NAME
atomic_swap_uint,
atomic_swap_ulong,
atomic_swap_ptr —
atomic swap operations
SYNOPSIS
#include
<sys/atomic.h>
unsigned int
atomic_swap_uint(volatile
unsigned int *p, unsigned
int new);
unsigned long
atomic_swap_ulong(volatile
unsigned long *p,
unsigned long new);
void *
atomic_swap_ptr(volatile
void *p, void
*new);
DESCRIPTION
The atomic_swap set of functions provide an interface for atomically performing swap operations with respect to interrupts and multiple processors in the system.
The value referenced by the pointer p is replaced by the value new.
CONTEXT
atomic_swap_uint(),
atomic_swap_ulong(), and
atomic_swap_ptr() can all be called during autoconf,
from process context, or from interrupt context.
RETURN VALUES
These functions return the value at p as it was before the swap operation.
SEE ALSO
HISTORY
The atomic_swap functions first appeared in NetBSD 5.0 and OpenBSD 5.5.