Fix race condition in is_running when kill_whole_group is set

Martchus · Martchus · commit c4c79303145f · 2025-01-15T13:02:03.000+01:00
This fixes a bug introduced in ba7bb38 leading to `isotovideo can not be started` in openQA. We must not *only* check the process group because it might not have been created. (The `is_running` function might be called immediately after `start` when `setpgrp(0, 0)` hasn't been executed yet.) I tested this by putting `sleep 5` before `setpgrp(0, 0)`. Without this change openQA runs into `isotovideo can not be started` and with this change it works. I also tested whether cleanup of the whole process group still works. Related ticket: https://progress.opensuse.org/issues/170209
diff --git a/lib/Mojo/IOLoop/ReadWriteProcess.pm b/lib/Mojo/IOLoop/ReadWriteProcess.pm
@@ -404,7 +404,7 @@ sub is_running {
   my ($self) = shift;
   $self->session->consume_collected_info;
   return 0 unless my $pid = $self->process_id;
-  kill(0, ($self->kill_whole_group ? -$pid : $pid));
+  kill(0, ($self->kill_whole_group ? (-$pid, $pid) : ($pid)));
 }
 
 sub write_pidfile {

Original file line number	Diff line number	Diff line change
`@@ -404,7 +404,7 @@ sub is_running {`
`404`	`404`	`my ($self) = shift;`
`405`	`405`	`$self->session->consume_collected_info;`
`406`	`406`	`return 0 unless my $pid = $self->process_id;`
`407`		`- kill(0, ($self->kill_whole_group ? -$pid : $pid));`
	`407`	`+ kill(0, ($self->kill_whole_group ? (-$pid, $pid) : ($pid)));`
`408`	`408`	`}`
`409`	`409`
`410`	`410`	`sub write_pidfile {`