jackclient.h

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/******************************************************************************
 Copyright (c) 2012-2016 Institut für Nachrichtentechnik, Universität Rostock
 Copyright (c) 2006-2012 Quality & Usability Lab
                         Deutsche Telekom Laboratories, TU Berlin
 
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// https://AudioProcessingFramework.github.io/
 
 
#ifndef APF_JACKCLIENT_H
#define APF_JACKCLIENT_H
 
#include <jack/jack.h>
#include <jack/thread.h>
#include <jack/types.h>
#include <string>
#include <vector>
#include <utility>    // for std::pair
#include <stdexcept>  // for std::runtime_error
#include <cassert>    // for assert()
#include <errno.h>    // for EEXIST
 
#ifdef APF_JACKCLIENT_DEBUG
#include <jack/statistics.h>  // for jack_get_xrun_delayed_usecs()
#define APF_JACKCLIENT_DEBUG_MSG(str) \
  do { std::cout << "apf::JackClient: " << str << std::endl; } while (false)
#else
#define APF_JACKCLIENT_DEBUG_MSG(str) do { } while (false)
#endif
 
namespace apf
{
 
class JackClient
{
  public:
    typedef jack_default_audio_sample_t sample_t;
    typedef jack_nframes_t              nframes_t;
    typedef jack_port_t                 port_t;
 
    enum callback_usage_t
    {
      dont_use_jack_process_callback = 0,
      use_jack_process_callback
    };
 
    struct jack_error : std::runtime_error
    {
      jack_error(const std::string& s)
        : std::runtime_error("JackClient: " + s)
      {}
 
      jack_error(jack_status_t s)
        : std::runtime_error(std::string("JackClient: ")
        + ((s & JackInvalidOption)
                ? "The operation contained an invalid or unsupported option!"
        : (s & JackShmFailure) ? "Unable to access shared memory!"
        : (s & JackVersionError) ? "Client's protocol version does not match!"
        : (s & JackClientZombie) ? "Zombie!"
        : (s & JackNoSuchClient) ? "Requested client does not exist!"
        : (s & JackLoadFailure) ? "Unable to load internal client!"
        : (s & JackInitFailure) ? "Unable to initialize client!"
        : (s & JackBackendError) ? "Backend error!"
        : (s & JackNameNotUnique & JackFailure)
                ? "The client name is not unique!"
        : (s & JackServerFailed) ? "Unable to connect to the JACK server!"
        : (s & JackServerError) ? "Communication error with the JACK server!"
        : (s & JackFailure) ? "Overall operation failed!"
        : "Unknown error!"))
      {}
    };
 
    explicit inline JackClient(const std::string& name = "JackClient"
        , callback_usage_t callback_usage = dont_use_jack_process_callback);
 
    virtual ~JackClient()
    {
      if (_client)
      {
        // this->deactivate() has to be called in the derived dtor or earlier!
        jack_client_close(_client);
        // return value is ignored, because we're shutting down anyway ...
      }
    }
 
    bool activate() const
    {
      APF_JACKCLIENT_DEBUG_MSG("Activating JACK client.");
      if (!_client || jack_activate(_client)) return false;
 
      this->connect_pending_connections();
 
      // TODO: Still pending connections are ignored!
 
      return true;
    }
 
    bool deactivate() const
    {
      APF_JACKCLIENT_DEBUG_MSG("pending connections @ deactivate(): "
          << _pending_connections.size());
      return _client ? !jack_deactivate(_client) : false;
    }
 
 
 
    port_t* register_in_port(const std::string& name) const
    {
      return this->register_port(name, JackPortIsInput);
    }
 
    port_t* register_out_port(const std::string& name) const
    {
      return this->register_port(name, JackPortIsOutput);
    }
 
    port_t* register_port(const std::string& name, unsigned long flags) const
    {
      return jack_port_register(_client, name.c_str(), JACK_DEFAULT_AUDIO_TYPE
          , flags, 0);
    }
 
    bool unregister_port(port_t* port) const
    {
      if (!jack_port_unregister(_client, port))
      {
        port = nullptr; // port still points somewhere. Set to NULL.
        return true;
      }
      else
      {
        return false;
      }
    }
 
    bool connect_ports(const std::string& source
        , const std::string& destination) const
    {
      return _connect_ports_helper(source, destination, _pending_connections);
    }
 
    bool disconnect_ports(const std::string& source
        , const std::string& destination) const
    {
      return !jack_disconnect(_client, source.c_str(), destination.c_str());
    }
 
    bool connect_pending_connections() const
    {
      _pending_connections_t still_pending_connections;
 
