NAME

qb_atomic_pointer_compare_and_exchange - Compares oldval with the pointer pointed to by atomic and if they are equal, atomically exchanges *atomic with newval.

SYNOPSIS

#include <qb/qbatomic.h>

int32_t qb_atomic_pointer_compare_and_exchange(


    volatile void *QB_GNUC_MAY_ALIAS   *atomic,     /* a pointer to a void* */


    void                               *oldval,     /* the assumed old value of *atomic */


    void                               *newval     /* the new value of *atomic*/
);

PARAMS

atomic a pointer to a void*

oldval the assumed old value of *atomic

newval the new value of *atomic

DESCRIPTION

Also acts as a memory barrier.

RETURN VALUE

QB_TRUE if atomic was equal oldval, else QB_FALSE.

SEE ALSO

qb_atomic_int_set(3), qb_atomic_int_compare_and_exchange(3), qb_atomic_int_get(3), qb_atomic_int_add(3), qb_atomic_init(3), qb_atomic_pointer_get(3), qb_atomic_int_exchange_and_add(3), qb_atomic_pointer_set(3)

COPYRIGHT

Copyright (C) 2003 Sebastian Wilhelmi