atomic.h File Reference

#include "config.h"

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Functions
int	avpriv_atomic_int_get (volatile int *ptr)
	Load the current value stored in an atomic integer.
void	avpriv_atomic_int_set (volatile int *ptr, int val)
	Store a new value in an atomic integer.
int	avpriv_atomic_int_add_and_fetch (volatile int *ptr, int inc)
	Add a value to an atomic integer.
void *	avpriv_atomic_ptr_cas (void *volatile *ptr, void *oldval, void *newval)
	Atomic pointer compare and swap.

Function Documentation

int avpriv_atomic_int_get

(

volatile int *

ptr

)

Load the current value stored in an atomic integer.

Parameters

ptr	atomic integer

Returns

the current value of the atomic integer

Note

This acts as a memory barrier.

Definition at line 75 of file atomic.c.

void avpriv_atomic_int_set	(	volatile int *	ptr,
		int	val
	)

Store a new value in an atomic integer.

Parameters

ptr	atomic integer
val	the value to store in the atomic integer

Note

This acts as a memory barrier.

Definition at line 80 of file atomic.c.

int avpriv_atomic_int_add_and_fetch	(	volatile int *	ptr,
		int	inc
	)

Add a value to an atomic integer.

Parameters

ptr	atomic integer
inc	the value to add to the atomic integer (may be negative)

Returns

the new value of the atomic integer.

Note

This does NOT act as a memory barrier. This is primarily intended for reference counting.

Definition at line 85 of file atomic.c.

void* avpriv_atomic_ptr_cas	(	void *volatile *	ptr,
		void *	oldval,
		void *	newval
	)

Atomic pointer compare and swap.

Parameters

ptr	pointer to the pointer to operate on
oldval	do the swap if the current value of *ptr equals to oldval
newval	value to replace *ptr with

Returns

the value of *ptr before comparison

Definition at line 91 of file atomic.c.