Re: RT Sigio broken on 2.4.19-pre8

Dan Kegel (dank@kegel.com)
Mon, 27 May 2002 18:26:54 -0700


Dan Kegel wrote:
>
> Aaron Sethman wrote:
> > > > Using the Dan Kegel's Poller_bench utility I noticed that RT SIGIO is not
> > > > working on 2.4.19-pre8. Basically sigtimedwait() is always returning
> > > > SIGIO. Note that 2.4.18 works fine.
> > > > ... It seems rtsig-nr keeping rising slowly as the system runs.
>
> That sounds like the way I'm clearing the signal queue is not working.
> Here's a minimal test case for clearing the signal queue. Could
> you try it and tell me what it says?

Er, forgot to send the signal. Corrected test case:

#include <stdio.h>
#include <signal.h>
#include <assert.h>

int main(int argc, char **argv)
{
sigset_t sigset;
siginfo_t info;
static struct timespec timeout = {0,0};

// block delivery of SIGRTMIN
sigemptyset(&sigset);
sigaddset(&sigset, SIGRTMIN);
assert(0 == sigprocmask(SIG_BLOCK, &sigset, NULL));

raise(SIGRTMIN);

// clear signal queue
assert(0 == signal(SIGRTMIN, SIG_IGN)); // POSIX says this clears the queue

// Make sure that cleared the queue. (Note that timeout is zero here.)
assert(sigtimedwait(&sigset, &info, &timeout) != SIGRTMIN);

printf("test passed\n");
exit(0);
}
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