fix crash when copy'ing latent plugins
[ardour.git] / libs / ardour / audioengine.cc
index cb167c959579dfddc96348fca598fae5e3b6b707..30c2113c06ad39fe7e23d3f695e985c3586e7db1 100644 (file)
@@ -23,6 +23,7 @@
 #include <exception>
 #include <stdexcept>
 #include <sstream>
+#include <cmath>
 
 #include <glibmm/timer.h>
 #include <glibmm/pattern.h>
 #include "ardour/audio_port.h"
 #include "ardour/audio_backend.h"
 #include "ardour/audioengine.h"
-#include "ardour/backend_search_path.h"
+#include "ardour/search_paths.h"
 #include "ardour/buffer.h"
 #include "ardour/cycle_timer.h"
 #include "ardour/internal_send.h"
 #include "ardour/meter.h"
 #include "ardour/midi_port.h"
 #include "ardour/midiport_manager.h"
+#include "ardour/mididm.h"
 #include "ardour/mtdm.h"
 #include "ardour/port.h"
 #include "ardour/process_thread.h"
 #include "ardour/session.h"
 
-#include "i18n.h"
+#include "pbd/i18n.h"
 
 using namespace std;
 using namespace ARDOUR;
 using namespace PBD;
 
-gint AudioEngine::m_meter_exit;
 AudioEngine* AudioEngine::_instance = 0;
 
+static gint audioengine_thread_cnt = 1;
+
+#ifdef SILENCE_AFTER
+#define SILENCE_AFTER_SECONDS 600
+#endif
+
 AudioEngine::AudioEngine ()
        : session_remove_pending (false)
        , session_removal_countdown (-1)
@@ -73,23 +80,41 @@ AudioEngine::AudioEngine ()
        , m_meter_thread (0)
        , _main_thread (0)
        , _mtdm (0)
-       , _measuring_latency (false)
+       , _mididm (0)
+       , _measuring_latency (MeasureNone)
        , _latency_input_port (0)
        , _latency_output_port (0)
        , _latency_flush_frames (0)
        , _latency_signal_latency (0)
        , _stopped_for_latency (false)
+       , _started_for_latency (false)
        , _in_destructor (false)
+       , _last_backend_error_string(AudioBackend::get_error_string((AudioBackend::ErrorCode)-1))
+    , _hw_reset_event_thread(0)
+    , _hw_reset_request_count(0)
+    , _stop_hw_reset_processing(0)
+    , _hw_devicelist_update_thread(0)
+    , _hw_devicelist_update_count(0)
+    , _stop_hw_devicelist_processing(0)
+#ifdef SILENCE_AFTER_SECONDS
+       , _silence_countdown (0)
+       , _silence_hit_cnt (0)
+#endif
 {
-       g_atomic_int_set (&m_meter_exit, 0);
+       reset_silence_countdown ();
+       start_hw_event_processing();
        discover_backends ();
 }
 
 AudioEngine::~AudioEngine ()
 {
        _in_destructor = true;
-       stop_metering_thread ();
+       stop_hw_event_processing();
        drop_backend ();
+       for (BackendMap::const_iterator i = _backends.begin(); i != _backends.end(); ++i) {
+               i->second->deinstantiate();
+       }
+       delete _main_thread;
 }
 
 AudioEngine*
@@ -100,25 +125,8 @@ AudioEngine::create ()
        }
 
        _instance = new AudioEngine ();
-       
-       return _instance;
-}
-
-void
-_thread_init_callback (void * /*arg*/)
-{
-       /* make sure that anybody who needs to know about this thread
-          knows about it.
-       */
-
-       pthread_set_name (X_("audioengine"));
-
-       PBD::notify_gui_about_thread_creation ("gui", pthread_self(), X_("Audioengine"), 4096);
-       PBD::notify_gui_about_thread_creation ("midiui", pthread_self(), X_("Audioengine"), 128);
 
-       SessionEvent::create_per_thread_pool (X_("Audioengine"), 512);
-
-       AsyncMIDIPort::set_process_thread (pthread_self());
+       return _instance;
 }
 
 void
@@ -151,10 +159,14 @@ AudioEngine::sample_rate_change (pframes_t nframes)
 
        SampleRateChanged (nframes); /* EMIT SIGNAL */
 
+#ifdef SILENCE_AFTER_SECONDS
+       _silence_countdown = nframes * SILENCE_AFTER_SECONDS;
+#endif
+
        return 0;
 }
 
