[PATCH] Avoid passing autotest job fds to test groups.

[Ralf Wildenhues]

* lib/autotest/general.m4 (AT_INIT) <Fifo job dispatcher>: Remove
commented closing of job output fd.  In serial test group driver,
ensure $at_jobs is set to 1, so other parts of Autotest can
reliably use this variable as indicator for parallel testing.
(AT_CLEANUP): Inside the subshell for the test group, close
AT_JOB_FIFO_IN_FD and AT_JOB_FIFO_OUT_FD if they are open.

Signed-off-by: Ralf Wildenhues <address@hidden>
---

* Eric Blake wrote on Wed, Jul 21, 2010 at 05:49:59AM CEST:
> Technically, the AT_CHECK commands only need worry about one fd;
> AT_JOB_FIFO_OUT_FD (in fact, my patch already clobbers AT_JOB_FIFO_IN_FD
> before the test is run),

For all but the first child.

> because that is the only fd that must still
> exist after the AT_CHECK has completed.

> Notice that we have this line:
> 
>        . "$at_test_source" [#] AT_JOB_FIFO_OUT_FD>&-

This, IIRC, is commented out because it is not portable to do such
redirections on '.' commands.

> At one point, we already thought about closing the fd only during the
> duration of the AT_CHECK, leaving it free for the AT_CHECK to use at
> will (and more importantly, so that AT_CHECK can't do 'echo >&7' to
> corrupt the state of the parallel test driver); it would just take
> un-commenting that line.
> 
> Additionally, it is not just AT_CHECK, but the entire
> AT_SETUP/AT_CLEANUP set that is run in a subshell.

Ah, good, so we should be able to close all open fds here (two for the
first child, one for the rest).

Something like this, which should also improve the case where --jobs=N
was passed but e.g., mkfifo didn't work out.

Cheers,
Ralf


 ChangeLog               |   10 ++++++++++
 lib/autotest/general.m4 |    9 ++++++++-
 2 files changed, 18 insertions(+), 1 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index e9146c3..09d7590 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2010-07-21  Ralf Wildenhues  <address@hidden>
+
+       Avoid passing autotest job fds to test groups.
+       * lib/autotest/general.m4 (AT_INIT) <Fifo job dispatcher>: Remove
+       commented closing of job output fd.  In serial test group driver,
+       ensure $at_jobs is set to 1, so other parts of Autotest can
+       reliably use this variable as indicator for parallel testing.
+       (AT_CLEANUP): Inside the subshell for the test group, close
+       AT_JOB_FIFO_IN_FD and AT_JOB_FIFO_OUT_FD if they are open.
+
 2010-07-20 Paul Eggert  <address@hidden>
        and Eric Blake  <address@hidden>
 
diff --git a/lib/autotest/general.m4 b/lib/autotest/general.m4
index f328ef4..fd89714 100644
--- a/lib/autotest/general.m4
+++ b/lib/autotest/general.m4
@@ -1405,7 +1405,7 @@ dnl           kill -13 $$
       at_fn_group_prepare
       if cd "$at_group_dir" &&
         at_fn_test $at_group &&
-        . "$at_test_source" [#] AT_JOB_FIFO_OUT_FD>&-
+        . "$at_test_source"
       then :; else
        AS_WARN([unable to parse test group: $at_group])
        at_failed=:
@@ -1440,6 +1440,7 @@ dnl           kill -13 $$
   wait
 else
   # Run serially, avoid forks and other potential surprises.
+  at_jobs=1
   for at_group in $at_groups; do
     at_fn_group_prepare
     if cd "$at_group_dir" &&
@@ -1913,6 +1914,12 @@ AT_xfail
 echo "#                             -*- compilation -*-" >> "$at_group_log"
 (
   AS_ECHO(["AT_ordinal. m4_defn([AT_line]): testing $at_desc ..."])
+  if test $at_jobs -ne 1; then
+    if $at_first; then
+      exec AT_JOB_FIFO_IN_FD>&-
+    fi
+    exec AT_JOB_FIFO_OUT_FD>&-
+  fi
   $at_traceon
 m4_undivert([TEST_SCRIPT])dnl Insert the code here
   set +x
-- 
1.7.2.rc3.47.g996ce