Standard library header <threads.h> (C11)

 

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Symbol index

 

Standard Library headers

<assert.h> <complex.h> (C99) <ctype.h> <errno.h> <fenv.h> (C99) <float.h> <inttypes.h> (C99)     <iso646.h> (C95) <limits.h> <locale.h> <math.h>

<setjmp.h> <signal.h> <stdalign.h> (C11*) <stdarg.h> <stdatomic.h> (C11)     <stdbit.h> (C23) <stdbool.h> (C99*) <stdckdint.h> (C23) <stddef.h> <stdint.h> (C99) <stdio.h>

<stdlib.h> <stdmchar.h> (C29) <stdnoreturn.h> (C11*) <string.h> <tgmath.h> (C99) <threads.h> (C11) <time.h> <uchar.h> (C11) <wchar.h> (C95) <wctype.h> (C95)

 

This header is part of concurrency support library and provides support for threads, mutual exclusion, condition variables, and thread-specific storages.

Threads

thrd_t	implementation-defined complete object type identifying a thread
thrd_create (C11)	creates a thread (function)
thrd_equal (C11)	checks if two identifiers refer to the same thread (function)
thrd_current (C11)	obtains the current thread identifier (function)
thrd_sleep (C11)	suspends execution of the calling thread for the given period of time (function)
thrd_yield (C11)	yields the current time slice (function)
thrd_exit (C11)	terminates the calling thread (function)
thrd_detach (C11)	detaches a thread (function)
thrd_join (C11)	blocks until a thread terminates (function)
thrd_successthrd_timedoutthrd_busythrd_nomemthrd_error (C11)	indicates a thread error status (constant)
thrd_start_t (C11)	a typedef of the function pointer type int(*)(void*), used by thrd_create (typedef)

Mutual exclusion

mtx_t	mutex identifier
mtx_init (C11)	creates a mutex (function)
mtx_lock (C11)	blocks until locks a mutex (function)
mtx_timedlock (C11)	blocks until locks a mutex or times out (function)
mtx_trylock (C11)	locks a mutex or returns without blocking if already locked (function)
mtx_unlock (C11)	unlocks a mutex (function)
mtx_destroy (C11)	destroys a mutex (function)
mtx_plainmtx_recursivemtx_timed (C11)(C11)(C11)	defines the type of a mutex (enum)
Call once
call_once (C11)	calls a function exactly once (function)

Condition variables

cnd_t	condition variable identifier
cnd_init (C11)	creates a condition variable (function)
cnd_signal (C11)	unblocks one thread blocked on a condition variable (function)
cnd_broadcast (C11)	unblocks all threads blocked on a condition variable (function)
cnd_wait (C11)	blocks on a condition variable (function)
cnd_timedwait (C11)	blocks on a condition variable, with a timeout (function)
cnd_destroy (C11)	destroys a condition variable (function)

Thread-local storage

thread_local (C11)(removed in C23)	convenience macro for storage-class specifier _Thread_local (keyword macro)
tss_t	thread-specific storage pointer
TSS_DTOR_ITERATIONS (C11)	maximum number of times destructors are called (macro constant)
tss_dtor_t (C11)	function pointer type void(*)(void*), used for TSS destructor (typedef)
tss_create (C11)	creates thread-specific storage pointer with a given destructor (function)
tss_get (C11)	reads from thread-specific storage (function)
tss_set (C11)	write to thread-specific storage (function)
tss_delete (C11)	releases the resources held by a given thread-specific pointer (function)

Synopsis

#define __STDC_NO_THREADS__ 202311L
 
#define ONCE_FLAG_INIT      /* see description */
#define TSS_DTOR_ITERATIONS /* see description */
 
typedef /* see description */ cnd_t;
typedef /* see description */ thrd_t;
typedef /* see description */ tss_t;
typedef /* see description */ mtx_t;
typedef /* see description */ tss_dtor_t;
typedef /* see description */ thrd_start_t;
 
#define mtx_plain     /* see description */
#define mtx_recursive /* see description */
#define mtx_timed     /* see description */
#define once_flag     /* see description */
#define thrd_busy     /* see description */
#define thrd_error    /* see description */
#define thrd_nomem    /* see description */
#define thrd_success  /* see description */
#define thrd_timedout /* see description */
 
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, thrd_start_t func, 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, tss_dtor_t dtor);
void tss_delete(tss_t key);
void* tss_get(tss_t key);
int tss_set(tss_t key, void* val);