output/Internal: move the Mutex to struct AudioOutputControl

struct AudioOutput should not know or care about multi-threading.

src/output/Control.cxx

@@ -41,8 +41,7 @@ struct notify audio_output_client_notify;
 AudioOutputControl::AudioOutputControl(AudioOutput *_output,
 				       AudioOutputClient &_client)
 	:output(_output), client(_client),
-	 thread(BIND_THIS_METHOD(Task)),
+	 thread(BIND_THIS_METHOD(Task))
-	 mutex(output->mutex)
 {
 }
 

src/output/Control.hxx

@@ -23,6 +23,7 @@
 #include "Source.hxx"
 #include "AudioFormat.hxx"
 #include "thread/Thread.hxx"
+#include "thread/Mutex.hxx"
 #include "thread/Cond.hxx"
 #include "system/PeriodClock.hxx"
 #include "Compiler.h"
@@ -203,7 +204,10 @@ class AudioOutputControl {
 	bool skip_delay;
 
 public:
-	Mutex &mutex;
+	/**
+	 * This mutex protects #open, #fail_timer, #pipe.
+	 */
+	mutable Mutex mutex;
 
 	AudioOutputControl(AudioOutput *_output, AudioOutputClient &_client);
 

src/output/Internal.hxx

@@ -22,7 +22,6 @@
 
 #include "AudioFormat.hxx"
 #include "filter/Observer.hxx"
-#include "thread/Mutex.hxx"
 
 class PreparedFilter;
 class MusicPipe;
@@ -106,11 +105,6 @@ struct AudioOutput {
 	 */
 	FilterObserver convert_filter;
 
-	/**
-	 * This mutex protects #open, #fail_timer, #pipe.
-	 */
-	mutable Mutex mutex;
-
 	/**
 	 * Throws #std::runtime_error on error.
 	 */

src/output/Thread.cxx

@@ -480,7 +480,7 @@ AudioOutputControl::Task()
 
 		if (command == Command::NONE) {
 			woken_for_play = false;
-			cond.wait(output->mutex);
+			cond.wait(mutex);
 		}
 	}
 }

src/output/plugins/AlsaOutputPlugin.cxx

@@ -26,6 +26,7 @@
 #include "mixer/MixerList.hxx"
 #include "pcm/PcmExport.hxx"
 #include "system/ByteOrder.hxx"
+#include "thread/Mutex.hxx"
 #include "thread/Cond.hxx"
 #include "util/Manual.hxx"
 #include "util/RuntimeError.hxx"

src/output/plugins/sles/SlesOutputPlugin.cxx

@@ -25,6 +25,7 @@
 #include "AndroidSimpleBufferQueue.hxx"
 #include "../../OutputAPI.hxx"
 #include "../../Wrapper.hxx"
+#include "thread/Mutex.hxx"
 #include "thread/Cond.hxx"
 #include "util/Macros.hxx"
 #include "util/Domain.hxx"