Another attempt to keep Kodi from crashing on playback startup

default.py

@@ -157,17 +157,11 @@ class Main():
             # Handle -1 received, not waiting for main thread
             return
         # Wait for the result from the main PKC thread
-        result = transfer.wait_for_transfer()
+        result = transfer.wait_for_transfer(source='main')
-        if result is None:
+        if result is True:
-            LOG.error('Error encountered, aborting')
-            utils.dialog('notification',
-                         heading='{plex}',
-                         message=utils.lang(30128),
-                         icon='{error}',
-                         time=3000)
-            xbmcplugin.setResolvedUrl(HANDLE, False, xbmcgui.ListItem())
-        elif result is True:
             xbmcplugin.setResolvedUrl(HANDLE, False, xbmcgui.ListItem())
+            # Tell main thread that we're done
+            transfer.send(True, target='main')
         else:
             # Received a xbmcgui.ListItem()
             xbmcplugin.setResolvedUrl(HANDLE, True, result)

resources/lib/playback.py

@@ -177,10 +177,10 @@ def _playback_init(plex_id, plex_type, playqueue, pos):
             plex_type in v.PLEX_VIDEOTYPES and
             playqueue.kodi_pl.size() > 1):
         LOG.debug('Detected widget playback for videos')
-        # Need to clear playlist because playqueue.kodi_pl.size() could return
+        # playqueue.kodi_pl.size() could return more than one - since playback
-        # more than one - since playback was initiated from the audio queue!
+        # was initiated from the audio queue!
-        playqueue.clear()
+        pass
-    if playqueue.kodi_pl.size() > 1:
+    elif playqueue.kodi_pl.size() > 1:
         # Special case - we already got a filled Kodi playqueue
         try:
             _init_existing_kodi_playlist(playqueue, pos)
@@ -199,8 +199,7 @@ def _playback_init(plex_id, plex_type, playqueue, pos):
         return
     # "Usual" case - consider trailers and parts and build both Kodi and Plex
     # playqueues
-    # Pass dummy PKC video with 0 length so Kodi immediately stops playback
+    # Release default.py
-    # and we can build our own playqueue.
     _ensure_resolve()
     api = API(xml[0])
     trailers = False
@@ -270,9 +269,14 @@ def _ensure_resolve(abort=False):
     if RESOLVE:
         # Releases the other Python thread without a ListItem
         transfer.send(True)
-        # Shows PKC error message
+        # Wait for default.py to have completed xbmcplugin.setResolvedUrl()
-        # transfer.send(None)
+        transfer.wait_for_transfer(source='default')
     if abort:
+        utils.dialog('notification',
+                     heading='{plex}',
+                     message=utils.lang(30128),
+                     icon='{error}',
+                     time=3000)
         # Reset some playback variables
         app.PLAYSTATE.context_menu_play = False
         app.PLAYSTATE.force_transcode = False
@@ -403,8 +407,7 @@ def _conclude_playback(playqueue, pos):
         playurl = item.file
     if not playurl:
         LOG.info('Did not get a playurl, aborting playback silently')
-        app.PLAYSTATE.resume_playback = False
+        _ensure_resolve(abort=True)
-        transfer.send(True)
         return
     listitem.setPath(utils.try_encode(playurl))
     if item.playmethod == 'DirectStream':

resources/lib/playback_starter.py

@@ -29,6 +29,8 @@ class PlaybackTask(backgroundthread.Task):
             # E.g. other add-ons scanning for Extras folder
             LOG.debug('Detected 3rd party add-on call - ignoring')
             transfer.send(True)
+            # Wait for default.py to have completed xbmcplugin.setResolvedUrl()
+            transfer.wait_for_transfer(source='default')
             return
         params = dict(utils.parse_qsl(params))
         mode = params.get('mode')

resources/lib/transfer.py

@@ -14,7 +14,8 @@ import xbmcgui
 LOG = getLogger('PLEX.transfer')
 MONITOR = xbmc.Monitor()
 WINDOW = xbmcgui.Window(10000)
-WINDOW_RESULT = 'plexkodiconnect.result'.encode('utf-8')
+WINDOW_UPSTREAM = 'plexkodiconnect.result.upstream'.encode('utf-8')
+WINDOW_DOWNSTREAM = 'plexkodiconnect.result.downstream'.encode('utf-8')
 WINDOW_COMMAND = 'plexkodiconnect.command'.encode('utf-8')
 
 
@@ -90,7 +91,7 @@ def de_serialize(answ):
         raise NotImplementedError('Not implemented: %s' % answ)
 
 
-def send(pkc_listitem):
+def send(pkc_listitem, target='default'):
     """
     Pickles the obj to the window variable. Use to transfer Python
     objects between different PKC python instances (e.g. if default.py is
@@ -98,18 +99,27 @@ def send(pkc_listitem):
 
     obj can be pretty much any Python object. However, classes and
     functions won't work. See the Pickle documentation
+
+    Set target='default' if you send data TO another Python default.py
+    instance, 'main' if your default.py needs to send to the main thread
     """
+    window = WINDOW_DOWNSTREAM if target == 'default' else WINDOW_UPSTREAM
     LOG.debug('Sending: %s', pkc_listitem)
-    kodi_window(WINDOW_RESULT,
+    kodi_window(window,
                 value=json.dumps(serialize(pkc_listitem)))
 
 
-def wait_for_transfer():
+def wait_for_transfer(source='main'):
+    """
+    Set source='default' if you wait for data FROM another Python default.py
+    instance, 'main' if your default.py needs to wait for the main thread
+    """
+    window = WINDOW_DOWNSTREAM if source == 'main' else WINDOW_UPSTREAM
     result = ''
     while not result:
-        result = kodi_window(WINDOW_RESULT)
+        result = kodi_window(window)
         if result:
-            kodi_window(WINDOW_RESULT, clear=True)
+            kodi_window(window, clear=True)
             LOG.debug('Received')
             result = json.loads(result)
             return de_serialize(result)