Changeset b3c8d478e9091fe55a2513eb8e416162da3bb5e4

Timestamp:

05/07/08 22:13:01 (2 months ago)

Author:

Rémi Denis-Courmont <rem@videolan.org>

git-committer:

Rémi Denis-Courmont <rem@videolan.org> 1210191181 +0300

git-parent:

[5421e9cd54ac4384583f13daf9323304e532c257]

git-author:

Rémi Denis-Courmont <rem@videolan.org> 1210191172 +0300

Message:

Use a per-object spin around the reference count.

So we don't contend for the global structure lock all the time.

Files:

• src/libvlc.h (modified) (1 diff)
• src/misc/objects.c (modified) (18 diffs)

src/libvlc.h

@@ -188 +188 @@
-
-    /* Objects management */
+    vlc_spinlock_t   ref_spin;
-    unsigned         i_refcount;
-    vlc_destructor_t pf_destructor;

src/misc/objects.c

@@ -90 +90 @@
-
-static void vlc_object_destroy( vlc_object_t *p_this );
-static void vlc_object_yield_locked( vlc_object_t *p_this );
-
-/*****************************************************************************
@@ -170 +169 @@
-    }
-
+    vlc_spin_init( &p_priv->ref_spin );
-    p_priv->i_refcount = 1;
-    p_priv->pf_destructor = kVLCDestructor;
@@ -188 +188 @@
-    vlc_mutex_lock( &structure_lock );
-    p_new->i_object_id = p_libvlc_global->i_counter++;
-
-    /* Wooohaa! If *this* fails, we're in serious trouble! Anyway it's
-     * useless to try and recover anything if pp_objects gets smashed. */
@@ -425 +424 @@
-#endif
-
+    vlc_spin_destroy( &p_priv->ref_spin );
-    vlc_mutex_destroy( &p_this->object_lock );
-    vlc_cond_destroy( &p_this->object_wait );
@@ -714 +714 @@
-                if( pp_objects[i_middle+1]->i_object_id == i_id )
-                {
-_locked
+
-                    obj = pp_objects[i_middle+1];
-                }
@@ -722 +722 @@
-        else
-        {
-_locked
+
-            vlc_mutex_unlock( &structure_lock );
-            return pp_objects[i_middle];
@@ -750 +750 @@
-    if( !(i_mode & FIND_STRICT) && p_this->i_object_type == i_type )
-    {
-_locked
+
-        vlc_mutex_unlock( &structure_lock );
-        return p_this;
@@ -798 +798 @@
-    vlc_mutex_lock( &structure_lock );
-
-    /* Avoid obvious freed object uses */
-    assert( vlc_internals( p_this )->i_refcount > 0 );
-
-    /* If have the requested name ourselves, don't look further */
-    if( !(i_mode & FIND_STRICT)
@@ -806 +803 @@
-        && !strcmp( p_this->psz_object_name, psz_name ) )
-    {
-_locked
+
-        vlc_mutex_unlock( &structure_lock );
-        return p_this;
@@ -842 +839 @@
-
-/**
-
-
-
-
-
-
-
-
-
+
+
+
+
+
+
+
-    /* Avoid obvious freed object uses */
-
-
+
-    /* Increment the counter */
-
-
-
-
-
-
-
-
-
-
-
+
+
+
-
-/*****************************************************************************
@@ -873 +859 @@
-void __vlc_object_release( vlc_object_t *p_this )
-{
+    vlc_object_internals_t *internals = vlc_internals( p_this );
-    bool b_should_destroy;
-
+    vlc_spin_lock( &internals->ref_spin );
+    assert( internals->i_refcount > 0 );
+
+    if( internals->i_refcount > 1 )
+    {
+        /* Fast path */
+        /* There are still other references to the object */
+        internals->i_refcount--;
+        vlc_spin_unlock( &internals->ref_spin );
+        return;
+    }
+    vlc_spin_unlock( &internals->ref_spin );
+
+    /* Slow path */
+    /* Remember that we cannot hold the spin while waiting on the mutex */
-    vlc_mutex_lock( &structure_lock );
-
-
-
-
+
+
+
+
+
-
-    if( b_should_destroy )
-    {
-Make sure this object can't be obtained via vlc_find_object now that
-it is freed
+Remove the object from the table so that it cannot be returned from
+vlc_object_find() and friends.
-        libvlc_global_data_t *p_libvlc_global = vlc_global();
-        int i_index;
-
-        /* Wooohaa! If *this* fails, we're in serious trouble! Anyway it's
-         * useless to try and recover anything if pp_objects gets smashed. */
-        i_index = FindIndex( p_this, p_libvlc_global->pp_objects,
-                             p_libvlc_global->i_objects );
@@ -914 +915 @@
-
-    vlc_mutex_lock( &structure_lock );
-
-    /* Avoid obvious freed object uses */
-    assert( vlc_internals( p_this )->i_refcount > 0 );
-
-    /* Attach the parent to its child */
@@ -1300 +1298 @@
-            if( p_tmp->i_object_type == i_type )
-            {
-_locked
+
-                return p_tmp;
-            }
@@ -1316 +1314 @@
-            if( p_tmp->i_object_type == i_type )
-            {
-_locked
+
-                return p_tmp;
-            }
@@ -1354 +1352 @@
-                && !strcmp( p_tmp->psz_object_name, psz_name ) )
-            {
-_locked
+
-                return p_tmp;
-            }
@@ -1371 +1369 @@
-                && !strcmp( p_tmp->psz_object_name, psz_name ) )
-            {
-_locked
+
-                return p_tmp;
-            }
@@ -1572 +1570 @@
-    }
-
-_locked
+
-
-    p_list->p_values[i_index].p_object = p_object;
@@ -1594 +1592 @@
-    }
-
-_locked
+
-
-    p_list->p_values[p_list->i_count].p_object = p_object;