-int 
+int
 AudioEngine::buffer_size_change (pframes_t bufsiz)
 {
        if (_session) {
@@ -162,12 +174,17 @@ AudioEngine::buffer_size_change (pframes_t bufsiz)
                last_monitor_check = 0;
        }
 
+       BufferSizeChanged (bufsiz); /* EMIT SIGNAL */
+
        return 0;
 }
 
 /** Method called by our ::process_thread when there is work to be done.
  *  @param nframes Number of frames to process.
  */
+#ifdef __clang__
+__attribute__((annotate("realtime")))
+#endif
 int
 AudioEngine::process_callback (pframes_t nframes)
 {
@@ -189,20 +206,48 @@ AudioEngine::process_callback (pframes_t nframes)
 
        if (!tm.locked()) {
                /* return having done nothing */
-               _processed_frames = next_processed_frames;
+               if (_session) {
+                       Xrun();
+               }
+               /* really only JACK requires this
+                * (other backends clear the output buffers
+                * before the process_callback. it may even be
+                * jack/alsa only). but better safe than sorry.
+                */
+               PortManager::silence_outputs (nframes);
                return 0;
        }
 
+       /* The coreaudio-backend calls thread_init_callback() if
+        * the hardware changes or pthread_self() changes.
+        *
+        * However there are cases when neither holds true, yet
+        * the thread-pool changes: e.g. connect a headphone to
+        * a shared mic/headphone jack.
+        * It's probably related to, or caused by clocksource changes.
+        *
+        * For reasons yet unknown Glib::Threads::Private() can
+        * use a different thread-private in the same pthread
+        * (coreaudio render callback).
+        *
+        * Coreaudio must set something which influences
+        * pthread_key_t uniqness or reset the key using
+        * pthread_getspecific().
+        */
+       if (! SessionEvent::has_per_thread_pool ()) {
+               thread_init_callback (NULL);
+       }
+
        bool return_after_remove_check = false;
 
-       if (_measuring_latency && _mtdm) {
+       if (_measuring_latency == MeasureAudio && _mtdm) {
                /* run a normal cycle from the perspective of the PortManager
                   so that we get silence on all registered ports.
-                  
+
                   we overwrite the silence on the two ports used for latency
                   measurement.
                */
-               
+
                PortManager::cycle_start (nframes);
                PortManager::silence (nframes);
 
@@ -218,8 +263,30 @@ AudioEngine::process_callback (pframes_t nframes)
                PortManager::cycle_end (nframes);
                return_after_remove_check = true;
 
+       } else if (_measuring_latency == MeasureMIDI && _mididm) {
+               /* run a normal cycle from the perspective of the PortManager
+                  so that we get silence on all registered ports.
+
+                  we overwrite the silence on the two ports used for latency
+                  measurement.
+               */
+
+               PortManager::cycle_start (nframes);
+               PortManager::silence (nframes);
+
+               if (_latency_input_port && _latency_output_port) {
+                       PortEngine& pe (port_engine());
+
+                       _mididm->process (nframes, pe,
+                                       pe.get_buffer (_latency_input_port, nframes),
+                                       pe.get_buffer (_latency_output_port, nframes));
+               }
+
+               PortManager::cycle_end (nframes);
+               return_after_remove_check = true;
+
        } else if (_latency_flush_frames) {
-               
+
                /* wait for the appropriate duration for the MTDM signal to
                 * drain from the ports before we revert to normal behaviour.
                 */
@@ -227,7 +294,7 @@ AudioEngine::process_callback (pframes_t nframes)
                PortManager::cycle_start (nframes);
                PortManager::silence (nframes);
                PortManager::cycle_end (nframes);
-               
+
                 if (_latency_flush_frames > nframes) {
                         _latency_flush_frames -= nframes;
                 } else {
@@ -245,18 +312,18 @@ AudioEngine::process_callback (pframes_t nframes)
 
                        /* fade out over 1 second */
                        session_removal_countdown = sample_rate()/2;
-                       session_removal_gain = 1.0;
+                       session_removal_gain = GAIN_COEFF_UNITY;
                        session_removal_gain_step = 1.0/session_removal_countdown;
 
