audioscrobbler: do not mix vlc_object and vlc_thread APIs...

Also do not needlessly lock after unregistering the callbacks. We have
to assume that when var_DelCallback returns, any pending callback
invocation has be completed. Otherwise, we would any crash when Close()
releases the mutex, destroys it, and the callback then tries to acquire
the mutex.

modules/misc/audioscrobbler.c

@@ -75,6 +75,7 @@ struct intf_sys_t
     int                     i_songs;            /**< number of songs        */
 
     vlc_mutex_t             lock;               /**< p_sys mutex            */
+    vlc_cond_t              wait;               /**< song to submit event   */
 
     /* data about audioscrobbler session */
     mtime_t                 next_exchange;      /**< when can we send data  */
@@ -181,6 +182,7 @@ static int Open( vlc_object_t *p_this )
     p_intf->p_sys = p_sys;
 
     vlc_mutex_init( &p_sys->lock );
+    vlc_cond_init( p_intf, &p_sys->wait );
 
     p_playlist = pl_Yield( p_intf );
     PL_LOCK;
@@ -226,8 +228,6 @@ static void Close( vlc_object_t *p_this )
     }
 
     p_intf->b_dead = true;
-    /* we lock the mutex in case p_sys is being accessed from a callback */
-    vlc_mutex_lock ( &p_sys->lock );
     int i;
     for( i = 0; i < p_sys->i_songs; i++ )
         DeleteSong( &p_sys->p_queue[i] );
@@ -237,7 +237,7 @@ static void Close( vlc_object_t *p_this )
     free( p_sys->psz_nowp_host );
     free( p_sys->psz_nowp_file );
 #endif
-    vlc_mutex_unlock ( &p_sys->lock );
+    vlc_cond_destroy( &p_sys->wait );
     vlc_mutex_destroy( &p_sys->lock );
     free( p_sys );
 }
@@ -264,16 +264,17 @@ static void Run( intf_thread_t *p_intf )
         bool b_wait = false;
 
         vlc_restorecancel( canc );
-        vlc_object_lock( p_intf );
-        vlc_cleanup_push( __vlc_object_unlock, p_intf );
+        vlc_mutex_lock( &p_sys->lock );
+        mutex_cleanup_push( &p_sys->lock );
 
         if( mdate() < p_sys->next_exchange )
             /* wait until we can resubmit, i.e.  */
-            b_wait = vlc_object_timedwait( p_intf, p_sys->next_exchange ) == 0;
+            b_wait = vlc_cond_timedwait( &p_sys->wait, &p_sys->lock,
+                                          p_sys->next_exchange ) == 0;
         else
             /* wait for data to submit */
             /* we are signaled each time there is a song to submit */
-            vlc_object_wait( p_intf );
+            vlc_cond_wait( &p_sys->wait, &p_sys->lock );
         vlc_cleanup_run();
         canc = vlc_savecancel();
 
@@ -629,7 +630,7 @@ static void AddToQueue ( intf_thread_t *p_this )
     p_sys->i_songs++;
 
     /* signal the main loop we have something to submit */
-    vlc_object_signal( VLC_OBJECT( p_this ) );
+    vlc_cond_signal( &p_sys->wait );
 
 end:
     DeleteSong( &p_sys->p_current_song );