[pulseaudio-discuss] [PATCH 08/15] sink, source: Call set_mute() from mute_changed()

[Tanu Kaskinen]

This refactoring reduces duplication, as mute_changed() used to do the
same things as set_mute(). Other benefits are improved logging
(set_mute() logs the mute change, mute_changed() used to not do that)
and the soft mute state is kept up to date, because set_mute() sends
the SET_MUTE message to the IO thread.

The set_mute_in_progress flag is an extra precaution for preventing
recursion in case a sink/source implementation's set_mute() callback
causes mute_changed() to be called. Currently there are no such
implementations, but I think that would be a valid thing to do, so
some day there might be such implementation.
---
 src/pulsecore/sink.c   | 19 ++++++++++++-------
 src/pulsecore/sink.h   |  2 ++
 src/pulsecore/source.c | 19 ++++++++++++-------
 src/pulsecore/source.h |  2 ++
 4 files changed, 28 insertions(+), 14 deletions(-)

diff --git a/src/pulsecore/sink.c b/src/pulsecore/sink.c
index 18b163d..5de1d5f 100644
--- a/src/pulsecore/sink.c
+++ b/src/pulsecore/sink.c
@@ -2207,8 +2207,11 @@ void pa_sink_set_mute(pa_sink *s, bool mute, bool save) {
     s->muted = mute;
     s->save_muted = save;
 
-    if (!(s->flags & PA_SINK_DEFERRED_VOLUME) && s->set_mute)
+    if (!(s->flags & PA_SINK_DEFERRED_VOLUME) && s->set_mute) {
+        s->set_mute_in_progress = true;
         s->set_mute(s);
+        s->set_mute_in_progress = false;
+    }
 
     if (!PA_SINK_IS_LINKED(s->state))
         return;
@@ -2252,15 +2255,17 @@ void pa_sink_mute_changed(pa_sink *s, bool new_muted) {
     pa_assert_ctl_context();
     pa_assert(PA_SINK_IS_LINKED(s->state));
 
-    /* The sink implementor may call this if the volume changed to make sure everyone is notified */
-
-    if (s->muted == new_muted)
+    if (s->set_mute_in_progress)
         return;
 
-    s->muted = new_muted;
-    s->save_muted = true;
+    /* pa_sink_set_mute() does this same check, so this may appear redundant,
+     * but we must have this here also, because the save parameter of
+     * pa_sink_set_mute() would otherwise have unintended side effects (saving
+     * the mute state when it shouldn't be saved). */
+    if (new_muted == s->muted)
+        return;
 
-    pa_subscription_post(s->core, PA_SUBSCRIPTION_EVENT_SINK|PA_SUBSCRIPTION_EVENT_CHANGE, s->index);
+    pa_sink_set_mute(s, new_muted, true);
 }
 
 /* Called from main thread */
diff --git a/src/pulsecore/sink.h b/src/pulsecore/sink.h
index 3c796f0..ff97bda 100644
--- a/src/pulsecore/sink.h
+++ b/src/pulsecore/sink.h
@@ -118,6 +118,8 @@ struct pa_sink {
 
     unsigned priority;
 
+    bool set_mute_in_progress;
+
     /* Called when the main loop requests a state change. Called from
      * main loop context. If returns -1 the state change will be
      * inhibited */
diff --git a/src/pulsecore/source.c b/src/pulsecore/source.c
index 4faaf23..13df33a 100644
--- a/src/pulsecore/source.c
+++ b/src/pulsecore/source.c
@@ -1800,8 +1800,11 @@ void pa_source_set_mute(pa_source *s, bool mute, bool save) {
     s->muted = mute;
     s->save_muted = save;
 
-    if (!(s->flags & PA_SOURCE_DEFERRED_VOLUME) && s->set_mute)
+    if (!(s->flags & PA_SOURCE_DEFERRED_VOLUME) && s->set_mute) {
+        s->set_mute_in_progress = true;
         s->set_mute(s);
+        s->set_mute_in_progress = false;
+    }
 
     if (!PA_SOURCE_IS_LINKED(s->state))
         return;
@@ -1845,15 +1848,17 @@ void pa_source_mute_changed(pa_source *s, bool new_muted) {
     pa_assert_ctl_context();
     pa_assert(PA_SOURCE_IS_LINKED(s->state));
 
-    /* The source implementor may call this if the mute state changed to make sure everyone is notified */
-
-    if (s->muted == new_muted)
+    if (s->set_mute_in_progress)
         return;
 
-    s->muted = new_muted;
-    s->save_muted = true;
+    /* pa_source_set_mute() does this same check, so this may appear redundant,
+     * but we must have this here also, because the save parameter of
+     * pa_source_set_mute() would otherwise have unintended side effects
+     * (saving the mute state when it shouldn't be saved). */
+    if (new_muted == s->muted)
+        return;
 
-    pa_subscription_post(s->core, PA_SUBSCRIPTION_EVENT_SOURCE|PA_SUBSCRIPTION_EVENT_CHANGE, s->index);
+    pa_source_set_mute(s, new_muted, true);
 }
 
 /* Called from main thread */
diff --git a/src/pulsecore/source.h b/src/pulsecore/source.h
index 6318595..ca2ed59 100644
--- a/src/pulsecore/source.h
+++ b/src/pulsecore/source.h
@@ -118,6 +118,8 @@ struct pa_source {
 
     unsigned priority;
 
+    bool set_mute_in_progress;
+
     /* Called when the main loop requests a state change. Called from
      * main loop context. If returns -1 the state change will be
      * inhibited */
-- 
1.8.3.1