pthread_once(3P)

NAME
     pthread_once - thread-safe initialization

C SYNOPSIS
     #include <pthread.h>

     int pthread_once(pthread_once_t *once, void (*init)(void));

DESCRIPTION
     The pthread_once() function ensures that the function init is called
     exactly once for all callers using the once initialization variable.
     This variable is initialized with the constant PTHREAD_ONCE_INIT.  While
     init is being executed all callers of pthread_once() will wait.

     If a thread is cancelled while executing the init function [see
     pthread_setcancelstate()], then pthread_once() will permit another thread
     (possibly waiting) to make the call.

DIAGNOSTICS
     There are no errors for pthread_once.

SEE ALSO
     pthread_setcancelstate(3P).