Avoid race condition in pause, switch to shared_ptr for simpler semantics.

src/common/SoundSDL2.cxx

@@ -100,7 +100,7 @@ void SoundSDL2::setEnabled(bool state)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void SoundSDL2::open(AudioQueue* audioQueue)
+void SoundSDL2::open(shared_ptr<AudioQueue> audioQueue)
 {
   myOSystem.logMessage("SoundSDL2::open started ...", 2);
   mute(true);
@@ -141,10 +141,11 @@ void SoundSDL2::close()
 {
   if(!myIsInitializedFlag) return;
 
+  mute(true);
+
   myAudioQueue = 0;
   myCurrentFragment = 0;
 
-  mute(true);
   myOSystem.logMessage("SoundSDL2::close", 2);
 
 }

src/common/SoundSDL2.hxx

@@ -59,7 +59,7 @@ class SoundSDL2 : public Sound
       Initializes the sound device.  This must be called before any
       calls are made to derived methods.
     */
-    void open(AudioQueue* audioQueue) override;
+    void open(shared_ptr<AudioQueue> audioQueue) override;
 
     /**
       Should be called to close the sound device.  Once called the sound
@@ -117,7 +117,7 @@ class SoundSDL2 : public Sound
     // Audio specification structure
     SDL_AudioSpec myHardwareSpec;
 
-    AudioQueue* myAudioQueue;
+    shared_ptr<AudioQueue> myAudioQueue;
 
     Int16* myCurrentFragment;
     uInt32 myTimeIndex;

src/emucore/Console.cxx

@@ -183,7 +183,7 @@ Console::Console(OSystem& osystem, unique_ptr<Cartridge>& cart,
   }
 
   createAudioQueue();
-  myTIA->setAudioQueue(myAudioQueue.get());
+  myTIA->setAudioQueue(myAudioQueue);
 
   bool joyallow4 = myOSystem.settings().getBool("joyallow4");
   myOSystem.eventHandler().allowAllDirections(joyallow4);
@@ -580,7 +580,7 @@ void Console::initializeAudio()
   // const string& sound = myProperties.get(Cartridge_Sound);
   // myOSystem.sound().setChannels(sound == "STEREO" ? 2 : 1);
 
-  myOSystem.sound().open(myAudioQueue.get());
+  myOSystem.sound().open(myAudioQueue);
 
   // Make sure auto-frame calculation is only enabled when necessary
   myTIA->enableAutoFrame(framerate <= 0);
@@ -754,7 +754,7 @@ void Console::createAudioQueue()
       throw runtime_error("invalid console timing");
   }
 
-  myAudioQueue = make_unique<AudioQueue>(
+  myAudioQueue = make_shared<AudioQueue>(
     fragmentSize,
     AUDIO_QUEUE_CAPACITY_FRAGMENTS,
     myProperties.get(Cartridge_Sound) == "STEREO",

src/emucore/Console.hxx

@@ -388,7 +388,7 @@ class Console : public Serializable
     unique_ptr<AbstractFrameManager> myFrameManager;
 
     // The audio fragment queue that connects TIA and audio driver
-    unique_ptr<AudioQueue> myAudioQueue;
+    shared_ptr<AudioQueue> myAudioQueue;
 
     // Pointer to the Cartridge (the debugger needs it)
     unique_ptr<Cartridge> myCart;

src/emucore/Sound.hxx

@@ -51,7 +51,7 @@ class Sound
       Start the sound system, initializing it if necessary.  This must be
       called before any calls are made to derived methods.
     */
-    virtual void open(AudioQueue* audioQueue) = 0;
+    virtual void open(shared_ptr<AudioQueue> audioQueue) = 0;
 
     /**
       Should be called to stop the sound system.  Once called the sound

src/emucore/tia/Audio.cxx

@@ -53,7 +53,7 @@ void Audio::reset()
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void Audio::setAudioQueue(AudioQueue* queue)
+void Audio::setAudioQueue(shared_ptr<AudioQueue> queue)
 {
   myAudioQueue = queue;
 

src/emucore/tia/Audio.hxx

@@ -30,7 +30,7 @@ class Audio
 
     void reset();
 
-    void setAudioQueue(AudioQueue *queue);
+    void setAudioQueue(shared_ptr<AudioQueue> queue);
 
     void tick();
 
@@ -42,7 +42,7 @@ class Audio
     void phase1();
 
   private:
-    AudioQueue* myAudioQueue;
+    shared_ptr<AudioQueue> myAudioQueue;
 
     uInt8 myCounter;
 

src/emucore/tia/TIA.cxx

@@ -117,7 +117,7 @@ void TIA::setFrameManager(AbstractFrameManager *frameManager)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void TIA::setAudioQueue(AudioQueue* queue)
+void TIA::setAudioQueue(shared_ptr<AudioQueue> queue)
 {
   myAudio.setAudioQueue(queue);
 }

src/emucore/tia/TIA.hxx

@@ -114,7 +114,7 @@ class TIA : public Device
       Set the audio queue. This needs to be dynamic as the queue is created after
       the timing has been determined.
     */
-    void setAudioQueue(AudioQueue *audioQueue);
+    void setAudioQueue(shared_ptr<AudioQueue> audioQueue);
 
     /**
       Clear the configured frame manager and deteach the lifecycle callbacks.