                } else if (session_removal_countdown > 0) {
 
                        /* we'll be fading audio out.
-                          
-                          if this is the last time we do this as part 
+
+                          if this is the last time we do this as part
                           of session removal, do a MIDI panic now
                           to get MIDI stopped. This relies on the fact
                           that "immediate data" (aka "out of band data") from
-                          MIDI tracks is *appended* after any other data, 
+                          MIDI tracks is *appended* after any other data,
                           so that it emerges after any outbound note ons, etc.
                        */
 
@@ -303,14 +370,13 @@ AudioEngine::process_callback (pframes_t nframes)
        */
 
        if (_freewheeling && !Freewheel.empty()) {
-                Freewheel (nframes);
+               Freewheel (nframes);
        } else {
-               if (_session) {
-                       _session->process (nframes);
-               }
+               _session->process (nframes);
        }
 
        if (_freewheeling) {
+               PortManager::cycle_end (nframes);
                return 0;
        }
 
@@ -320,19 +386,40 @@ AudioEngine::process_callback (pframes_t nframes)
        }
 
        if (last_monitor_check + monitor_check_interval < next_processed_frames) {
-               
+
                PortManager::check_monitoring ();
                last_monitor_check = next_processed_frames;
        }
 
-       if (_session->silent()) {
+#ifdef SILENCE_AFTER_SECONDS
+
+       bool was_silent = (_silence_countdown == 0);
+
+       if (_silence_countdown >= nframes) {
+               _silence_countdown -= nframes;
+       } else {
+               _silence_countdown = 0;
+       }
+
+       if (!was_silent && _silence_countdown == 0) {
+               _silence_hit_cnt++;
+               BecameSilent (); /* EMIT SIGNAL */
+       }
+
+       if (_silence_countdown == 0 || _session->silent()) {
                PortManager::silence (nframes);
        }
 
+#else
+       if (_session->silent()) {
+               PortManager::silence (nframes, _session);
+       }
+#endif
+
        if (session_remove_pending && session_removal_countdown) {
 
                PortManager::fade_out (session_removal_gain, session_removal_gain_step, nframes);
-               
+
                if (session_removal_countdown > nframes) {
                        session_removal_countdown -= nframes;
                } else {
@@ -347,43 +434,173 @@ AudioEngine::process_callback (pframes_t nframes)
        _processed_frames = next_processed_frames;
 
        PT_TIMING_CHECK (2);
-       
+
        return 0;
 }
 
+void
+AudioEngine::reset_silence_countdown ()
+{
+#ifdef SILENCE_AFTER_SECONDS
+       double sr = 48000; /* default in case there is no backend */
+
+       sr = sample_rate();
+
+       _silence_countdown = max (60 * sr, /* 60 seconds */
+                                 sr * (SILENCE_AFTER_SECONDS / ::pow (2.0, (double) _silence_hit_cnt)));
+
+#endif
+}
 
 void
-AudioEngine::stop_metering_thread ()
+AudioEngine::launch_device_control_app()
 {
-       if (m_meter_thread) {
-               g_atomic_int_set (&m_meter_exit, 1);
-               m_meter_thread->join ();
-               m_meter_thread = 0;
+       if (_state_lock.trylock () ) {
+               _backend->launch_control_app ();
+               _state_lock.unlock ();
        }
 }
 
+
 void
-AudioEngine::start_metering_thread ()
+AudioEngine::request_backend_reset()
 {
-       if (m_meter_thread == 0) {
-               g_atomic_int_set (&m_meter_exit, 0);
-               m_meter_thread = Glib::Threads::Thread::create (boost::bind (&AudioEngine::meter_thread, this));
-       }
+    Glib::Threads::Mutex::Lock guard (_reset_request_lock);
+    g_atomic_int_inc (&_hw_reset_request_count);
+    _hw_reset_condition.signal ();
+}
+
+int
+AudioEngine::backend_reset_requested()
+{
+       return g_atomic_int_get (&_hw_reset_request_count);
 }
 
