Re: PATCH: job-control

[Sven Wischnowsky <wischnow@informatik.hu-berlin.de>]

Bart Schaefer wrote:

> ...
> 
> So now you're saying it works to do the child_unblock() *after* the
> waitjobs() rather than before?  That makes no sense; waitjobs() does
> a child_unblock() at the end.  So if the previous child_unblock()
> (inside the !STAT_LOCKED test) worked, then waitjobs() was getting
> called, and this child_unblock() shouldn't make any difference.

See 9498: it caused problems in a case where jobtab[thisjob] didn't
have any procs so that waitjobs() didn't call waitjob() -- and hence
no child_whatever().

> Unless this one is happening in a different call to execpline()?  Does
> the patch below work too?

No, because in that case we *were* calling waitjobs(), without any
effect, though.

> In any case, that last child_block() above should be outside the close
> brace.

Sorry, I had forgotten about that. Although it may be cleaner to put
it directly after the waitjobs() (and call it only if that was
called).

We could also enhance the test for the child{un,}block() to not call
them if we are sure that the waitjob() was called.

This patch instead of Bart's.

Bye
 Sven

diff -ru ../z.old/Src/exec.c Src/exec.c
--- ../z.old/Src/exec.c	Tue Feb  1 14:47:35 2000
+++ Src/exec.c	Wed Feb  2 09:20:29 2000
@@ -932,6 +932,7 @@
     } else {
 	if (newjob != lastwj) {
 	    Job jn = jobtab + newjob;
+	    int updated;
 
 	    if (newjob == list_pipe_job && list_pipe_child)
 		_exit(0);
@@ -980,10 +981,14 @@
 		    jn->stat |= STAT_NOPRINT;
 		    makerunning(jn);
 		}
-		if (!(jn->stat & STAT_LOCKED))
+		if (!(jn->stat & STAT_LOCKED)) {
+		    updated = !!jobtab[thisjob].procs;
 		    waitjobs();
-
-		if (list_pipe_job && jobtab[list_pipe_job].procs &&
+		    child_block();
+		} else
+		    updated = 0;
+		if (!updated &&
+		    list_pipe_job && jobtab[list_pipe_job].procs &&
 		    !(jobtab[list_pipe_job].stat & STAT_STOPPED)) {
 		    child_unblock();
 		    child_block();

--
Sven Wischnowsky                         wischnow@informatik.hu-berlin.de