      APF_JACKCLIENT_DEBUG_MSG("Connecting " << _pending_connections.size()
          << " pending connections ...");
      while (_pending_connections.size() > 0)
      {
        _connect_ports_helper(_pending_connections.back().first
            , _pending_connections.back().second, still_pending_connections);
        _pending_connections.pop_back();
      }
      APF_JACKCLIENT_DEBUG_MSG("Still pending connections: "
          << still_pending_connections.size());
 
      _pending_connections.swap(still_pending_connections);
 
      return _pending_connections.empty();
    }
 
 
 
 
    void transport_start() const
    {
      if (_client) jack_transport_start(_client);
    }
 
    void transport_stop() const
    {
      if (_client) jack_transport_stop(_client);
    }
 
    bool transport_locate(nframes_t frame) const
    {
      return _client ? !jack_transport_locate(_client, frame) : false;
    }
 
    std::pair<bool, nframes_t> get_transport_state() const
    {
      std::pair<bool, nframes_t> result(false, 0);
 
      if (_client)
      {
        jack_position_t jp;
        jack_transport_state_t jts = jack_transport_query(_client, &jp);
        result.first  = (jts == JackTransportRolling);
        result.second =  jp.frame;
      }
      return result;
    }
 
 
    bool set_freewheel(int onoff) const
    {
      return _client ? !jack_set_freewheel(_client, onoff) : false;
    }
 
    std::string client_name() const { return _client_name; }
    nframes_t   sample_rate() const { return _sample_rate; }
    nframes_t   buffer_size() const { return _buffer_size; }
 
    bool is_realtime() const
    {
      return _client ? jack_is_realtime(_client) : false;
    }
 
    int get_real_time_priority() const
    {
      return _client ? jack_client_real_time_priority(_client) : -1;
    }
 
    float get_cpu_load() const
    {
      return _client ? jack_cpu_load(_client) : 100.0f;
    }
 
    jack_native_thread_t client_thread_id() const
    {
      return _client ? jack_client_thread_id(_client) : 0;
    }
 
#ifdef APF_DOXYGEN_HACK
  protected:
#else
  private:
#endif
 
 
 
    virtual int jack_process_callback(nframes_t nframes)
    {
      (void)nframes;  // avoid "unused parameter" warning
      throw jack_error("jack_process_callback() not implemented!");
    }
 
    virtual int jack_sync_callback(jack_transport_state_t state
        , jack_position_t *pos)
    {
      (void)state;
      (void)pos;
      return 1;
    }
 
    virtual void jack_shutdown_callback()
    {
      throw jack_error("JACK shutdown!");
    }
 
    virtual int jack_sample_rate_callback(nframes_t sr)
    {
      (void)sr;
      throw jack_error("Sample rate changes are not supported!");
    }
 
    virtual int jack_buffer_size_callback(nframes_t bs)
    {
      (void)bs;
      throw jack_error("Buffer size changes are not supported!");
    }
 
    virtual int jack_xrun_callback()
    {
      APF_JACKCLIENT_DEBUG_MSG("JACK server reports xrun of "
        << jack_get_xrun_delayed_usecs(_client)/1000.0f << " msecs.");
      return 0;
    }
 
 
  private:
    // Internal redirection functions for callbacks
    // Map void pointers to class instances and call member functions
 
    static int _jack_process_callback(nframes_t nframes, void* arg)
    {
      return static_cast<JackClient*>(arg)->jack_process_callback(nframes);
    }
 
    static int _jack_sync_callback(jack_transport_state_t state
        , jack_position_t *pos, void* arg)
    {
      return static_cast<JackClient*>(arg)->jack_sync_callback(state, pos);
    }
 
    static void _jack_shutdown_callback(void* arg)
    {
      static_cast<JackClient*>(arg)->jack_shutdown_callback();
    }
 
    static int _jack_sample_rate_callback(nframes_t sr, void* arg)
    {
      return static_cast<JackClient*>(arg)->jack_sample_rate_callback(sr);
    }
 
    static int _jack_buffer_size_callback(nframes_t bs, void* arg)
    {
      return static_cast<JackClient*>(arg)->jack_buffer_size_callback(bs);
    }
 
