| PTHREAD_ONCE(3) | Library Functions Manual | PTHREAD_ONCE(3) |
pthread_once —
#include <pthread.h>
int
pthread_once(pthread_once_t
*once_control, void
(*init_routine)(void));
pthread_once_t once_control
=
PTHREAD_ONCE_INIT;
pthread_once() by any thread in a
process, with a given once_control, will call the
init_routine() with no arguments. Subsequent calls to
pthread_once() with the same
once_control will not call the
init_routine() On return from
pthread_once(), it is guaranteed that
init_routine() has completed. The
once_control parameter is used to determine whether the
associated initialization routine has been called.
The function pthread_once() is not a
cancellation point. However, if init_routine() is a
cancellation point and is cancelled, the effect on
once_control is as if
pthread_once() was never called.
The constant PTHREAD_ONCE_INIT initializes
the static once synchronization control structure
once_control to be used with
pthread_once(). The behavior of
pthread_once() is undefined if
once_control has automatic storage duration or is not
initialized by PTHREAD_ONCE_INIT.
pthread_once() function will return
zero. Otherwise an error number will be returned to indicate the error.
| July 9, 2010 | NetBSD 10.0 |