embedded snapshot: use condition variable

[vlc] / src / control / mediacontrol_audio_video.c

diff --git a/src/control/mediacontrol_audio_video.c b/src/control/mediacontrol_audio_video.c
index cf6f0268c96e3708e587f21aa5c98da3960556aa..17660340fef7b9155324b335b08d4aa45c259314 100644 (file)
--- a/src/control/mediacontrol_audio_video.c
+++ b/src/control/mediacontrol_audio_video.c
@@ -56,7 +56,6 @@ mediacontrol_snapshot( mediacontrol_Instance *self,
                        mediacontrol_Exception *exception )
 {
     (void)a_position;
-    vlc_object_t* p_cache;
     vout_thread_t* p_vout;
     input_thread_t *p_input;
     mediacontrol_RGBPicture *p_pic = NULL;
@@ -67,38 +66,68 @@ mediacontrol_snapshot( mediacontrol_Instance *self,
     libvlc_exception_init( &ex );
     mediacontrol_exception_init( exception );
 
+
+    p_snapshot = malloc( sizeof( snapshot_t ) );
+    if( ! p_snapshot )
+    {
+        RAISE_NULL( mediacontrol_InternalException, "Cannot allocate snapshot" );
+    }
+
     p_input = libvlc_get_input_thread( self->p_media_player, &ex );
     if( ! p_input )
     {
         RAISE_NULL( mediacontrol_InternalException, "No input" );
     }
+
     p_vout = vlc_object_find( p_input, VLC_OBJECT_VOUT, FIND_CHILD );
+    vlc_object_release( p_input );
     if( ! p_vout )
     {
         RAISE_NULL( mediacontrol_InternalException, "No video output" );
     }
-    p_cache = vlc_object_create( p_input, sizeof( vlc_object_t ) );
-    if( p_cache == NULL )
-    {
-        vlc_object_release( p_vout );
-        vlc_object_release( p_input );
-        RAISE_NULL( mediacontrol_InternalException, "Out of memory" );
-    }
-    snprintf( path, 255, "object:%ju", (uintmax_t)(uintptr_t)p_cache );
+
+    /* TODO:
+   vlc_mutex_lock (&lock);
+   mutex_cleanup_push (&lock); // release the mutex in case of cancellation
+
+   while (!foobar)
+       vlc_cond_wait (&wait, &lock);
+
+   --- foobar is now true, do something about it here --
+
+   vlc_cleanup_run (); // release the mutex
+    */
+
+    snprintf( path, 255, "object:%p", p_snapshot );
     var_SetString( p_vout, "snapshot-path", path );
     var_SetString( p_vout, "snapshot-format", "png" );
 
-    vlc_object_lock( p_cache );
+    vlc_mutex_init( &p_snapshot->p_mutex );
+    vlc_cond_init( &p_snapshot->p_condvar );
+
+    vlc_mutex_lock( &p_snapshot->p_mutex );
+    mutex_cleanup_push( &p_snapshot->p_mutex );
+
+    /* Use p_snapshot address as sentinel against spurious vlc_object_wait wakeups.
+
+       If a legitimate wakeup occurs, then p_snapshot->p_data will hold either
+       NULL (in case of error) or a pointer to valid data. */
+    p_snapshot->p_data = ( char* )p_snapshot;
+
     vout_Control( p_vout, VOUT_SNAPSHOT );
-    vlc_object_wait( p_cache );
+    while ( p_snapshot->p_data == ( char* )p_snapshot )
+    {
+        vlc_cond_wait( &p_snapshot->p_condvar, &p_snapshot->p_mutex );
+    }
+    vlc_cleanup_pop();
+
     vlc_object_release( p_vout );
 
-    p_snapshot = ( snapshot_t* ) p_cache->p_private;
-    vlc_object_unlock( p_cache );
-    vlc_object_release( p_cache );
-    vlc_object_release( p_input );
+    vlc_mutex_unlock( &p_snapshot->p_mutex );
+    vlc_cond_destroy( &p_snapshot->p_condvar );
+    vlc_mutex_destroy( &p_snapshot->p_mutex );
 
-    if( p_snapshot )
+    if( p_snapshot->p_data )
     {
         /* Note: p_snapshot->p_data is directly used, not copied. Thus
            do not free it here. */
@@ -123,7 +152,7 @@ mediacontrol_snapshot( mediacontrol_Instance *self,
 
 static
 int mediacontrol_showtext( vout_thread_t *p_vout, int i_channel,
-                           char *psz_string, text_style_t *p_style,
+                           const char *psz_string, text_style_t *p_style,
                            int i_flags, int i_hmargin, int i_vmargin,
                            mtime_t i_start, mtime_t i_stop )
 {
@@ -142,13 +171,17 @@ mediacontrol_display_text( mediacontrol_Instance *self,
                            mediacontrol_Exception *exception )
 {
     vout_thread_t *p_vout = NULL;
-    char* psz_message;
     input_thread_t *p_input;
     libvlc_exception_t ex;
 
     libvlc_exception_init( &ex );
     mediacontrol_exception_init( exception );
 
+    if( !message )
+    {
+        RAISE_VOID( mediacontrol_InternalException, "Empty text" );
+    }
+
     p_input = libvlc_get_input_thread( self->p_media_player, &ex );
     if( ! p_input )
     {
@@ -160,12 +193,6 @@ mediacontrol_display_text( mediacontrol_Instance *self,
         RAISE_VOID( mediacontrol_InternalException, "No video output" );
     }
 
-    psz_message = strdup( message );
-    if( !psz_message )
-    {
-        RAISE_VOID( mediacontrol_InternalException, "no more memory" );
-    }
-
     if( begin->origin == mediacontrol_RelativePosition &&
         begin->value == 0 &&
         end->origin == mediacontrol_RelativePosition )
@@ -179,7 +206,7 @@ mediacontrol_display_text( mediacontrol_Instance *self,
                                                               mediacontrol_MediaTime,
                                                               end->value );
 
-        mediacontrol_showtext( p_vout, DEFAULT_CHAN, psz_message, NULL,
+        mediacontrol_showtext( p_vout, DEFAULT_CHAN, message, NULL,
                                OSD_ALIGN_BOTTOM | OSD_ALIGN_LEFT, 0, 0,
                                i_now, i_now + i_duration );
     }
@@ -199,7 +226,7 @@ mediacontrol_display_text( mediacontrol_Instance *self,
                                           ( mediacontrol_Position * ) end );
         i_fin += i_now;
 
-        vout_ShowTextAbsolute( p_vout, DEFAULT_CHAN, psz_message, NULL,
+        vout_ShowTextAbsolute( p_vout, DEFAULT_CHAN, message, NULL,
                                OSD_ALIGN_BOTTOM | OSD_ALIGN_LEFT, 0, 0,
                                i_debut, i_fin );
     }