periodically break out of idle mode to see if the connection to MPD is intact

it may be hanging if for example the local system was suspended. in
this situation mpd would detect the missing peer (us) when e.g. reporting
idle changes and close the tcp socket. later, the local system resumes
and the local tcp connection is still open and waiting for an idle result
forever

diff --git a/lib/App/MPD/Feeder.pm b/lib/App/MPD/Feeder.pm
index 7da421a6433bbcc0a8f805cc8d103306200c7c0a..2ce166f6a4b45e1a4a5534534af2a474eafe2bd9 100644 (file)
--- a/lib/App/MPD/Feeder.pm
+++ b/lib/App/MPD/Feeder.pm
@@ -11,6 +11,7 @@ use DBD::Pg;
 use DBI;
 use Getopt::Long;
 use IO::Async::Signal;
+use IO::Async::Timer::Periodic;
 use Log::Any qw($log);
 use Net::Async::MPD;
 use Object::Pad;
@@ -23,6 +24,7 @@ class App::MPD::Feeder {
     has $db :reader;
     has $db_needs_update :writer = 1;
     has $mpd :reader;
+    has $idler;
 
 use constant DEFAULT_CONFIG_FILE => '/etc/mpd-feeder/mpd-feeder.conf';
 
@@ -233,7 +235,7 @@ use constant DEFAULT_CONFIG_FILE => '/etc/mpd-feeder/mpd-feeder.conf';
 
     method prepare_to_wait_idle {
         $log->trace('declaring idle mode');
-        $mpd->send('idle database playlist')->on_done(
+        $idler = $mpd->send('idle database playlist')->on_done(
             sub {
                 my $result = shift;
 
@@ -273,6 +275,20 @@ use constant DEFAULT_CONFIG_FILE => '/etc/mpd-feeder/mpd-feeder.conf';
         $self->connect_mpd;
         $self->connect_db;
 
+        $mpd->loop->add(
+            IO::Async::Timer::Periodic->new(
+                interval => 300,
+                on_tick  => sub {
+                    if ($idler) {
+                        $log->trace('breaking idle to see if MPD is there');
+                        undef $idler;
+                        $log->trace("> noidle (direct)");
+                        $mpd->{mpd_handle}->write("noidle\n");
+                    }
+                },
+            )->start
+        );
+
         for ( ;; ) {
             $self->queue_songs( undef, sub { $self->prepare_to_wait_idle } );