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ATOMIC_ADD_INT(9)        BSD Kernel Developer's Manual       ATOMIC_ADD_INT(9)

NAME
     atomic_add_int, atomic_add_int_nv, atomic_add_long, atomic_add_long_nv --
     atomic addition operations

SYNOPSIS
     #include <&lt;sys/atomic.h>&gt;

     void
     atomic_add_int(volatile unsigned int *p, unsigned int v);

     unsigned int
     atomic_add_int_nv(volatile unsigned int *p, unsigned int v);

     void
     atomic_add_long(volatile unsigned long *p, unsigned long v);

     unsigned long
     atomic_add_long_nv(volatile unsigned long *p, unsigned long v);

DESCRIPTION
     The atomic_add set of functions provide an interface for atomically per-
     forming add and add-and-fetch operations with respect to interrupts and
     multiple processors in the system.

     The value referenced by the pointer p is incremented by the value v.

CONTEXT
     atomic_add_int(), atomic_add_int_nv(), atomic_add_long(), and
     atomic_add_long_nv() can all be called during autoconf, from process con-
     text, or from interrupt context.

RETURN VALUES
     atomic_add_int and atomic_add_long perform the addition without returning
     any knowledge of the value at p.

     atomic_add_int_nv and atomic_add_long_nv return the value at p after the
     addition was performed.

SEE ALSO
     atomic_inc_int(9), atomic_sub_int(9)

HISTORY
     The atomic_add functions first appeared in NetBSD 5.0 and OpenBSD 5.5.

BSD                            February 13, 2014                           BSD