On Tue, 9 Oct 2007, Roy Lyseng wrote:
Are increments atomic across SMP/multicore? It'd be hard to corrupt it, but
I don't know off the top of my head if it's safe to ignore locking when
you're just reading/writing to one set of 4-8bytes. I'll have to read up
(or hope someone who knows better about this use of memory barriers chimes
in. It's not something I deal with much outside of tracking down kernel
bugs on SMP systems).
Increments are generally not atomic. You have interfaces like
atomic_inc_ulong() in Solaris 10 and in the Linux kernel (AFAIK).
In Linux there's /usr/include/asm/atomic.h which has:
void atomic_inc(atomic_t *v)
Not sure if it's supported on every last platform, though.
-Todd