 void
-AudioEngine::meter_thread ()
+AudioEngine::do_reset_backend()
 {
-       pthread_set_name (X_("meter"));
+       SessionEvent::create_per_thread_pool (X_("Backend reset processing thread"), 1024);
+
+       Glib::Threads::Mutex::Lock guard (_reset_request_lock);
+
+       while (!_stop_hw_reset_processing) {
+
+               if (g_atomic_int_get (&_hw_reset_request_count) != 0 && _backend) {
+
+                       _reset_request_lock.unlock();
+
+                       Glib::Threads::RecMutex::Lock pl (_state_lock);
+                       g_atomic_int_dec_and_test (&_hw_reset_request_count);
+
+            std::cout << "AudioEngine::RESET::Reset request processing. Requests left: " << _hw_reset_request_count << std::endl;
+                        DeviceResetStarted(); // notify about device reset to be started
+
+                        // backup the device name
+                        std::string name = _backend->device_name ();
+
+            std::cout << "AudioEngine::RESET::Reseting device..." << std::endl;
+                       if ( ( 0 == stop () ) &&
+                 ( 0 == _backend->reset_device () ) &&
+                 ( 0 == start () ) ) {
+
+                               std::cout << "AudioEngine::RESET::Engine started..." << std::endl;
+
+                               // inform about possible changes
+                               BufferSizeChanged (_backend->buffer_size() );
+                DeviceResetFinished(); // notify about device reset finish
+
+            } else {
+
+                DeviceResetFinished(); // notify about device reset finish
+                               // we've got an error
+                DeviceError();
+                       }
+
+                       std::cout << "AudioEngine::RESET::Done." << std::endl;
+
+                       _reset_request_lock.lock();
+
+               } else {
+
+                       _hw_reset_condition.wait (_reset_request_lock);
 
-       while (true) {
-               Glib::usleep (10000); /* 1/100th sec interval */
-               if (g_atomic_int_get(&m_meter_exit)) {
-                       break;
                }
-               Metering::Meter ();
        }
 }
+void
+AudioEngine::request_device_list_update()
+{
+    Glib::Threads::Mutex::Lock guard (_devicelist_update_lock);
+    g_atomic_int_inc (&_hw_devicelist_update_count);
+    _hw_devicelist_update_condition.signal ();
+}
+
+
+void
+AudioEngine::do_devicelist_update()
+{
+    SessionEvent::create_per_thread_pool (X_("Device list update processing thread"), 512);
+
+    Glib::Threads::Mutex::Lock guard (_devicelist_update_lock);
+
+    while (!_stop_hw_devicelist_processing) {
+
+        if (_hw_devicelist_update_count) {
+
+            _devicelist_update_lock.unlock();
+
+            Glib::Threads::RecMutex::Lock pl (_state_lock);
+
+            g_atomic_int_dec_and_test (&_hw_devicelist_update_count);
+            DeviceListChanged (); /* EMIT SIGNAL */
+
+            _devicelist_update_lock.lock();
+
+        } else {
+            _hw_devicelist_update_condition.wait (_devicelist_update_lock);
+        }
+    }
+}
+
+
+void
+AudioEngine::start_hw_event_processing()
+{
+    if (_hw_reset_event_thread == 0) {
+        g_atomic_int_set(&_hw_reset_request_count, 0);
+        g_atomic_int_set(&_stop_hw_reset_processing, 0);
+        _hw_reset_event_thread = Glib::Threads::Thread::create (boost::bind (&AudioEngine::do_reset_backend, this));
+    }
+
+    if (_hw_devicelist_update_thread == 0) {
+        g_atomic_int_set(&_hw_devicelist_update_count, 0);
+        g_atomic_int_set(&_stop_hw_devicelist_processing, 0);
+        _hw_devicelist_update_thread = Glib::Threads::Thread::create (boost::bind (&AudioEngine::do_devicelist_update, this));
+    }
+}
+
+
+void
+AudioEngine::stop_hw_event_processing()
+{
+    if (_hw_reset_event_thread) {
+        g_atomic_int_set(&_stop_hw_reset_processing, 1);
+        g_atomic_int_set(&_hw_reset_request_count, 0);
+        _hw_reset_condition.signal ();
+        _hw_reset_event_thread->join ();
+        _hw_reset_event_thread = 0;
+    }
+
+    if (_hw_devicelist_update_thread) {
+        g_atomic_int_set(&_stop_hw_devicelist_processing, 1);
+        g_atomic_int_set(&_hw_devicelist_update_count, 0);
+        _hw_devicelist_update_condition.signal ();
+        _hw_devicelist_update_thread->join ();
+        _hw_devicelist_update_thread = 0;
+    }
+
+}
+
 
 void
 AudioEngine::set_session (Session *s)
@@ -420,7 +637,8 @@ AudioEngine::remove_session ()
 
                if (_session) {
                        session_remove_pending = true;
-                       session_removal_countdown = 0;
+                       /* signal the start of the fade out countdown */
+                       session_removal_countdown = -1;
                        session_removed.wait(_process_lock);
                }
 
