systemd.diff

diff --git a/lib/Mojo/Server/Hypnotoad.pm b/lib/Mojo/Server/Hypnotoad.pm
index 3a0af10..195d914 100644
--- a/lib/Mojo/Server/Hypnotoad.pm
+++ b/lib/Mojo/Server/Hypnotoad.pm
@@ -56,7 +56,7 @@ sub run {
   weaken $self;
   $prefork->on(wait   => sub { $self->_manage });
   $prefork->on(reap   => sub { $self->_cleanup(pop) });
-  $prefork->on(finish => sub { $self->{finished} = 1 });
+  $prefork->on(finish => sub { $self->_finish });
 
   # Testing
   _exit('Everything looks good!') if $ENV{HYPNOTOAD_TEST};
@@ -87,6 +87,16 @@ sub _cleanup {
 
 sub _exit { say shift and exit 0 }
 
+sub _finish {
+  my $self = shift;
+
+  $self->{finish} = 1;
+  return unless my $new = $self->{new};
+  my $prefork = $self->prefork->cleanup(0);
+  unlink $prefork->pid_file;
+  $prefork->ensure_pid_file($new);
+}
+
 sub _hot_deploy {
 
   # Make sure server is running
@@ -121,7 +131,7 @@ sub _manage {
     }
 
     # Timeout
-    kill 'KILL', $self->{new}
+    $prefork->cleanup(1) and kill 'KILL', $self->{new}
       if $self->{upgrade} + $self->upgrade_timeout <= steady_time;
   }
 }
diff --git a/lib/Mojo/Server/Prefork.pm b/lib/Mojo/Server/Prefork.pm
index 4ccac85..bd4ee7a 100644
--- a/lib/Mojo/Server/Prefork.pm
+++ b/lib/Mojo/Server/Prefork.pm
@@ -39,7 +39,7 @@ sub check_pid {
 }
 
 sub ensure_pid_file {
-  my $self = shift;
+  my ($self, $pid) = (shift, shift // $$);
 
   # Check if PID file already exists
   return if -e (my $file = $self->pid_file);
@@ -50,7 +50,7 @@ sub ensure_pid_file {
     unless open my $handle, '>', $file;
   $self->app->log->info(qq{Creating process id file "$file"});
   chmod 0644, $handle;
-  print $handle $$;
+  print $handle $pid;
 }
 
 sub healthy {
@@ -433,6 +433,7 @@ not running.
 =head2 ensure_pid_file
 
   $prefork->ensure_pid_file;
+  $prefork->ensure_pid_file($pid);
 
 Ensure L</"pid_file"> exists.