mixer/Plugin: pass AudioOutput reference to init()

Passing a void pointer is unsafe.

src/mixer/MixerControl.cxx

@@ -26,7 +26,7 @@
 
 Mixer *
 mixer_new(EventLoop &event_loop,
-	  const MixerPlugin &plugin, void *ao,
+	  const MixerPlugin &plugin, AudioOutput &ao,
 	  const config_param &param,
 	  Error &error)
 {

src/mixer/MixerControl.hxx

@@ -28,11 +28,12 @@
 class Error;
 class Mixer;
 class EventLoop;
+struct AudioOutput;
 struct MixerPlugin;
 struct config_param;
 
 Mixer *
-mixer_new(EventLoop &event_loop, const MixerPlugin &plugin, void *ao,
+mixer_new(EventLoop &event_loop, const MixerPlugin &plugin, AudioOutput &ao,
 	  const config_param &param,
 	  Error &error);
 

src/mixer/MixerPlugin.hxx

@@ -28,6 +28,7 @@
 #define MPD_MIXER_PLUGIN_HXX
 
 struct config_param;
+struct AudioOutput;
 class Mixer;
 class EventLoop;
 class Error;
@@ -36,13 +37,13 @@ struct MixerPlugin {
 	/**
          * Alocates and configures a mixer device.
 	 *
-	 * @param ao the pointer returned by AudioOutputPlugin.init
+	 * @param ao the associated AudioOutput
 	 * @param param the configuration section
 	 * @param error_r location to store the error occurring, or
 	 * nullptr to ignore errors
 	 * @return a mixer object, or nullptr on error
 	 */
-	Mixer *(*init)(EventLoop &event_loop, void *ao,
+	Mixer *(*init)(EventLoop &event_loop, AudioOutput &ao,
 		       const config_param &param,
 		       Error &error);
 

src/mixer/plugins/AlsaMixerPlugin.cxx

@@ -167,7 +167,7 @@ AlsaMixer::Configure(const config_param &param)
 }
 
 static Mixer *
-alsa_mixer_init(EventLoop &event_loop, gcc_unused void *ao,
+alsa_mixer_init(EventLoop &event_loop, gcc_unused AudioOutput &ao,
 		const config_param &param,
 		gcc_unused Error &error)
 {

src/mixer/plugins/OssMixerPlugin.cxx

@@ -97,7 +97,7 @@ OssMixer::Configure(const config_param &param, Error &error)
 }
 
 static Mixer *
-oss_mixer_init(gcc_unused EventLoop &event_loop, gcc_unused void *ao,
+oss_mixer_init(gcc_unused EventLoop &event_loop, gcc_unused AudioOutput &ao,
 	       const config_param &param,
 	       Error &error)
 {

src/mixer/plugins/PulseMixerPlugin.cxx

@@ -35,13 +35,13 @@
 #include <assert.h>
 
 class PulseMixer final : public Mixer {
-	PulseOutput *output;
+	PulseOutput &output;
 
 	bool online;
 	struct pa_cvolume volume;
 
 public:
-	PulseMixer(PulseOutput *_output)
+	PulseMixer(PulseOutput &_output)
 		:Mixer(pulse_mixer_plugin),
 		output(_output), online(false)
 	{
@@ -130,7 +130,7 @@ PulseMixer::Update(pa_context *context, pa_stream *stream)
 }
 
 void
-pulse_mixer_on_connect(gcc_unused PulseMixer *pm,
+pulse_mixer_on_connect(gcc_unused PulseMixer &pm,
 		       struct pa_context *context)
 {
 	pa_operation *o;
@@ -151,41 +151,34 @@ pulse_mixer_on_connect(gcc_unused PulseMixer *pm,
 }
 
 void
-pulse_mixer_on_disconnect(PulseMixer *pm)
+pulse_mixer_on_disconnect(PulseMixer &pm)
 {
-	pm->Offline();
+	pm.Offline();
 }
 
