On Sat, 29 Sep 2001, Alfred Perlstein wrote:
> * Toshihiko ARAI <[EMAIL PROTECTED]> [010929 11:10] wrote:
> > I consider the following code of system(3). pid is changed by return
> > value of _wait4(). I feel this need a correction.
> >
> > default: /* parent */
> > do {
> > pid = _wait4(pid, &pstat, 0, (struct rusage *)0);
> > } while (pid == -1 && errno == EINTR);
> > break;
> >
> > Please review and commit this patch.
>
> Why does it need to be corrected? What sort of bad behaviour
> are you seeing? You do 'a' and you see 'b' when you should
> see 'c'.
>
> What's a, b and c?
> Well, hypothetically (I have no time to attempt to set something up to test this), it looks to me like: If you: 1. Fork, and create a child (say, pid 10) 2. Call system, which forks and creates a child (say, pid 11) 3. Make the child (pid 10) exit now. 3. Interrupt the call to _wait4(pid [=11], ...); You _should_ see nothing happen. i.e. system() would simply loop again until the other child exits. However, what I think you'd see is system() setting pid == -1, calling _wait4(-1, ...); and _wait4() returning 10, and system() returning whilst your child is still running happily away. If I run out of bugs to squash in ircd, I might try to produce this (I suppose reproduce is the wrong word, since no one has reported it in the first place...) -- David Taylor [EMAIL PROTECTED]
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