watch: retry signals to kill IDLE and polling processes

To ensure reliable signal delivery in Perl, it seems we need to
repeatedly signal processes which aren't using signalfd (or
EVFILT_SIGNAL) with our event loop.

1 files changed, 18 insertions, 9 deletions

diff --git a/lib/PublicInbox/WatchMaildir.pm b/lib/PublicInbox/WatchMaildir.pm
index e3df8515..23b2e9f1 100644
--- a/lib/PublicInbox/WatchMaildir.pm
+++ b/lib/PublicInbox/WatchMaildir.pm
@@ -202,18 +202,27 @@ sub _try_path {
         }
 }
 
+sub quit_done ($) {
+        my ($self) = @_;
+        return unless $self->{quit};
+
+        # don't have reliable wakeups, keep signalling
+        my $done = 1;
+        for (qw(idle_pids poll_pids)) {
+                my $pids = $self->{$_} or next;
+                for (keys %$pids) {
+                        $done = undef if kill('QUIT', $_);
+                }
+        }
+        $done;
+}
+
 sub quit {
         my ($self) = @_;
         $self->{quit} = 1;
         %{$self->{opendirs}} = ();
         _done_for_now($self);
-        if (my $imap_pid = $self->{-imap_pid}) {
-                kill('QUIT', $imap_pid);
-        }
-        for (qw(idle_pids poll_pids)) {
-                my $pids = $self->{$_} or next;
-                kill('QUIT', $_) for (keys %$pids);
-        }
+        quit_done($self);
         if (my $idle_mic = $self->{idle_mic}) {
                 eval { $idle_mic->done };
                 if ($@) {
@@ -921,8 +930,8 @@ sub watch {
                                                 [$self, $intvl, $urls]);
         }
         watch_fs_init($self) if $self->{mdre};
-        PublicInbox::DS->SetPostLoopCallback(sub {});
-        PublicInbox::DS->EventLoop until $self->{quit};
+        PublicInbox::DS->SetPostLoopCallback(sub { !$self->quit_done });
+        PublicInbox::DS->EventLoop;
         _done_for_now($self);
 }