pthread_once(3POSIX)

NAME | SYNOPSIS | API RESTRICTIONS | DESCRIPTION | RETURN VALUE | ATTRIBUTES

NAME

pthread_once- initialize a library dynamically

SYNOPSIS

#include <pthread.h>
pthread_once_t once_control = PTHREAD_ONCE_INIT;

int pthread_once(pthread_once_t *once_control, void (*init_routine)void);

API RESTRICTIONS

The function or functions documented here may not be used safely in all application contexts with all APIs provided in the ChorusOS 5.0 product.

See API(5FEA) for details.

DESCRIPTION

The pthread_once() function is a synchronization tool used for dynamic initialization of library packages that are invoked concurrently from multiple threads. The first call to pthread_once() by any thread in an actor, with a once_control provided, will invoke the init_routine() function with no arguments. Subsequent calls to pthread_once() will not call init_routine(). On return from pthread_once(), it is guaranteed that init_routine() has completed. The variable referenced by the once_control argument is used to determine whether the associated initialization routine has been called.

If once_control has automatic storage duration or was not initialized using PTHREAD_ONCE_INIT, the behavior of pthread_once() is undefined.

RETURN VALUE

The pthread_once() function always returns zero.

ATTRIBUTES

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPE	ATTRIBUTE VALUE
Interface Stability	Evolving

NAME | SYNOPSIS | API RESTRICTIONS | DESCRIPTION | RETURN VALUE | ATTRIBUTES