threads.h File

The threads.h header file declares the following macros:

thread_local

Expands to _Thread_local.

ONCE_FLAG_INIT

Expands to a value that can be used to initialize an object of the type once_flag.

TSS_DTOR_ITERATIONS

Expands to an integer constant expression that represents the maximum number of times a destructor is called when a thread terminates.

The threads.h header file declares following types:

cnd_t

A complete object type that holds an identifier for a condition variable.

thrd_t

A complete object type that holds an identifier for a thread.

tss_t

A complete object type that holds an identifier for a thread-specific storage pointer.

mtx_t

A complete object type that holds an identifier for a mutex.

tss_dtor_t

A function pointer type void (*)(void*), used for a destructor for a thread-specific storage pointer.

thrd_start_t

A function pointer type int (*)(void*) that is passed to thrd_create to create a new thread.

once_flag

A complete object type that holds a flag for use by call_once.

The threads.h header file declares the following enumeration constants:

mtx_plain

The mtx_plain type is passed to mtx_init to create a mutex object that does not support timeout and test and returns.

mtx_recursive

The mtx_recursive type is passed to mtx_init to create a mutex object that supports recursive locking.

mtx_timed

The mtx_timed type is passed to mtx_init to create a mutex object that supports timeout.

thrd_timedout

The cnd_t type is returned by a timed wait function to indicate that the time specified in the call was reached without acquiring the requested resource.

thrd_success

The thrd_success type is returned by the function to indicate that the requested operation succeeded.

thrd_busy

The thrd_busy type is returned by the function to indicate that the requested operation failed because a resource requested by a test and return functions is already in use.

thrd_error

The thrd_error type is returned by a function to indicate that the requested operation failed.

thrd_nomem

The thrd_nomem type is returned by a function to indicate that the requested operation failed because it was unable to allocate memory.

The threads.h header file declares the following functions:

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);