Dag-Erling Smorgrav <d...@flood.ping.uio.no> wrote: >Alfred Perlstein <bri...@rush.net> writes: >> specifically how you say you increment it, then decrement it, >> if you have multiple handlers where one can interupt another >> you can have the counter get jumbled. > >Not if increment / decrement is atomic.
Which it _isn't_ in general. The only case where it _is_ atomic is on a UP i386, where the compiler has generated an `inc' instruction (which it might not). Check out /sys/alpha/include/atomic.h or a recent (less than a week old [1]) -current version of /sys/i386/include/atomic.h for atomic code. Peter [1] It was broken prior to this. To Unsubscribe: send mail to majord...@freebsd.org with "unsubscribe freebsd-hackers" in the body of the message
