once.h File Reference

#include "base.h"

Go to the source code of this file.

Typedefs
typedef intptr_t	dispatch_once_t
	A predicate for use with dispatch_once().
Functions
DISPATCH_NONNULL_ALL DISPATCH_NOTHROW void	dispatch_once (dispatch_once_t *predicate, dispatch_block_t block)
	dispatch_once
DISPATCH_NONNULL1 DISPATCH_NONNULL3 DISPATCH_NOTHROW void	dispatch_once_f (dispatch_once_t *predicate, void *context, void(*function)(void *))

---

Typedef Documentation

dispatch_once_t

A predicate for use with dispatch_once().

It must be initialized to zero. Note: static and global variables default to zero.

Definition at line 38 of file once.h.

---

Function Documentation

DISPATCH_NONNULL_ALL DISPATCH_NOTHROW void dispatch_once	(	dispatch_once_t *	predicate,
		dispatch_block_t	block
	)

dispatch_once

Execute a block once and only once.

Parameters:

predicate	A pointer to a dispatch_once_t that is used to test whether the block has completed or not.
block	The block to execute once.

Always call dispatch_once() before using or testing any variables that are initialized by the block.

DISPATCH_NONNULL1 DISPATCH_NONNULL3 DISPATCH_NOTHROW void dispatch_once_f	(	dispatch_once_t *	predicate,
		void *	context,
		void(*)(void *)	function
	)