@@ -433,13 +651,21 @@ AudioEngine::remove_session ()
 
 
 void
-AudioEngine::died ()
+AudioEngine::reconnect_session_routes (bool reconnect_inputs, bool reconnect_outputs)
 {
-        /* called from a signal handler for SIGPIPE */
+#ifdef USE_TRACKS_CODE_FEATURES
+       if (_session) {
+               _session->reconnect_existing_routes(true, true, reconnect_inputs, reconnect_outputs);
+       }
+#endif
+}
 
-       stop_metering_thread ();
 
-        _running = false;
+void
+AudioEngine::died ()
+{
+       /* called from a signal handler for SIGPIPE */
+       _running = false;
 }
 
 int
@@ -482,34 +708,46 @@ AudioEngine::discover_backends ()
 #else
        Glib::PatternSpec dll_extension_pattern("*backend.dll");
 #endif
-       
-       find_matching_files_in_search_path (backend_search_path (),
-                                           so_extension_pattern, backend_modules);
 
-       find_matching_files_in_search_path (backend_search_path (),
-                                           dylib_extension_pattern, backend_modules);
+       find_files_matching_pattern (backend_modules, backend_search_path (),
+                                    so_extension_pattern);
+
+       find_files_matching_pattern (backend_modules, backend_search_path (),
+                                    dylib_extension_pattern);
 
-       find_matching_files_in_search_path (backend_search_path (),
-                                           dll_extension_pattern, backend_modules);
+       find_files_matching_pattern (backend_modules, backend_search_path (),
+                                    dll_extension_pattern);
 
-       DEBUG_TRACE (DEBUG::Panning, string_compose (_("looking for backends in %1\n"), backend_search_path().to_string()));
+       DEBUG_TRACE (DEBUG::AudioEngine, string_compose ("looking for backends in %1\n", backend_search_path().to_string()));
 
        for (vector<std::string>::iterator i = backend_modules.begin(); i != backend_modules.end(); ++i) {
 
                AudioBackendInfo* info;
 
+               DEBUG_TRACE (DEBUG::AudioEngine, string_compose ("Checking possible backend in %1\n", *i));
+
                if ((info = backend_discover (*i)) != 0) {
                        _backends.insert (make_pair (info->name, info));
                }
        }
 
+       DEBUG_TRACE (DEBUG::AudioEngine, string_compose ("Found %1 backends\n", _backends.size()));
+
        return _backends.size();
 }
 
 AudioBackendInfo*
 AudioEngine::backend_discover (const string& path)
 {
+#ifdef PLATFORM_WINDOWS
+       // do not show popup dialog (e.g. missing libjack.dll)
+       // win7+ should use SetThreadErrorMode()
+       SetErrorMode(SEM_FAILCRITICALERRORS);
+#endif
        Glib::Module module (path);
+#ifdef PLATFORM_WINDOWS
+       SetErrorMode(0); // reset to system default
+#endif
        AudioBackendInfo* info;
        AudioBackendInfo* (*dfunc)(void);
        void* func = 0;
@@ -519,18 +757,21 @@ AudioEngine::backend_discover (const string& path)
                                        Glib::Module::get_last_error()) << endmsg;
                return 0;
        }
-       
+
        if (!module.get_symbol ("descriptor", func)) {
                error << string_compose(_("AudioEngine: backend at \"%1\" has no descriptor function."), path) << endmsg;
                error << Glib::Module::get_last_error() << endmsg;
                return 0;
        }
 
-       module.make_resident ();
-       
        dfunc = (AudioBackendInfo* (*)(void))func;
        info = dfunc();
-       
+       if (!info->available()) {
+               return 0;
+       }
+
+       module.make_resident ();
+
        return info;
 }
 
@@ -538,7 +779,7 @@ vector<const AudioBackendInfo*>
 AudioEngine::available_backends() const
 {
        vector<const AudioBackendInfo*> r;
-       
+
        for (BackendMap::const_iterator i = _backends.begin(); i != _backends.end(); ++i) {
                r.push_back (i->second);
        }
@@ -551,7 +792,7 @@ AudioEngine::current_backend_name() const
 {
        if (_backend) {
                return _backend->name();
-       } 
+       }
        return string();
 }
 