 void
-pulse_mixer_on_change(PulseMixer *pm,
+pulse_mixer_on_change(PulseMixer &pm,
 		      struct pa_context *context, struct pa_stream *stream)
 {
-	pm->Update(context, stream);
+	pm.Update(context, stream);
 }
 
 static Mixer *
-pulse_mixer_init(gcc_unused EventLoop &event_loop, void *ao,
+pulse_mixer_init(gcc_unused EventLoop &event_loop, AudioOutput &ao,
 		 gcc_unused const config_param &param,
-		 Error &error)
+		 gcc_unused Error &error)
 {
-	PulseOutput *po = (PulseOutput *)ao;
+	PulseOutput &po = (PulseOutput &)ao;
-
-	if (ao == nullptr) {
-		error.Set(pulse_mixer_domain,
-			  "The pulse mixer cannot work without the audio output");
-		return nullptr;
-	}
-
 	PulseMixer *pm = new PulseMixer(po);
 
-	pulse_output_set_mixer(po, pm);
+	pulse_output_set_mixer(po, *pm);
 
 	return pm;
 }
 
 PulseMixer::~PulseMixer()
 {
-	pulse_output_clear_mixer(output, this);
+	pulse_output_clear_mixer(output, *this);
 }
 
 int

src/mixer/plugins/PulseMixerPlugin.hxx

@@ -25,12 +25,12 @@ struct pa_context;
 struct pa_stream;
 
 void
-pulse_mixer_on_connect(PulseMixer *pm, pa_context *context);
+pulse_mixer_on_connect(PulseMixer &pm, pa_context *context);
 
 void
-pulse_mixer_on_disconnect(PulseMixer *pm);
+pulse_mixer_on_disconnect(PulseMixer &pm);
 
 void
-pulse_mixer_on_change(PulseMixer *pm, pa_context *context, pa_stream *stream);
+pulse_mixer_on_change(PulseMixer &pm, pa_context *context, pa_stream *stream);
 
 #endif

src/mixer/plugins/RoarMixerPlugin.cxx

@@ -26,10 +26,10 @@
 
 class RoarMixer final : public Mixer {
 	/** the base mixer class */
-	RoarOutput *self;
+	RoarOutput &self;
 
 public:
-	RoarMixer(RoarOutput *_output)
+	RoarMixer(RoarOutput &_output)
 		:Mixer(roar_mixer_plugin),
 		self(_output) {}
 
@@ -46,11 +46,11 @@ public:
 };
 
 static Mixer *
-roar_mixer_init(gcc_unused EventLoop &event_loop, void *ao,
+roar_mixer_init(gcc_unused EventLoop &event_loop, AudioOutput &ao,
 		gcc_unused const config_param &param,
 		gcc_unused Error &error)
 {
-	return new RoarMixer((RoarOutput *)ao);
+	return new RoarMixer((RoarOutput &)ao);
 }
 
 int

src/mixer/plugins/SoftwareMixerPlugin.cxx

@@ -84,7 +84,8 @@ public:
 };
 
 static Mixer *
-software_mixer_init(gcc_unused EventLoop &event_loop, gcc_unused void *ao,
+software_mixer_init(gcc_unused EventLoop &event_loop,
+		    gcc_unused AudioOutput &ao,
 		    gcc_unused const config_param &param,
 		    gcc_unused Error &error)
 {

src/mixer/plugins/WinmmMixerPlugin.cxx

@@ -31,10 +31,10 @@
 #include <windows.h>
 
 class WinmmMixer final : public Mixer {
-	WinmmOutput *output;
+	WinmmOutput &output;
 
 public:
-	WinmmMixer(WinmmOutput *_output)
+	WinmmMixer(WinmmOutput &_output)
 		:Mixer(winmm_mixer_plugin),
 		output(_output) {
 	}
@@ -67,13 +67,11 @@ winmm_volume_encode(int volume)
 }
 
 static Mixer *
-winmm_mixer_init(gcc_unused EventLoop &event_loop, void *ao,
+winmm_mixer_init(gcc_unused EventLoop &event_loop, AudioOutput &ao,
 		 gcc_unused const config_param &param,
 		 gcc_unused Error &error)
 {
-	assert(ao != nullptr);
+	return new WinmmMixer((WinmmOutput &)ao);
-
-	return new WinmmMixer((WinmmOutput *)ao);
 }
 
 int

src/output/Init.cxx

@@ -129,10 +129,10 @@ audio_output_load_mixer(EventLoop &event_loop, AudioOutput *ao,
 		if (plugin == nullptr)
 			return nullptr;
 
