Arve Knudsen <[EMAIL PROTECTED]> writes: > True .. That was one approach I considered originally while sketching > up solutions, I guess it slipped my mind in the meantime :| I was > thinking it could possibly be an expensive operation though as NPTL > sources seem to indicate, maybe best avoided if memory locks are > involved (I'm no optimization guru, I'm sure you can tell).
It doesn't look all that expensive. The magic is done by a platform- dependent compare-and-swap operation. On some SMP machines that can be slow, but generally only in high-contention situations (AFAIK). > Anyway, do you think it would be good to keep a canary around to act > on CPU starvation? Personally, I don't see much need for a canary thread. Others may disagree. But, a watchdog is quite helpful for debugging. In some cases, the application will provide its own watchdog. Is it possible for that thread to be optional? -- joq
