> * Bruce Momjian <pgman@candle.pha.pa.us> [001116 14:02]:
> > > > This sounds like an interesting approach, yes.
> > > Question: Is sleep(0) guaranteed to at least give up control?
> > >
> > > The way I read my UnixWare 7's man page, it might not, since alarm(0)
> > > just cancels the alarm...
> >
> > Well, it certainly is a kernel call, and most OS's re-evaluate on kernel
> > call return.
> BUT, do we know for sure that sleep(0) is not optimized in the library
> to just return?
We can only do our best here. I think guessing whether other backends
are _about_ to commit is pretty shaky, and sleeping every time is a
waste. This seems the cleanest.
Funny you should mention the optimization. I just checked BSDI and saw:u_intsleep(secs) u_int secs;{ struct
timevalnt, ot; long diff; int rc; if (secs == 0) return (0);
So maybe we need another _fake_ kernel call, or a select/usleep with a
very small value.
-- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610)
853-3000+ If your life is a hard drive, | 830 Blythe Avenue + Christ can be your backup. | Drexel Hill,
Pennsylvania19026
