audio: keep a strong reference on the backend

Since we are going to convert audio_driver-based backends, we need to
properly handle reference counting to allow for a different order of
class finalization (for example, pulse class before base driver class).

Reviewed-by: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

diff --git a/audio/audio_template.h b/audio/audio_template.h
index a1f78d8748b32db2dc618941d63a112790429f90..512abbfe22ff4637fe53788b4c4edf79f5c07ca0 100644 (file)
--- a/audio/audio_template.h
+++ b/audio/audio_template.h
@@ -231,6 +231,7 @@ static void glue (audio_pcm_hw_gc_, TYPE) (HW **hwp)
         glue(hw->pcm_ops->fini_, TYPE) (hw);
         glue(s->nb_hw_voices_, TYPE) += 1;
         glue(audio_pcm_hw_free_resources_ , TYPE) (hw);
+        object_unref(hw->s);
         g_free(hw);
         *hwp = NULL;
     }
@@ -287,7 +288,7 @@ static HW *glue(audio_pcm_hw_add_new_, TYPE)(AudioMixengBackend *s,
      * is guaranteed to be != 0. See the audio_init_nb_voices_* functions.
      */
     hw = g_malloc0(glue(drv->voice_size_, TYPE));
-    hw->s = s;
+    hw->s = AUDIO_MIXENG_BACKEND(object_ref(s));
     hw->pcm_ops = drv->pcm_ops;
 
     QLIST_INIT (&hw->sw_head);
@@ -335,6 +336,7 @@ static HW *glue(audio_pcm_hw_add_new_, TYPE)(AudioMixengBackend *s,
  err1:
     glue (hw->pcm_ops->fini_, TYPE) (hw);
  err0:
+    object_unref(hw->s);
     g_free (hw);
     return NULL;
 }
@@ -441,7 +443,7 @@ static SW *glue(audio_pcm_create_voice_pair_, TYPE)(
     }
 
     sw = g_new0(SW, 1);
-    sw->s = s;
+    sw->s = AUDIO_MIXENG_BACKEND(object_ref(s));
 
     hw = glue(audio_pcm_hw_add_, TYPE)(s, &hw_as);
     if (!hw) {
@@ -461,6 +463,7 @@ err2:
     glue (audio_pcm_hw_del_sw_, TYPE) (sw);
     glue (audio_pcm_hw_gc_, TYPE) (&hw);
 err1:
+    object_unref(sw->s);
     g_free(sw);
     return NULL;
 }
@@ -470,6 +473,8 @@ static void glue (audio_close_, TYPE) (SW *sw)
     glue (audio_pcm_sw_fini_, TYPE) (sw);
     glue (audio_pcm_hw_del_sw_, TYPE) (sw);
     glue (audio_pcm_hw_gc_, TYPE) (&sw->hw);
+
+    object_unref(sw->s);
     g_free (sw);
 }