pthread_once(3)

NAME

pthread_once - once-only initialization

SYNOPSIS

#include <pthread.h>
pthread_once_t once_control = PTHREAD_ONCE_INIT;
int  pthread_once(pthread_once_t  *once_control,  void  (*init_routine)
(void));

DESCRIPTION

The purpose of pthread_once is to ensure that a piece of initialization code is executed at most once. The once_control argument points to a static or extern variable statically initialized to PTHREAD_ONCE_INIT.

The first time pthread_once is called with a given once_control argument, it calls init_routine with no argument and changes the value of the once_control variable to record that initialization has been performed. Subsequent calls to pthread_once with the same once_control argument do nothing.

RETURN VALUE

pthread_once always returns 0.

ERRORS

None.

AUTHOR

Xavier Leroy <Xavier.Leroy@inria.fr>

LinuxThreads PTHREAD_ONCE(3)