-		return mixer_new(event_loop, *plugin, ao, param, error);
+		return mixer_new(event_loop, *plugin, *ao, param, error);
 
 	case MIXER_TYPE_SOFTWARE:
-		mixer = mixer_new(event_loop, software_mixer_plugin, nullptr,
+		mixer = mixer_new(event_loop, software_mixer_plugin, *ao,
 				  config_param(),
 				  IgnoreError());
 		assert(mixer != nullptr);

src/output/plugins/PulseOutputPlugin.cxx

@@ -70,70 +70,66 @@ SetError(Error &error, pa_context *context, const char *msg)
 }
 
 void
-pulse_output_lock(PulseOutput *po)
+pulse_output_lock(PulseOutput &po)
 {
-	pa_threaded_mainloop_lock(po->mainloop);
+	pa_threaded_mainloop_lock(po.mainloop);
 }
 
 void
-pulse_output_unlock(PulseOutput *po)
+pulse_output_unlock(PulseOutput &po)
 {
-	pa_threaded_mainloop_unlock(po->mainloop);
+	pa_threaded_mainloop_unlock(po.mainloop);
 }
 
 void
-pulse_output_set_mixer(PulseOutput *po, PulseMixer *pm)
+pulse_output_set_mixer(PulseOutput &po, PulseMixer &pm)
 {
-	assert(po != nullptr);
+	assert(po.mixer == nullptr);
-	assert(po->mixer == nullptr);
-	assert(pm != nullptr);
 
-	po->mixer = pm;
+	po.mixer = ±
 
-	if (po->mainloop == nullptr)
+	if (po.mainloop == nullptr)
 		return;
 
-	pa_threaded_mainloop_lock(po->mainloop);
+	pa_threaded_mainloop_lock(po.mainloop);
 
-	if (po->context != nullptr &&
+	if (po.context != nullptr &&
-	    pa_context_get_state(po->context) == PA_CONTEXT_READY) {
+	    pa_context_get_state(po.context) == PA_CONTEXT_READY) {
-		pulse_mixer_on_connect(pm, po->context);
+		pulse_mixer_on_connect(pm, po.context);
 
-		if (po->stream != nullptr &&
+		if (po.stream != nullptr &&
-		    pa_stream_get_state(po->stream) == PA_STREAM_READY)
+		    pa_stream_get_state(po.stream) == PA_STREAM_READY)
-			pulse_mixer_on_change(pm, po->context, po->stream);
+			pulse_mixer_on_change(pm, po.context, po.stream);
 	}
 
-	pa_threaded_mainloop_unlock(po->mainloop);
+	pa_threaded_mainloop_unlock(po.mainloop);
 }
 
 void
-pulse_output_clear_mixer(PulseOutput *po, gcc_unused PulseMixer *pm)
+pulse_output_clear_mixer(PulseOutput &po, gcc_unused PulseMixer &pm)
 {
-	assert(po != nullptr);
+	assert(po.mixer == &pm);
-	assert(pm != nullptr);
-	assert(po->mixer == pm);
 
-	po->mixer = nullptr;
+	po.mixer = nullptr;
 }
 
 bool
-pulse_output_set_volume(PulseOutput *po, const pa_cvolume *volume,
+pulse_output_set_volume(PulseOutput &po, const pa_cvolume *volume,
 			Error &error)
 {
 	pa_operation *o;
 
