sink, source: Assign to reference_volume from only one place

Forcing all reference volume changes to go through
set_reference_volume_direct() makes it easier to check where the
reference volume is changed, and it also allows us to have only one
place where notifications for changed reference volume are sent.

src/pulsecore/sink-input.c

@@ -1632,6 +1632,7 @@ int pa_sink_input_start_move(pa_sink_input *i) {
  * their volume - this function does all that by using recursion. */
 static void update_volume_due_to_moving(pa_sink_input *i, pa_sink *dest) {
     pa_cvolume old_volume;
+    pa_cvolume new_volume;
 
     pa_assert(i);
     pa_assert(dest);
@@ -1703,25 +1704,21 @@ static void update_volume_due_to_moving(pa_sink_input *i, pa_sink *dest) {
          *         (sinks that use volume sharing should always have
          *          soft_volume of 0 dB) */
 
-        old_volume = i->origin_sink->reference_volume;
-
-        i->origin_sink->reference_volume = root_sink->reference_volume;
-        pa_cvolume_remap(&i->origin_sink->reference_volume, &root_sink->channel_map, &i->origin_sink->channel_map);
+        new_volume = root_sink->reference_volume;
+        pa_cvolume_remap(&new_volume, &root_sink->channel_map, &i->origin_sink->channel_map);
+        pa_sink_set_reference_volume_direct(i->origin_sink, &new_volume);
 
         i->origin_sink->real_volume = root_sink->real_volume;
         pa_cvolume_remap(&i->origin_sink->real_volume, &root_sink->channel_map, &i->origin_sink->channel_map);
 
         pa_assert(pa_cvolume_is_norm(&i->origin_sink->soft_volume));
 
-        /* Notify others about the changed sink volume. If you wonder whether
-         * i->origin_sink->set_volume() should be called somewhere, that's not
-         * the case, because sinks that use volume sharing shouldn't have any
-         * internal volume that set_volume() would update. If you wonder
-         * whether the thread_info variables should be synced, yes, they
-         * should, and it's done by the PA_SINK_MESSAGE_FINISH_MOVE message
-         * handler. */
-        if (!pa_cvolume_equal(&i->origin_sink->reference_volume, &old_volume))
-            pa_subscription_post(i->core, PA_SUBSCRIPTION_EVENT_SINK|PA_SUBSCRIPTION_EVENT_CHANGE, i->origin_sink->index);
+        /* If you wonder whether i->origin_sink->set_volume() should be called
+         * somewhere, that's not the case, because sinks that use volume
+         * sharing shouldn't have any internal volume that set_volume() would
+         * update. If you wonder whether the thread_info variables should be
+         * synced, yes, they should, and it's done by the
+         * PA_SINK_MESSAGE_FINISH_MOVE message handler. */
 
         /* Recursively update origin sink inputs. */
         PA_IDXSET_FOREACH(origin_sink_input, i->origin_sink->inputs, idx)

src/pulsecore/sink.c

@@ -1954,13 +1954,11 @@ static bool update_reference_volume(pa_sink *s, const pa_cvolume *v, const pa_ch
     pa_cvolume_remap(&volume, channel_map, &s->channel_map);
 
     reference_volume_changed = !pa_cvolume_equal(&volume, &s->reference_volume);
-    s->reference_volume = volume;
+    pa_sink_set_reference_volume_direct(s, &volume);
 
     s->save_volume = (!reference_volume_changed && s->save_volume) || save;
 
-    if (reference_volume_changed)
-        pa_subscription_post(s->core, PA_SUBSCRIPTION_EVENT_SINK|PA_SUBSCRIPTION_EVENT_CHANGE, s->index);
-    else if (!(s->flags & PA_SINK_SHARE_VOLUME_WITH_MASTER))
+    if (!reference_volume_changed && !(s->flags & PA_SINK_SHARE_VOLUME_WITH_MASTER))
         /* If the root sink's volume doesn't change, then there can't be any
          * changes in the other sinks in the sink tree either.
          *
@@ -3798,3 +3796,27 @@ done:
 
