call_once(3)		   Library Functions Manual		  call_once(3)

NAME
     call_once – call function only from a single thread, once

SYNOPSIS
     library “threads”
     #include <threads.h>

     once_flag once = ONCE_FLAG_INIT;

     void
     call_once(once_flag *flag, void (*fn)());

DESCRIPTION
     The call_once() function calls the given callback function fn exactly
     once even when called from multiple threads at the same time.  This is
     done by setting the given flag atomically upon entry to the function. The
     flag must be initialized to ONCE_FLAG_INIT before calling call_once().

HISTORY
     The call_once() function first appeared in the C11 standard ISO/IEC
     9899:2011.

AUTHORS
     Jan Adelsbach <jan@jadelsbach.de>

Linux 6.13.6-1-default					Linux 6.13.6-1-default