On Tue, Dec 9, 2008 at 8:10 PM, Anirban Sinha <[EMAIL PROTECTED]> wrote:
> There is yet another bug in Openntpd. This is direct copy-paste from
> openntpd code (ntpd.c:main()):
>
> do {
> if ((pid = wait(NULL)) == -1 &&
> errno != EINTR && errno != ECHILD)
> fatal("wait");
> } while (pid != -1 || (pid == -1 && errno == EINTR));
>
> What this code intends to do is to reap all children and move on when
> there are no more. Instead, it ends up blocking indefinitely even when
> there are no children to reap!
How is it blocking indefinitely? Is wait() not returning -1 with
errno == ECHILD when there are no children to reap? What led you to
the conclusion that this code was blocking? (What platform are you
running this on?)
> The way I fixed the bug is by doing this:
> + if (chld_pid && (pid = waitpid(chld_pid, &status, 0)) == -1 &&
> + errno != EINTR && errno != ECHILD)
> + fatal("wait");
> + if (pid !=-1)
> + log_info("child %d exited with return code %d",
> pid,WEXITSTATUS(status));
This code fails to retry the waitpid() if it returns with EINTR.
Philip Guenther
