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  vari-
       able 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 argu-
       ment 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 lt;Xavier.Leroy@inria.fr