improved port cleanup as backend is destroyed

libs/backends/alsa/alsa_audiobackend.cc

@@ -89,6 +89,8 @@ AlsaAudioBackend::AlsaAudioBackend (AudioEngine& e, AudioBackendInfo& info)
 
 AlsaAudioBackend::~AlsaAudioBackend ()
 {
+	clear_ports ();
+
 	pthread_mutex_destroy (&_port_callback_mutex);
 	pthread_mutex_destroy (&_device_port_mutex);
 }

libs/backends/coreaudio/coreaudio_backend.cc

@@ -129,6 +129,9 @@ CoreAudioBackend::~CoreAudioBackend ()
 {
 	delete _pcmio; _pcmio = 0;
 	delete _midiio; _midiio = 0;
+
+	clear_ports ();
+
 	pthread_mutex_destroy (&_port_callback_mutex);
 	pthread_mutex_destroy (&_port_registration_mutex);
 	pthread_mutex_destroy (&_process_callback_mutex);

libs/backends/jack/jack_audiobackend.cc

@@ -72,6 +72,7 @@ JACKAudioBackend::JACKAudioBackend (AudioEngine& e, AudioBackendInfo& info, boos
 
 JACKAudioBackend::~JACKAudioBackend()
 {
+	_jack_ports.clear ();
 }
 
 string

libs/backends/portaudio/portaudio_backend.cc

@@ -106,6 +106,8 @@ PortAudioBackend::~PortAudioBackend ()
 	delete _pcmio; _pcmio = 0;
 	delete _midiio; _midiio = 0;
 
+	clear_ports ();
+
 	pthread_mutex_destroy (&_port_callback_mutex);
 	pthread_mutex_destroy (&_freewheel_mutex);
 	pthread_cond_destroy (&_freewheel_signal);

libs/backends/pulseaudio/pulseaudio_backend.cc

@@ -69,6 +69,8 @@ PulseAudioBackend::PulseAudioBackend (AudioEngine& e, AudioBackendInfo& info)
 
 PulseAudioBackend::~PulseAudioBackend ()
 {
+	clear_ports ();
+
 	pthread_mutex_destroy (&_port_callback_mutex);
 }