@@ -560,7 +801,11 @@ AudioEngine::drop_backend ()
 {
        if (_backend) {
                _backend->stop ();
+               // Stopped is needed for Graph to explicitly terminate threads
+               Stopped (); /* EMIT SIGNAL */
+               _backend->drop_device ();
                _backend.reset ();
+               _running = false;
        }
 }
 
@@ -584,7 +829,7 @@ AudioEngine::set_backend (const std::string& name, const std::string& arg1, cons
        }
 
        drop_backend ();
-       
+
        try {
                if (b->second->instantiate (arg1, arg2)) {
                        throw failed_constructor ();
@@ -615,57 +860,86 @@ AudioEngine::start (bool for_latency)
 
        _processed_frames = 0;
        last_monitor_check = 0;
-       
-       if (_backend->start (for_latency)) {
+
+       int error_code = _backend->start (for_latency);
+
+       if (error_code != 0) {
+               _last_backend_error_string =
+                   AudioBackend::get_error_string((AudioBackend::ErrorCode)error_code);
                return -1;
        }
 
        _running = true;
-       
+
        if (_session) {
                _session->set_frame_rate (_backend->sample_rate());
-               
+
                if (_session->config.get_jack_time_master()) {
                        _backend->set_time_master (true);
                }
+
        }
-       
-       start_metering_thread ();
-       
+
        if (!for_latency) {
                Running(); /* EMIT SIGNAL */
        }
-       
+
        return 0;
 }
 
 int
 AudioEngine::stop (bool for_latency)
 {
+       bool stop_engine = true;
+
        if (!_backend) {
                return 0;
        }
 
-       Glib::Threads::Mutex::Lock lm (_process_lock);
+       Glib::Threads::Mutex::Lock pl (_process_lock, Glib::Threads::NOT_LOCK);
 
-       if (_backend->stop ()) {
-               return -1;
+       if (running()) {
+               pl.acquire ();
+       }
+
+       if (for_latency && _backend->can_change_systemic_latency_when_running()) {
+               stop_engine = false;
+       } else {
+               if (_backend->stop ()) {
+                       pl.release ();
+                       return -1;
+               }
+       }
+
+       if (pl.locked ()) {
+               pl.release ();
+       }
+
+       if (_session && _running && stop_engine &&
+           (_session->state_of_the_state() & Session::Loading) == 0 &&
+           (_session->state_of_the_state() & Session::Deletion) == 0) {
+               // it's not a halt, but should be handled the same way:
+               // disable record, stop transport and I/O processign but save the data.
+               _session->engine_halted ();
+       }
+
+       if (stop_engine) {
+               _running = false;
        }
-       
-       _running = false;
        _processed_frames = 0;
-       _measuring_latency = false;
+       _measuring_latency = MeasureNone;
        _latency_output_port = 0;
        _latency_input_port = 0;
        _started_for_latency = false;
-       stop_metering_thread ();
-       
-       Port::PortDrop ();
 
-       if (!for_latency) {
+       if (stop_engine) {
+               Port::PortDrop ();
+       }
+
+       if (!for_latency && stop_engine) {
                Stopped (); /* EMIT SIGNAL */
        }
-       
+
        return 0;
 }
 
@@ -682,16 +956,16 @@ AudioEngine::freewheel (bool start_stop)
 }
 
 float
-AudioEngine::get_dsp_load() const 
+AudioEngine::get_dsp_load() const
 {
-       if (!_backend) {
+       if (!_backend || !_running) {
                return 0.0;
        }
        return _backend->dsp_load ();
 }
 
 bool
-AudioEngine::is_realtime() const 
+AudioEngine::is_realtime() const
 {
        if (!_backend) {
                return false;
@@ -701,7 +975,7 @@ AudioEngine::is_realtime() const
 }
 
 bool
-AudioEngine::connected() const 
+AudioEngine::connected() const
 {
        if (!_backend) {
                return false;
@@ -791,7 +1065,7 @@ AudioEngine::raw_buffer_size (DataType t)
        return _backend->raw_buffer_size (t);
 }
 
-pframes_t
+framepos_t
 AudioEngine::sample_time ()
 {
        if (!_backend) {
@@ -800,7 +1074,7 @@ AudioEngine::sample_time ()
        return _backend->sample_time ();
 }
 
