Changeset a901e3b6074c1894f8e27039b5ad414df63bde75

Timestamp:

08/07/07 17:22:53 (1 year ago)

Author:

Pierre d'Herbemont <pdherbemont@videolan.org>

git-committer:

Pierre d'Herbemont <pdherbemont@videolan.org> 1183908173 +0000

git-parent:

[2f6a9d1a2bad2eee1b8ea6330af1b7dc487008da]

git-author:

Pierre d'Herbemont <pdherbemont@videolan.org> 1183908173 +0000

Message:

Libvlc: Make medi_instance thread safe and implement the basics for refcounting.

Files:

• src/control/libvlc_internal.h (modified) (1 diff)
• src/control/media_instance.c (modified) (16 diffs)

src/control/libvlc_internal.h

@@ -87 +87 @@
-struct libvlc_media_instance_t
-{
+    int                i_refcount;
+    vlc_mutex_t        object_lock;
-    int i_input_id;  /* Input object id. We don't use a pointer to
-                        avoid any crash */

src/control/media_instance.c

@@ -30 +30 @@
-/*
- * Release the associated input thread
+ *
+ * Object lock is NOT held.
- */
-static void release_input_thread( libvlc_media_instance_t *p_mi ) 
@@ -37 +39 @@
-    libvlc_exception_t p_e;
-
-    /* XXX: locking */
-    libvlc_exception_init( &p_e );
-
@@ -63 +64 @@
- * Retrieve the input thread. Be sure to release the object
- * once you are done with it. (libvlc Internal)
+ *
+ * Object lock is held.
- */
-input_thread_t *libvlc_get_input_thread( libvlc_media_instance_t *p_mi,
@@ -69 +72 @@
-    input_thread_t *p_input_thread;
-
+    vlc_mutex_lock( &p_mi->object_lock );
+
-    if( !p_mi || p_mi->i_input_id == -1 )
+    {
+        vlc_mutex_unlock( &p_mi->object_lock );
-        RAISENULL( "Input is NULL" );
+    }
-
-    p_input_thread = (input_thread_t*)vlc_object_get(
@@ -76 +84 @@
-                                             p_mi->i_input_id );
-    if( !p_input_thread )
+    {
+        vlc_mutex_unlock( &p_mi->object_lock );
-        RAISENULL( "Input does not exist" );
-
+
+
+
-    return p_input_thread;
-}
@@ -101 +113 @@
-    p_mi->p_libvlc_instance = p_libvlc_instance;
-    p_mi->i_input_id = -1;
+    /* refcount strategy:
+     * - All items created by _new start with a refcount set to 1
+     * - Accessor _release decrease the refcount by 1, if after that
+     *   operation the refcount is 0, the object is destroyed.
+     * - Accessor _retain increase the refcount by 1 (XXX: to implement) */
+    p_mi->i_refcount = 1;
+    /* object_lock strategy:
+     * - No lock held in constructor
+     * - Lock when accessing all variable this lock is held
+     * - Lock when attempting to destroy the object the lock is also held */
+    vlc_mutex_init( p_mi->p_libvlc_instance->p_libvlc_int,
+                    &p_mi->object_lock );
-
-    return p_mi;
@@ -125 +149 @@
-    p_mi->p_libvlc_instance = p_mi->p_md->p_libvlc_instance;
-    p_mi->i_input_id = -1;
+    /* same strategy as before */
+    p_mi->i_refcount = 1;
+    /* same strategy as before */
+    vlc_mutex_init( p_mi->p_libvlc_instance->p_libvlc_int,
+                    &p_mi->object_lock );
-
-    return p_mi;
@@ -167 +196 @@
-/**************************************************************************
- * Destroy a Media Instance object (libvlc internal)
+ *
+ * Warning: No lock held here, but hey, this is internal.
- **************************************************************************/
-void libvlc_media_instance_destroy( libvlc_media_instance_t *p_mi )
@@ -173 +204 @@
-    libvlc_exception_t p_e;
-
-    /* XXX: locking */
-    libvlc_exception_init( &p_e );
-
@@ -196 +226 @@
-void libvlc_media_instance_release( libvlc_media_instance_t *p_mi )
-{
-    /* XXX: locking */
-
-    if( !p_mi )
-        return;
-
+    vlc_mutex_lock( &p_mi->object_lock );
+    
+    p_mi->i_refcount--;
+    if( p_mi->i_refcount > 0 )
+    {
+        vlc_mutex_unlock( &p_mi->object_lock );
+        return;
+    }
+
-    release_input_thread( p_mi );
-
-    libvlc_media_descriptor_destroy( p_mi->p_md );
-
+    vlc_mutex_unlock( &p_mi->object_lock );
-    free( p_mi );
-}
@@ -218 +256 @@
-    (void)p_e;
-
-    /* XXX : lock */
-
-    if( !p_mi )
-        return;
-
+    vlc_mutex_lock( &p_mi->object_lock );
+    
-    release_input_thread( p_mi );
-
@@ -230 +268 @@
-    {
-        p_mi->p_md = NULL;
+        vlc_mutex_unlock( &p_mi->object_lock );
-        return; /* It is ok to pass a NULL md */
-    }
@@ -239 +278 @@
-    p_mi->p_libvlc_instance = p_md->p_libvlc_instance;
-
+    vlc_mutex_unlock( &p_mi->object_lock );
-}
-
@@ -265 +305 @@
-    input_thread_t * p_input_thread;
-
-
-
+
+
+
+
+
-        vlc_value_t val;
-        val.i_int = PLAYING_S;
-
-        /* A thread alread exists, send it a play message */
-        p_input_thread = libvlc_get_input_thread( p_mi, p_e );
-
-        if( !p_input_thread )
-            return;
-
-        input_Control( p_input_thread, INPUT_CONTROL_SET_STATE, PLAYING_S );
-        vlc_object_release( p_input_thread );
@@ -281 +318 @@
-    }
-
+    vlc_mutex_lock( &p_mi->object_lock );
+    
-    if( !p_mi->p_md )
-    {
-        libvlc_exception_raise( p_e, "no associated media descriptor" );
+        vlc_mutex_unlock( &p_mi->object_lock );
-        return;
-    }
@@ -293 +333 @@
-    /* will be released in media_instance_release() */
-    vlc_object_yield( p_input_thread );
+
+    vlc_mutex_unlock( &p_mi->object_lock );
-}
-