PTHREAD_BARRIER(3) | Library Functions Manual | PTHREAD_BARRIER(3) |
pthread_barrier
,
pthread_barrier_init
,
pthread_barrier_destroy
,
pthread_barrier_wait
—
#include <pthread.h>
int
pthread_barrier_init
(pthread_barrier_t
* restrict barrier, const
pthread_barrierattr_t * restrict attr,
unsigned int count);
int
pthread_barrier_destroy
(pthread_barrier_t
*barrier);
int
pthread_barrier_wait
(pthread_barrier_t
*barrier);
pthread_barrier_init
() function creates a new
barrier with attributes attr and
count. The count parameter
indicates the number of threads which will participate in the barrier. The
pthread_barrierattr_init(3)
function may be used to specify the attributes supplied in
attr. If attr is
NULL
, the default attributes are used. Barriers are
most commonly used in the decomposition of parallel loops.
The pthread_barrier_destroy
() function
causes the resources allocated to barrier to be
released. No threads should be blocked on barrier.
The pthread_barrier_wait
() function causes
the current thread to wait on the barrier specified. Once as many threads as
specified by the count parameter to the corresponding
pthread_barrier_init
() call have called
pthread_barrier_wait
(), all threads will wake up,
return from their respective pthread_barrier_wait
()
calls and continue execution.
pthread_barrier_init
() will return zero
and put the new barrier id into barrier, otherwise an
error number will be returned to indicate the error.
If successful, pthread_barrier_destroy
()
will return zero. Otherwise an error value will be returned.
If successful, pthread_barrier_wait
() will
return zero for all waiting threads except for one. One thread will receive
status PTHREAD_BARRIER_SERIAL_THREAD
, which is
intended to indicate that this thread may be used to update shared data. It
is the responsibility of this thread to insure the visibility and atomicity
of any updates to shared data with respect to the other threads
participating in the barrier. In the case of failure, an error value will be
returned.
pthread_barrier_init
() function may fail if:
EINVAL
]The pthread_barrier_destroy
() function may
fail if:
EBUSY
]EINVAL
]The pthread_barrier_wait
() function may
fail if:
EINVAL
]October 22, 2017 | NetBSD 9.2 |