread functions -------------------*/
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thrd_create(thrd_t *thr, thrd_start_t func, void *arg)
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struct impl_thrd_param *pack;
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pack = (struct impl_thrd_param *)malloc(sizeof(struct impl_thrd_param));
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if (!pack) return thrd_nomem;
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if (pthread_create(thr, NULL, impl_thrd_routine, pack) != 0) {
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return pthread_self();
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thrd_detach(thrd_t thr)
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return (pthread_detach(thr) == 0) ? thrd_success : thrd_error;
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thrd_equal(thrd_t thr0, thrd_t thr1)
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return pthread_equal(thr0, thr1);
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pthread_exit((void*)(intptr_t)res);
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thrd_join(thrd_t thr, int *res)
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if (pthread_join(thr, &code) != 0)
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*res = (int)(intptr_t)code;
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thrd_sleep(const struct timespec *time_point, struct timespec *remaining)
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assert(time_point != NULL);
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nanosleep(time_point, remaining);
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/*----------- 7.25.6 Thread-specific storage functions -----------*/
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tss_create(tss_t *key, tss_dtor_t dtor)
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return (pthread_key_create(key, dtor) == 0) ? thrd_success : thrd_error;
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tss_delete(tss_t key)
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pthread_key_delete(key);
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return pthread_getspecific(key);
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tss_set(tss_t key, void *val)
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return (pthread_setspecific(key, val) == 0) ? thrd_success : thrd_error;
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/*-------------------- 7.25.7 Time functions --------------------*/
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#ifndef HAVE_TIMESPEC_GET
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timespec_get(struct timespec *ts, int base)
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if (base == TIME_UTC) {
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clock_gettime(CLOCK_REALTIME, ts);