On 02/11, Linus Torvalds wrote:
>
> @@ -2424,6 +2425,18 @@ wait_for (pid)
> sigaction (SIGCHLD, &oact, (struct sigaction *)NULL);
> sigprocmask (SIG_SETMASK, &chldset, (sigset_t *)NULL);
> # endif
> + /* If the waitchld returned EINTR, and the shell got a SIGINT,
> + then the child has not died yet, and we assume that the
> + child has blocked SIGINT. In that case, we require that the
> + child return with WSIGTERM() == SIGINT to actually consider
> + the ^C relevant. This is racy (the child may be in the
> + process of exiting and bash reacted to the EINTR first),
> + but this makes the race window much much smaller */
OK, I leave this up to you and Chet. At least the race is documented.
Another problem, child_blocked_sigint can be false positive if the
signal was sent to bash directly (not to pgrp). This means that the
next ^C won't work again.
And,
> + if (r == -1 && errno == EINTR && wait_sigint_received)
> + {
> + child_blocked_sigint = 1;
> + }
This can't work afaics. waitchld() can never return -1 && EINTR.
Perhaps waitchld() can set this flag, I don't know...
3087 /* If waitpid returns 0, there are running children. If it
returns -1,
3088 the only other error POSIX says it can return is EINTR. */
3089 CHECK_TERMSIG;
3090 if (pid <= 0)
3091 continue; /* jumps right to the test */
The code looks strange btw. "jumps right to the test" is correct, but
this code does
do {
...
} while ((sigchld || block == 0) && pid > (pid_t)0);
and this "continue" in fact means "break". So, perhaps, we can do
if (pid < 0) {
if (wait_sigint_received)
child_blocked_sigint = 1;
break;
}
Oleg.