    static int _jack_xrun_callback(void* arg)
    {
      return static_cast<JackClient*>(arg)->jack_xrun_callback();
    }
 
    typedef std::vector<std::pair<std::string, std::string>>
      _pending_connections_t;
 
    bool _connect_ports_helper(const std::string& source
        , const std::string& destination
        , _pending_connections_t& pending_connections) const
    {
      APF_JACKCLIENT_DEBUG_MSG("Connection: " << source << " -> " << destination);
      if (_client == nullptr) return false;
      int success = jack_connect(_client, source.c_str(), destination.c_str());
      APF_JACKCLIENT_DEBUG_MSG("Connection returned: " << success);
 
      switch (success)
      {
        case 0:
          break;
        case EEXIST:
          APF_JACKCLIENT_DEBUG_MSG("Connection already exists! ("
              << source << " -> " << destination << ")");
          break;
        default:
          APF_JACKCLIENT_DEBUG_MSG("Unable to connect "
              << source << " -> " << destination
              << "! Adding this to pending connections ...");
          pending_connections.push_back(std::make_pair(source, destination));
          // TODO: return something else than true/false?
          return false;
      }
      return true;
    }
 
    std::string    _client_name;  // Name of JACK client
    jack_client_t* _client;       // Pointer to JACK client.
    nframes_t      _sample_rate;  // sample rate of JACK server
    nframes_t      _buffer_size;  // buffer size of JACK server
 
    mutable _pending_connections_t _pending_connections;
 
    JackClient(const JackClient&);             // deactivated
    JackClient& operator=(const JackClient&);  // deactivated
};
 
JackClient::JackClient(const std::string& name
    , callback_usage_t callback_usage)
  : _client_name(name)
  , _client(nullptr) // will be set after connecting to JACK
  , _sample_rate(0)  //             -- " --
  , _buffer_size(0)  //             -- " --
{
  // check if client name is too long
  // jack_client_name_size() returns the size including the terminating \0
  // character, hence the ">=".
  if (name.size()
      >= static_cast<std::string::size_type>(jack_client_name_size()))
  {
    throw jack_error("Client name is too long! ('" + name + "')");
  }
 
  jack_options_t options = static_cast<jack_options_t>(
      JackNoStartServer | JackUseExactName);
 
  jack_status_t status;
  _client = jack_client_open(name.c_str(), options, &status);
  if (!_client) throw jack_error(status);
 
  if (status & JackServerStarted) {
    APF_JACKCLIENT_DEBUG_MSG("Server started.");
  }
  if (status & JackNameNotUnique) {
    _client_name = jack_get_client_name(_client);
    APF_JACKCLIENT_DEBUG_MSG("Unique name assigned: " << _client_name);
  }
 
  if (options & JackUseExactName)
  {
    assert(_client_name == jack_get_client_name(_client));
  }
  else
  {
    _client_name = jack_get_client_name(_client);
  }
 
  // TODO: error callback
  //jack_set_error_function(default_jack_error_callback);
 
  if (callback_usage == use_jack_process_callback)
  {
    if (jack_set_process_callback(_client, _jack_process_callback, this))
    {
      throw jack_error("Could not set process callback function for '"
          + _client_name + "'!");
    }
 
    // TODO: separate option to disable sync callback?
    if (jack_set_sync_callback(_client, _jack_sync_callback, this))
    {
      throw jack_error("Could not set sync callback function for '"
          + _client_name + "'!");
    }
  }
  // jack_on_info_shutdown CAUSES ISSUES ON WINDOWS
  // Using jack_on_shutdown instead
  jack_on_shutdown(_client, _jack_shutdown_callback, this);
 
  if (jack_set_xrun_callback(_client, _jack_xrun_callback, this))
  {
    throw jack_error("Could not set xrun callback function for '"
        + _client_name + "'!");
  }
 
  // TODO: is the following still valid?
  // sometimes, jack_activate() returns successful although an error occured and
  // the thing "zombified". if the shutdown handler is called, _client is reset
  // to zero which we can check now:
  if (!_client)
  {
    throw jack_error("\"" + _client_name + "\" was killed somehow!");
  }
 
  _sample_rate = jack_get_sample_rate(_client);
  _buffer_size = jack_get_buffer_size(_client);
}
 
}  // namespace apf
 
#undef APF_JACKCLIENT_DEBUG_MSG
 
#endif