On Wed, Aug 05, 2015 at 08:41:44AM -0700, Junio C Hamano wrote:
> Interesting. This seems to break test under prove.
>
> cd t && make T=t4153-am-resume-override-opts.sh prove
>
> does not seem to return.
The new test-terminal.perl code is the culprit. It seems that if our
wrapped process terminates before our stdin-writing fork does, our
stdin-writing process will stall. I think this occurs with prove because
prove waits until all of its child processes terminate before returning.
So, the solution may be to send a SIGTERM to our stdin-writing fork
should our wrapped process terminate before it does, in order to ensure
that it immediately exits.
The following squash fixes it for me.
Thanks,
Paul
-- >8 --
Subject: [PATCH] squash! test_terminal: redirect child process' stdin to a pty
When the child process terminates before the copy_stdio() finishes
writing all of its data to the child's stdin slave pty, it will stall.
As such, we first move the stdin-pty-writing logic out of copy_stdio()
into its own subroutine copy_stdin() so that we can manage the forked
process ourselves, and then we send SIGTERM to the forked process should
the command we are wrapping terminate before copy_stdin() finishes
writing all of its data to un-stall it.
Signed-off-by: Paul Tan <pyokagan@xxxxxxxxx>
---
t/test-terminal.perl | 27 ++++++++++++++++++---------
1 file changed, 18 insertions(+), 9 deletions(-)
diff --git a/t/test-terminal.perl b/t/test-terminal.perl
index f6fc9ae..96b6a03 100755
--- a/t/test-terminal.perl
+++ b/t/test-terminal.perl
@@ -51,24 +51,26 @@ sub xsendfile {
copy($in, $out, 4096) or $!{EIO} or die "cannot copy from child: $!";
}
-sub copy_stdio {
- my ($in, $out, $err) = @_;
+sub copy_stdin {
+ my ($in) = @_;
my $pid = fork;
if (!$pid) {
- close($out);
- close($err);
xsendfile($in, \*STDIN);
exit 0;
}
- $pid = fork;
+ close($in);
+ return $pid;
+}
+
+sub copy_stdio {
+ my ($out, $err) = @_;
+ my $pid = fork;
defined $pid or die "fork failed: $!";
if (!$pid) {
- close($in);
close($out);
xsendfile(\*STDERR, $err);
exit 0;
}
- close($in);
close($err);
xsendfile(\*STDOUT, $out);
finish_child($pid) == 0
@@ -91,5 +93,12 @@ my $pid = start_child(\@ARGV, $master_in->slave, $master_out->slave, $master_err
close $master_in->slave;
close $master_out->slave;
close $master_err->slave;
-copy_stdio($master_in, $master_out, $master_err);
-exit(finish_child($pid));
+my $in_pid = copy_stdin($master_in);
+copy_stdio($master_out, $master_err);
+my $ret = finish_child($pid);
+# If the child process terminates before our copy_stdin() process is able to
+# write all of its data to $master_in, the copy_stdin() process could stall.
+# Send SIGTERM to it to ensure it terminates.
+kill 'TERM', $in_pid;
+finish_child($in_pid);
+exit($ret);
--
2.5.0.282.gdd6b4b0
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