media library: remove non-sensical use of spin locks

The code is complete and utter crap either way.

include/vlc_media_library.h

@@ -181,7 +181,6 @@ typedef struct ml_ftree_t      ml_ftree_t;
 
 typedef struct ml_gc_object_t
 {
-    vlc_spinlock_t spin;
     bool           pool;
     uintptr_t      refs;
     void          (*pf_destructor) (struct ml_gc_object_t *);
@@ -514,9 +513,7 @@ static inline void ml_gc_incref( ml_media_t* p_media )
     if( p_gc == NULL )
         return;
 
-    vlc_spin_lock (&p_gc->spin);
     ++p_gc->refs;
-    vlc_spin_unlock (&p_gc->spin);
 }
 
 /**
@@ -532,14 +529,11 @@ static inline void ml_gc_decref( ml_media_t* p_media )
     if( p_gc == NULL )
         return;
 
-    vlc_spin_lock (&p_gc->spin);
     refs = --p_gc->refs;
     pool = p_gc->pool;
-    vlc_spin_unlock (&p_gc->spin);
 
     if( refs == 0 && !pool )
     {
-        vlc_spin_destroy (&p_gc->spin);
         p_gc->pf_destructor (p_gc);
     }
 }

modules/media_library/media_pool.c

@@ -66,7 +66,6 @@ int pool_InsertMedia( media_library_t* p_ml, ml_media_t* p_media, bool locked )
         ml_LockMedia( p_media );
     assert( p_media );
     assert( p_media->i_id > 0 );
-    vlc_spin_lock( &p_media->ml_gc_data.spin );
     if( p_media->ml_gc_data.pool )
     {
         msg_Dbg( p_ml, "Already in pool! %s %d", p_media->psz_uri, p_media->i_id );
@@ -74,7 +73,6 @@ int pool_InsertMedia( media_library_t* p_ml, ml_media_t* p_media, bool locked )
         return VLC_EGENERIC;
     }
     p_media->ml_gc_data.pool = true;
-    vlc_spin_unlock( &p_media->ml_gc_data.spin );
     int i_ret = VLC_SUCCESS;
     vlc_mutex_lock( &p_ml->p_sys->pool_mutex );
     mp_foreachlist( p_ml->p_sys->p_mediapool[ (mediapool_hash(p_media->i_id)) ], p_item )
@@ -128,18 +126,14 @@ void pool_GC( media_library_t* p_ml )
         {
             p_media = p_item->p_media;
             int refs;
-            vlc_spin_lock( &p_media->ml_gc_data.spin );
             refs = p_media->ml_gc_data.refs;
-            vlc_spin_unlock( &p_media->ml_gc_data.spin );
             if( refs == 1 )
             {
                 if( p_prev == NULL )
                     p_ml->p_sys->p_mediapool[i_idx] = p_item->p_next;
                 else
                     p_prev->p_next = p_item->p_next;
-                vlc_spin_lock( &p_media->ml_gc_data.spin );
                 p_media->ml_gc_data.pool = false;
-                vlc_spin_unlock( &p_media->ml_gc_data.spin );
                 ml_gc_decref( p_item->p_media );//This should destroy the object
                 free( p_item );
             }

src/misc/media_library.c

@@ -57,10 +57,6 @@ static void *ml_gc_init (ml_gc_object_t *p_gc, void (*pf_destruct) (ml_gc_object
 
     p_gc->pool = false;
     p_gc->refs = 1;
-    /* Nobody else can possibly lock the spin - it's there as a barrier */
-    vlc_spin_init (&p_gc->spin);
-    vlc_spin_lock (&p_gc->spin);
-    vlc_spin_unlock (&p_gc->spin);
     return p_gc;
 }