Refactor code with self._next()

src/bot.py

@@ -54,6 +54,12 @@ class Music(commands.Cog):
     # pylint: disable=no-member
     self._handle_playback.cancel()
 
+  def _next(self):
+    """Trigger playback of next song."""
+    self._queue.task_done()
+    if self._queue_lock.locked():
+      self._queue_lock.release()
+
   @tasks.loop()
   async def _handle_playback(self):
     while True:
@@ -64,16 +70,14 @@ class Music(commands.Cog):
           # Bot is no longer in a voice channel.
           # This could be the case because a stop command was issued.
           # We will skip this (and possibly all remaining songs) in the queue
-          self._queue.task_done()
-          self._queue_lock.release()
+          self._next()
           continue
         audio = discord.FFmpegPCMAudio(song.audio_url, **self._ffmpeg_options)
 
         def after(err):
           if err:
             print(f"Player error: {err}")
-          self._queue.task_done()
-          self._queue_lock.release()
+          self._next()
         ctx.voice_client.play(audio, after=after)
         embed = NowPlayingMessage(title=song.title, url=song.webpage_url)
         await ctx.send(embed=embed)
@@ -83,8 +87,7 @@ class Music(commands.Cog):
         if ctx:
           embed = ErrorMessage(str(err))
           await ctx.send(embed=embed)
-        self._queue.task_done()
-        self._queue_lock.release()
+        self._next()
 
   @_handle_playback.before_loop
   async def before_handle_playback(self):