Francois Gouget : testbot/Engine: Prevent recursion into ScheduleJobs().

[Alexandre Julliard]

Module: tools
Branch: master
Commit: 399c4bedd782326bba65b0944caeaf91df65a7ef
URL:    https://source.winehq.org/git/tools.git/?a=commit;h=399c4bedd782326bba65b094...

Author: Francois Gouget <fgouget(a)codeweavers.com>
Date:   Fri Jun 17 10:09:27 2022 +0200

testbot/Engine: Prevent recursion into ScheduleJobs().

Recursion may happen through the ScheduleJobs() -> VM::Run() ->
VMStatusChange() -> ScheduleJobs() chain.
It can cause multiple revert processes to run on the same VM, or even a
revert process to run at the same time as a task.

Signed-off-by: Francois Gouget <fgouget(a)codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard(a)winehq.org>

---

 testbot/lib/WineTestBot/Engine/Scheduler.pm | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/testbot/lib/WineTestBot/Engine/Scheduler.pm b/testbot/lib/WineTestBot/Engine/Scheduler.pm
index cc2ea1f1..1b21ab97 100644
--- a/testbot/lib/WineTestBot/Engine/Scheduler.pm
+++ b/testbot/lib/WineTestBot/Engine/Scheduler.pm
@@ -945,6 +945,7 @@ sub _PowerOffDirtyVMs($)
   }
 }
 
+my $_InScheduleJobs;
 my $_LastTaskCounts = "";
 
 =pod
@@ -1003,6 +1004,11 @@ kept on standby so they are ready when their turn comes.
 
 sub ScheduleJobs()
 {
+  # Don't let Engine notifications (specifically VMStatusChange) cause
+  # recursion into ScheduleJobs().
+  return if ($_InScheduleJobs);
+  $_InScheduleJobs = 1;
+
   my $Sched = _CheckAndClassifyVMs();
   my $NeededVMs = _ScheduleTasks($Sched);
   _RevertVMs($Sched, $NeededVMs);
@@ -1052,6 +1058,8 @@ sub ScheduleJobs()
     $Timeout = 600;
   }
   AddEvent("ScheduleJobs", $Timeout, 0, \&ScheduleJobs);
+
+  $_InScheduleJobs = undef;
 }