-	if (po->context == nullptr || po->stream == nullptr ||
+	if (po.context == nullptr || po.stream == nullptr ||
-	    pa_stream_get_state(po->stream) != PA_STREAM_READY) {
+	    pa_stream_get_state(po.stream) != PA_STREAM_READY) {
 		error.Set(pulse_output_domain, "disconnected");
 		return false;
 	}
 
-	o = pa_context_set_sink_input_volume(po->context,
+	o = pa_context_set_sink_input_volume(po.context,
-					     pa_stream_get_index(po->stream),
+					     pa_stream_get_index(po.stream),
 					     volume, nullptr, nullptr);
 	if (o == nullptr) {
-		SetError(error, po->context,
+		SetError(error, po.context,
 			 "failed to set PulseAudio volume");
 		return false;
 	}
@@ -190,7 +186,7 @@ pulse_output_context_state_cb(struct pa_context *context, void *userdata)
 	switch (pa_context_get_state(context)) {
 	case PA_CONTEXT_READY:
 		if (po->mixer != nullptr)
-			pulse_mixer_on_connect(po->mixer, context);
+			pulse_mixer_on_connect(*po->mixer, context);
 
 		pa_threaded_mainloop_signal(po->mainloop, 0);
 		break;
@@ -198,7 +194,7 @@ pulse_output_context_state_cb(struct pa_context *context, void *userdata)
 	case PA_CONTEXT_TERMINATED:
 	case PA_CONTEXT_FAILED:
 		if (po->mixer != nullptr)
-			pulse_mixer_on_disconnect(po->mixer);
+			pulse_mixer_on_disconnect(*po->mixer);
 
 		/* the caller thread might be waiting for these
 		   states */
@@ -231,7 +227,7 @@ pulse_output_subscribe_cb(pa_context *context,
 	    idx == pa_stream_get_index(po->stream) &&
 	    (type == PA_SUBSCRIPTION_EVENT_NEW ||
 	     type == PA_SUBSCRIPTION_EVENT_CHANGE))
-		pulse_mixer_on_change(po->mixer, context, po->stream);
+		pulse_mixer_on_change(*po->mixer, context, po->stream);
 }
 
 /**
@@ -487,7 +483,7 @@ pulse_output_stream_state_cb(pa_stream *stream, void *userdata)
 	switch (pa_stream_get_state(stream)) {
 	case PA_STREAM_READY:
 		if (po->mixer != nullptr)
-			pulse_mixer_on_change(po->mixer, po->context, stream);
+			pulse_mixer_on_change(*po->mixer, po->context, stream);
 
 		pa_threaded_mainloop_signal(po->mainloop, 0);
 		break;
@@ -495,7 +491,7 @@ pulse_output_stream_state_cb(pa_stream *stream, void *userdata)
 	case PA_STREAM_FAILED:
 	case PA_STREAM_TERMINATED:
 		if (po->mixer != nullptr)
-			pulse_mixer_on_disconnect(po->mixer);
+			pulse_mixer_on_disconnect(*po->mixer);
 
 		pa_threaded_mainloop_signal(po->mainloop, 0);
 		break;

src/output/plugins/PulseOutputPlugin.hxx

@@ -28,19 +28,19 @@ class Error;
 extern const struct AudioOutputPlugin pulse_output_plugin;
 
 void
-pulse_output_lock(PulseOutput *po);
+pulse_output_lock(PulseOutput &po);
 
 void
-pulse_output_unlock(PulseOutput *po);
+pulse_output_unlock(PulseOutput &po);
 
 void
-pulse_output_set_mixer(PulseOutput *po, PulseMixer *pm);
+pulse_output_set_mixer(PulseOutput &po, PulseMixer &pm);
 
 void
-pulse_output_clear_mixer(PulseOutput *po, PulseMixer *pm);
+pulse_output_clear_mixer(PulseOutput &po, PulseMixer &pm);
 
 bool
-pulse_output_set_volume(PulseOutput *po,
+pulse_output_set_volume(PulseOutput &po,
 			const pa_cvolume *volume, Error &error);
 