-pframes_t
+framepos_t
 AudioEngine::sample_time_at_cycle_start ()
 {
        if (!_backend) {
@@ -878,6 +1152,7 @@ AudioEngine::set_sample_rate (float sr)
        if (!_backend) {
                return -1;
        }
+
        return _backend->set_sample_rate  (sr);
 }
 
@@ -890,15 +1165,6 @@ AudioEngine::set_buffer_size (uint32_t bufsiz)
        return _backend->set_buffer_size  (bufsiz);
 }
 
-int
-AudioEngine::set_sample_format (SampleFormat sf)
-{
-       if (!_backend) {
-               return -1;
-       }
-       return _backend->set_sample_format  (sf);
-}
-
 int
 AudioEngine::set_interleaved (bool yn)
 {
@@ -944,6 +1210,12 @@ AudioEngine::set_systemic_output_latency (uint32_t ol)
        return _backend->set_systemic_output_latency  (ol);
 }
 
+bool
+AudioEngine::thread_initialised_for_audio_processing ()
+{
+    return SessionEvent::has_per_thread_pool () && AsyncMIDIPort::is_process_thread();
+}
+
 /* END OF BACKEND PROXY API */
 
 void
@@ -955,14 +1227,15 @@ AudioEngine::thread_init_callback (void* arg)
 
        pthread_set_name (X_("audioengine"));
 
-       PBD::notify_gui_about_thread_creation ("gui", pthread_self(), X_("AudioEngine"), 4096);
-       PBD::notify_gui_about_thread_creation ("midiui", pthread_self(), X_("AudioEngine"), 128);
-
-       SessionEvent::create_per_thread_pool (X_("AudioEngine"), 512);
+       const int thread_num = g_atomic_int_add (&audioengine_thread_cnt, 1);
+       const string thread_name = string_compose (X_("AudioEngine %1"), thread_num);
 
+       SessionEvent::create_per_thread_pool (thread_name, 512);
+       PBD::notify_event_loops_about_thread_creation (pthread_self(), thread_name, 4096);
        AsyncMIDIPort::set_process_thread (pthread_self());
 
        if (arg) {
+               delete AudioEngine::instance()->_main_thread;
                /* the special thread created/managed by the backend */
                AudioEngine::instance()->_main_thread = new ProcessThread;
        }
@@ -1007,7 +1280,6 @@ AudioEngine::halted_callback (const char* why)
                return;
        }
 
-        stop_metering_thread ();
        _running = false;
 
        Port::PortDrop (); /* EMIT SIGNAL */
@@ -1020,49 +1292,52 @@ AudioEngine::halted_callback (const char* why)
 bool
 AudioEngine::setup_required () const
 {
-       /* If there is only a single backend and it claims to be configured
-        * already there is no setup to be done.
-        *
-        * Primarily for a case where there is only a JACK backend and
-        * JACK is already running.
-        */
-        
-       if (_backends.size() == 1 && _backends.begin()->second->already_configured()) {
-               return false;
+       if (_backend) {
+               if (_backend->info().already_configured())
+                       return false;
+       } else {
+               if (_backends.size() == 1 && _backends.begin()->second->already_configured()) {
+                       return false;
+               }
        }
 
        return true;
 }
 
-MTDM*
-AudioEngine::mtdm() 
-{
-       return _mtdm;
-}
-
 int
 AudioEngine::prepare_for_latency_measurement ()
 {
+       if (!_backend) {
+               return -1;
+       }
+
+       if (_backend->can_change_systemic_latency_when_running()) {
+               if (start()) {
+                       return -1;
+               }
+               _backend->set_systemic_input_latency (0);
+               _backend->set_systemic_output_latency (0);
+               return 0;
+       }
+
        if (running()) {
                _stopped_for_latency = true;
                stop (true);
        }
 
        if (start (true)) {
-               _started_for_latency = true;
                return -1;
        }
+       _started_for_latency = true;
 
        return 0;
 }
 
 int
-AudioEngine::start_latency_detection ()
+AudioEngine::start_latency_detection (bool for_midi)
 {
-       if (!running()) {
-               if (prepare_for_latency_measurement ()) {
-                       return -1;
-               }
+       if (prepare_for_latency_measurement ()) {
+               return -1;
        }
 
