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mtx_trylock(3) [freebsd man page]

THRD_CREATE(3)						   BSD Library Functions Manual 					    THRD_CREATE(3)

NAME
call_once, cnd_broadcast, cnd_destroy, cnd_init, cnd_signal, cnd_timedwait, cnd_wait, mtx_destroy, mtx_init, mtx_lock, mtx_timedlock, mtx_trylock, mtx_unlock, thrd_create, thrd_current, thrd_detach, thrd_equal, thrd_exit, thrd_join, thrd_sleep, thrd_yield, tss_create, tss_delete, tss_get, tss_set -- C11 threads interface LIBRARY
library ``libstdthreads'' SYNOPSIS
#include <threads.h> void call_once(once_flag *flag, void (*func)(void)); int cnd_broadcast(cnd_t *cond); void cnd_destroy(cnd_t *cond); int cnd_init(cnd_t *cond); int cnd_signal(cnd_t *cond); int cnd_timedwait(cnd_t * restrict cond, mtx_t * restrict mtx, const struct timespec * restrict ts); int cnd_wait(cnd_t *cond, mtx_t *mtx); void mtx_destroy(mtx_t *mtx); int mtx_init(mtx_t *mtx, int type); int mtx_lock(mtx_t *mtx); int mtx_timedlock(mtx_t * restrict mtx, const struct timespec * restrict ts); int mtx_trylock(mtx_t *mtx); int mtx_unlock(mtx_t *mtx); int thrd_create(thrd_t *thr, int (*func)(void *), void *arg); thrd_t thrd_current(void); int thrd_detach(thrd_t thr); int thrd_equal(thrd_t thr0, thrd_t thr1); _Noreturn void thrd_exit(int res); int thrd_join(thrd_t thr, int *res); int thrd_sleep(const struct timespec *duration, struct timespec *remaining); void thrd_yield(void); int tss_create(tss_t *key, void (*dtor)(void *)); void tss_delete(tss_t key); void * tss_get(tss_t key); int tss_set(tss_t key, void *val); DESCRIPTION
As of ISO/IEC 9899:2011 (``ISO C11''), the C standard includes an API for writing multithreaded applications. Since POSIX.1 already includes a threading API that is used by virtually any multithreaded application, the interface provided by the C standard can be considered superflu- ous. In this implementation, the threading interface is therefore implemented as a light-weight layer on top of existing interfaces. The func- tions to which these routines are mapped, are listed in the following table. Please refer to the documentation of the POSIX equivalent func- tions for more information. Function POSIX equivalent call_once() pthread_once(3) cnd_broadcast() pthread_cond_broadcast(3) cnd_destroy() pthread_cond_destroy(3) cnd_init() pthread_cond_init(3) cnd_signal() pthread_cond_signal(3) cnd_timedwait() pthread_cond_timedwait(3) cnd_wait() pthread_cond_wait(3) mtx_destroy() pthread_mutex_destroy(3) mtx_init() pthread_mutex_init(3) mtx_lock() pthread_mutex_lock(3) mtx_timedlock() pthread_mutex_timedlock(3) mtx_trylock() pthread_mutex_trylock(3) mtx_unlock() pthread_mutex_unlock(3) thrd_create() pthread_create(3) thrd_current() pthread_self(3) thrd_detach() pthread_detach(3) thrd_equal() pthread_equal(3) thrd_exit() pthread_exit(3) thrd_join() pthread_join(3) thrd_sleep() nanosleep(2) thrd_yield() pthread_yield(3) tss_create() pthread_key_create(3) tss_delete() pthread_key_delete(3) tss_get() pthread_getspecific(3) tss_set() pthread_setspecific(3) DIFFERENCES WITH POSIX EQUIVALENTS
The thrd_exit() function returns an integer value to the thread calling thrd_join(), whereas the pthread_exit() function uses a pointer. The mutex created by mtx_init() can be of type mtx_plain or mtx_timed to distinguish between a mutex that supports mtx_timedlock(). This type can be or'd with mtx_recursive to create a mutex that allows recursive acquisition. These properties are normally set using pthread_mutex_init()'s attr parameter. RETURN VALUES
If successful, the cnd_broadcast(), cnd_init(), cnd_signal(), cnd_timedwait(), cnd_wait(), mtx_init(), mtx_lock(), mtx_timedlock(), mtx_trylock(), mtx_unlock(), thrd_create(), thrd_detach(), thrd_equal(), thrd_join(), thrd_sleep(), tss_create() and tss_set() functions return thrd_success. Otherwise an error code will be returned to indicate the error. The thrd_current() function returns the thread ID of the calling thread. The tss_get() function returns the thread-specific data value associated with the given key. If no thread-specific data value is associated with key, then the value NULL is returned. ERRORS
The cnd_init() and thrd_create() functions will fail if: thrd_nomem The system has insufficient memory. The cnd_timedwait() and mtx_timedlock() functions will fail if: thrd_timedout The system time has reached or exceeded the time specified in ts before the operation could be completed. The mtx_trylock() function will fail if: thrd_busy The mutex is already locked. In all other cases, these functions may fail by returning general error code thrd_error. SEE ALSO
nanosleep(2), pthread(3) STANDARDS
These functions are expected to conform to ISO/IEC 9899:2011 (``ISO C11''). HISTORY
These functions appeared in FreeBSD 10.0. AUTHORS
Ed Schouten <ed@FreeBSD.org> BSD
December 26, 2011 BSD
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