 #endif

src/output/plugins/RoarOutputPlugin.cxx

@@ -93,9 +93,9 @@ RoarOutput::GetVolume() const
 }
 
 int
-roar_output_get_volume(RoarOutput *roar)
+roar_output_get_volume(RoarOutput &roar)
 {
-	return roar->GetVolume();
+	return roar.GetVolume();
 }
 
 bool
@@ -115,9 +115,9 @@ RoarOutput::SetVolume(unsigned volume)
 }
 
 bool
-roar_output_set_volume(RoarOutput *roar, unsigned volume)
+roar_output_set_volume(RoarOutput &roar, unsigned volume)
 {
-	return roar->SetVolume(volume);
+	return roar.SetVolume(volume);
 }
 
 inline void

src/output/plugins/RoarOutputPlugin.hxx

@@ -25,9 +25,9 @@ class RoarOutput;
 extern const struct AudioOutputPlugin roar_output_plugin;
 
 int
-roar_output_get_volume(RoarOutput *roar);
+roar_output_get_volume(RoarOutput &roar);
 
 bool
-roar_output_set_volume(RoarOutput *roar, unsigned volume);
+roar_output_set_volume(RoarOutput &roar, unsigned volume);
 
 #endif

src/output/plugins/WinmmOutputPlugin.cxx

@@ -59,9 +59,9 @@ struct WinmmOutput {
 static constexpr Domain winmm_output_domain("winmm_output");
 
 HWAVEOUT
-winmm_output_get_handle(WinmmOutput *output)
+winmm_output_get_handle(WinmmOutput &output)
 {
-	return output->handle;
+	return output.handle;
 }
 
 static bool

src/output/plugins/WinmmOutputPlugin.hxx

@@ -35,7 +35,7 @@ extern const struct AudioOutputPlugin winmm_output_plugin;
 
 gcc_pure
 HWAVEOUT
-winmm_output_get_handle(WinmmOutput *);
+winmm_output_get_handle(WinmmOutput &output);
 
 #endif
 

test/read_mixer.cxx

@@ -35,59 +35,6 @@
 #include <string.h>
 #include <unistd.h>
 
-#ifdef HAVE_PULSE
-#include "output/plugins/PulseOutputPlugin.hxx"
-
-void
-pulse_output_lock(gcc_unused PulseOutput *po)
-{
-}
-
-void
-pulse_output_unlock(gcc_unused PulseOutput *po)
-{
-}
-
-void
-pulse_output_set_mixer(gcc_unused PulseOutput *po,
-		       gcc_unused PulseMixer *pm)
-{
-}
-
-void
-pulse_output_clear_mixer(gcc_unused PulseOutput *po,
-			 gcc_unused PulseMixer *pm)
-{
-}
-
-bool
-pulse_output_set_volume(gcc_unused PulseOutput *po,
-			gcc_unused const struct pa_cvolume *volume,
-			gcc_unused Error &error)
-{
-	return false;
-}
-
-#endif
-
-#ifdef HAVE_ROAR
-#include "output/plugins/RoarOutputPlugin.hxx"
-
-int
-roar_output_get_volume(gcc_unused RoarOutput *roar)
-{
-	return -1;
-}
-
-bool
-roar_output_set_volume(gcc_unused RoarOutput *roar,
-		       gcc_unused unsigned volume)
-{
-	return true;
-}
-
-#endif
-
 void
 GlobalEvents::Emit(gcc_unused Event event)
 {
@@ -116,7 +63,8 @@ int main(int argc, gcc_unused char **argv)
 	EventLoop event_loop;
 
 	Error error;
-	Mixer *mixer = mixer_new(event_loop, alsa_mixer_plugin, nullptr,
+	Mixer *mixer = mixer_new(event_loop, alsa_mixer_plugin,
+				 *(AudioOutput *)nullptr,
 				 config_param(), error);
 	if (mixer == NULL) {
 		LogError(error, "mixer_new() failed");