     return out_formats;
 }
+
+/* Called from the main thread. */
+void pa_sink_set_reference_volume_direct(pa_sink *s, const pa_cvolume *volume) {
+    pa_cvolume old_volume;
+    char old_volume_str[PA_CVOLUME_SNPRINT_VERBOSE_MAX];
+    char new_volume_str[PA_CVOLUME_SNPRINT_VERBOSE_MAX];
+
+    pa_assert(s);
+    pa_assert(volume);
+
+    old_volume = s->reference_volume;
+
+    if (pa_cvolume_equal(volume, &old_volume))
+        return;
+
+    s->reference_volume = *volume;
+    pa_log_debug("The reference volume of sink %s changed from %s to %s.", s->name,
+                 pa_cvolume_snprint_verbose(old_volume_str, sizeof(old_volume_str), &old_volume, &s->channel_map,
+                                            s->flags & PA_SINK_DECIBEL_VOLUME),
+                 pa_cvolume_snprint_verbose(new_volume_str, sizeof(new_volume_str), volume, &s->channel_map,
+                                            s->flags & PA_SINK_DECIBEL_VOLUME));
+
+    pa_subscription_post(s->core, PA_SUBSCRIPTION_EVENT_SINK|PA_SUBSCRIPTION_EVENT_CHANGE, s->index);
+}

src/pulsecore/sink.h

@@ -503,6 +503,13 @@ void pa_sink_invalidate_requested_latency(pa_sink *s, bool dynamic);
 
 pa_usec_t pa_sink_get_latency_within_thread(pa_sink *s);
 
+/* Called from the main thread, from sink-input.c only. The normal way to set
+ * the sink reference volume is to call pa_sink_set_volume(), but the flat
+ * volume logic in sink-input.c needs also a function that doesn't do all the
+ * extra stuff that pa_sink_set_volume() does. This function simply sets
+ * s->reference_volume and fires change notifications. */
+void pa_sink_set_reference_volume_direct(pa_sink *s, const pa_cvolume *volume);
+
 /* Verify that we called in IO context (aka 'thread context), or that
  * the sink is not yet set up, i.e. the thread not set up yet. See
  * pa_assert_io_context() in thread-mq.h for more information. */

src/pulsecore/source-output.c

@@ -1263,6 +1263,7 @@ int pa_source_output_start_move(pa_source_output *o) {
  * their volume - this function does all that by using recursion. */
 static void update_volume_due_to_moving(pa_source_output *o, pa_source *dest) {
     pa_cvolume old_volume;
+    pa_cvolume new_volume;
 
     pa_assert(o);
     pa_assert(dest);
@@ -1336,25 +1337,21 @@ static void update_volume_due_to_moving(pa_source_output *o, pa_source *dest) {
          *         (sources that use volume sharing should always have
          *          soft_volume of 0 dB) */
 
-        old_volume = o->destination_source->reference_volume;
-
-        o->destination_source->reference_volume = root_source->reference_volume;
-        pa_cvolume_remap(&o->destination_source->reference_volume, &root_source->channel_map, &o->destination_source->channel_map);
+        new_volume = root_source->reference_volume;
+        pa_cvolume_remap(&new_volume, &root_source->channel_map, &o->destination_source->channel_map);
+        pa_source_set_reference_volume_direct(o->destination_source, &new_volume);
 
         o->destination_source->real_volume = root_source->real_volume;
         pa_cvolume_remap(&o->destination_source->real_volume, &root_source->channel_map, &o->destination_source->channel_map);
 
         pa_assert(pa_cvolume_is_norm(&o->destination_source->soft_volume));
 