        PortEngine& pe (port_engine());
@@ -1070,6 +1345,9 @@ AudioEngine::start_latency_detection ()
        delete _mtdm;
        _mtdm = 0;
 
+       delete _mididm;
+       _mididm = 0;
+
        /* find the ports we will connect to */
 
        PortEngine::PortHandle out = pe.get_port_by_name (_latency_output_name);
@@ -1081,27 +1359,61 @@ AudioEngine::start_latency_detection ()
        }
 
        /* create the ports we will use to read/write data */
-       
-       if ((_latency_output_port = pe.register_port ("latency_out", DataType::AUDIO, IsOutput)) == 0) {
-               stop (true);
-               return -1;
-       }
-       if (pe.connect (_latency_output_port, _latency_output_name)) {
-               pe.unregister_port (_latency_output_port);
-               stop (true);
-               return -1;
-       }
+       if (for_midi) {
+               if ((_latency_output_port = pe.register_port ("latency_out", DataType::MIDI, IsOutput)) == 0) {
+                       stop (true);
+                       return -1;
+               }
+               if (pe.connect (_latency_output_port, _latency_output_name)) {
+                       pe.unregister_port (_latency_output_port);
+                       stop (true);
+                       return -1;
+               }
+
+               const string portname ("latency_in");
+               if ((_latency_input_port = pe.register_port (portname, DataType::MIDI, IsInput)) == 0) {
+                       pe.unregister_port (_latency_input_port);
+                       pe.unregister_port (_latency_output_port);
+                       stop (true);
+                       return -1;
+               }
+               if (pe.connect (_latency_input_name, make_port_name_non_relative (portname))) {
+                       pe.unregister_port (_latency_input_port);
+                       pe.unregister_port (_latency_output_port);
+                       stop (true);
+                       return -1;
+               }
+
+               _mididm = new MIDIDM (sample_rate());
+
+       } else {
+
+               if ((_latency_output_port = pe.register_port ("latency_out", DataType::AUDIO, IsOutput)) == 0) {
+                       stop (true);
+                       return -1;
+               }
+               if (pe.connect (_latency_output_port, _latency_output_name)) {
+                       pe.unregister_port (_latency_output_port);
+                       stop (true);
+                       return -1;
+               }
+
+               const string portname ("latency_in");
+               if ((_latency_input_port = pe.register_port (portname, DataType::AUDIO, IsInput)) == 0) {
+                       pe.unregister_port (_latency_input_port);
+                       pe.unregister_port (_latency_output_port);
+                       stop (true);
+                       return -1;
+               }
+               if (pe.connect (_latency_input_name, make_port_name_non_relative (portname))) {
+                       pe.unregister_port (_latency_input_port);
+                       pe.unregister_port (_latency_output_port);
+                       stop (true);
+                       return -1;
+               }
+
+               _mtdm = new MTDM (sample_rate());
 
-       const string portname ("latency_in");
-       if ((_latency_input_port = pe.register_port (portname, DataType::AUDIO, IsInput)) == 0) {
-               pe.unregister_port (_latency_output_port);
-               stop (true);
-               return -1;
-       }
-       if (pe.connect (_latency_input_name, make_port_name_non_relative (portname))) {
-               pe.unregister_port (_latency_output_port);
-               stop (true);
-               return -1;
        }
 
        LatencyRange lr;
@@ -1112,10 +1424,8 @@ AudioEngine::start_latency_detection ()
        _latency_signal_latency += lr.max;
 
        /* all created and connected, lets go */
-
-       _mtdm = new MTDM (sample_rate());
-       _measuring_latency = true;
-        _latency_flush_frames = samples_per_cycle();
+       _latency_flush_frames = samples_per_cycle();
+       _measuring_latency = for_midi ? MeasureMIDI : MeasureAudio;
 
        return 0;
 }
@@ -1123,7 +1433,7 @@ AudioEngine::start_latency_detection ()
 void
 AudioEngine::stop_latency_detection ()
 {
-       _measuring_latency = false;
+       _measuring_latency = MeasureNone;
 
        if (_latency_output_port) {
                port_engine().unregister_port (_latency_output_port);
@@ -1134,7 +1444,9 @@ AudioEngine::stop_latency_detection ()
                _latency_input_port = 0;
        }
 
-       stop (true);
+       if (!_backend->can_change_systemic_latency_when_running()) {
+               stop (true);
+       }
 
        if (_stopped_for_latency) {
                start ();