On 9/12/06, Gustavo Carneiro <[EMAIL PROTECTED]> wrote:
> On 9/12/06, Adam Olsen <[EMAIL PROTECTED]> wrote:
> > My previous mention of using a *single* flag may survive corruption
> > simply because we can tolerate false positives. Signal handlers would
> > write 0xFFFFFFFF, the poll loop would check if *any* bit is set. If
> > so, write 0x0, read off the fd, then loop around and check it again.
> > If the start of the read() acts as a write-barrier it SHOULD guarantee
> > we don't miss any positive writes.
> PyErr_CheckSignals()
> {
> if (signal_flag) {
> char signum;
> signal_flag = 0;
> while (read(signal_pipe_r, &signum, 1) == 1)
> process_signal(signum);
> }
> }
The more I think about this the less I like relying on read() imposing
a hardware write barrier. Unless somebody can say otherwise, I think
we'd be better of putting dummy
PyThread_aquire_lock/PyThread_release_lock calls in there.
--
Adam Olsen, aka Rhamphoryncus
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