-        /* Notify others about the changed source volume. If you wonder whether
-         * o->destination_source->set_volume() should be called somewhere, that's not
-         * the case, because sources that use volume sharing shouldn't have any
-         * internal volume that set_volume() would update. If you wonder
-         * whether the thread_info variables should be synced, yes, they
-         * should, and it's done by the PA_SOURCE_MESSAGE_FINISH_MOVE message
-         * handler. */
-        if (!pa_cvolume_equal(&o->destination_source->reference_volume, &old_volume))
-            pa_subscription_post(o->core, PA_SUBSCRIPTION_EVENT_SOURCE|PA_SUBSCRIPTION_EVENT_CHANGE, o->destination_source->index);
+        /* If you wonder whether o->destination_source->set_volume() should be
+         * called somewhere, that's not the case, because sources that use
+         * volume sharing shouldn't have any internal volume that set_volume()
+         * would update. If you wonder whether the thread_info variables should
+         * be synced, yes, they should, and it's done by the
+         * PA_SOURCE_MESSAGE_FINISH_MOVE message handler. */
 
         /* Recursively update origin source outputs. */
         PA_IDXSET_FOREACH(destination_source_output, o->destination_source->outputs, idx)

src/pulsecore/source.c

@@ -1548,13 +1548,11 @@ static bool update_reference_volume(pa_source *s, const pa_cvolume *v, const pa_
     pa_cvolume_remap(&volume, channel_map, &s->channel_map);
 
     reference_volume_changed = !pa_cvolume_equal(&volume, &s->reference_volume);
-    s->reference_volume = volume;
+    pa_source_set_reference_volume_direct(s, &volume);
 
     s->save_volume = (!reference_volume_changed && s->save_volume) || save;
 
-    if (reference_volume_changed)
-        pa_subscription_post(s->core, PA_SUBSCRIPTION_EVENT_SOURCE|PA_SUBSCRIPTION_EVENT_CHANGE, s->index);
-    else if (!(s->flags & PA_SOURCE_SHARE_VOLUME_WITH_MASTER))
+    if (!reference_volume_changed && !(s->flags & PA_SOURCE_SHARE_VOLUME_WITH_MASTER))
         /* If the root source's volume doesn't change, then there can't be any
          * changes in the other source in the source tree either.
          *
@@ -2868,3 +2866,27 @@ done:
 
     return out_formats;
 }
+
+/* Called from the main thread. */
+void pa_source_set_reference_volume_direct(pa_source *s, const pa_cvolume *volume) {
+    pa_cvolume old_volume;
+    char old_volume_str[PA_CVOLUME_SNPRINT_VERBOSE_MAX];
+    char new_volume_str[PA_CVOLUME_SNPRINT_VERBOSE_MAX];
+
+    pa_assert(s);
+    pa_assert(volume);
+
+    old_volume = s->reference_volume;
+
+    if (pa_cvolume_equal(volume, &old_volume))
+        return;
+
+    s->reference_volume = *volume;
+    pa_log_debug("The reference volume of source %s changed from %s to %s.", s->name,
+                 pa_cvolume_snprint_verbose(old_volume_str, sizeof(old_volume_str), &old_volume, &s->channel_map,
+                                            s->flags & PA_SOURCE_DECIBEL_VOLUME),
+                 pa_cvolume_snprint_verbose(new_volume_str, sizeof(new_volume_str), volume, &s->channel_map,
+                                            s->flags & PA_SOURCE_DECIBEL_VOLUME));
+
+    pa_subscription_post(s->core, PA_SUBSCRIPTION_EVENT_SOURCE|PA_SUBSCRIPTION_EVENT_CHANGE, s->index);
+}

src/pulsecore/source.h

@@ -426,6 +426,13 @@ bool pa_source_volume_change_apply(pa_source *s, pa_usec_t *usec_to_next);
 void pa_source_invalidate_requested_latency(pa_source *s, bool dynamic);
 pa_usec_t pa_source_get_latency_within_thread(pa_source *s);
 
+/* Called from the main thread, from source-output.c only. The normal way to
+ * set the source reference volume is to call pa_source_set_volume(), but the
+ * flat volume logic in source-output.c needs also a function that doesn't do
+ * all the extra stuff that pa_source_set_volume() does. This function simply
+ * sets s->reference_volume and fires change notifications. */
+void pa_source_set_reference_volume_direct(pa_source *s, const pa_cvolume *volume);
+
 #define pa_source_assert_io_context(s) \
     pa_assert(pa_thread_mq_get() || !PA_SOURCE_IS_LINKED((s)->state))