From 822c460d15f9dfe5edcfd5a3fad6f2a0d0835552 Mon Sep 17 00:00:00 2001 From: Robin Gareus Date: Thu, 5 Jun 2014 02:08:56 +0200 Subject: [PATCH] DBus ALSA device reservation --- libs/backends/alsa/alsa_audiobackend.cc | 89 +++++++++++++++++++------ libs/backends/alsa/alsa_audiobackend.h | 11 ++- 2 files changed, 77 insertions(+), 23 deletions(-) diff --git a/libs/backends/alsa/alsa_audiobackend.cc b/libs/backends/alsa/alsa_audiobackend.cc index e8198ba333..1e80022c95 100644 --- a/libs/backends/alsa/alsa_audiobackend.cc +++ b/libs/backends/alsa/alsa_audiobackend.cc @@ -29,8 +29,8 @@ #include "pbd/compose.h" #include "pbd/error.h" #include "pbd/file_utils.h" +#include "ardour/filesystem_paths.h" #include "ardour/port_manager.h" -#include "ardour/system_exec.h" #include "ardouralsautil/devicelist.h" #include "i18n.h" @@ -47,6 +47,7 @@ AlsaAudioBackend::AlsaAudioBackend (AudioEngine& e, AudioBackendInfo& info) , _freewheeling (false) , _audio_device("") , _midi_device("") + , _device_reservation(0) , _samplerate (48000) , _samples_per_period (1024) , _periods_per_cycle (2) @@ -92,7 +93,24 @@ AlsaAudioBackend::enumerate_devices () const return s; } -static void acquire_device(const char* device_name) +void +AlsaAudioBackend::reservation_stdout (std::string d, size_t /* s */) +{ + if (d.substr(0, 19) == "Acquired audio-card") { + _reservation_succeeded = true; + } +} + +void +AlsaAudioBackend::release_device() +{ + _reservation_connection.drop_connections(); + delete _device_reservation; + _device_reservation = 0; +} + +bool +AlsaAudioBackend::acquire_device(const char* device_name) { /* This is quick hack, ideally we'll link against libdbus and implement a dbus-listener * that owns the device. here we try to get away by just requesting it and then block it... @@ -102,32 +120,50 @@ static void acquire_device(const char* device_name) * -> should not return 'boolean false' */ int device_number = card_to_num(device_name); - if (device_number < 0) return; + if (device_number < 0) return false; - std::string dbus_send_path; - if (PBD::find_file_in_search_path (PBD::Searchpath(Glib::getenv("PATH")), X_("dbus-send"), dbus_send_path)) { + assert(_device_reservation == 0); + _reservation_succeeded = false; + + std::string request_device_exe; + if (!PBD::find_file_in_search_path ( + PBD::Searchpath(Glib::build_filename(ARDOUR::ardour_dll_directory(), "ardouralsautil") + + G_SEARCHPATH_SEPARATOR_S + ARDOUR::ardour_dll_directory()), + "ardour-request-device", request_device_exe)) + { + PBD::warning << "ardour-request-device binary was not found..'" << endmsg; + return false; + } + else + { char **argp; char tmp[128]; - argp=(char**) calloc(8,sizeof(char*)); - argp[0] = strdup(dbus_send_path.c_str()); - argp[1] = strdup("--session"); - argp[2] = strdup("--print-reply"); // need to wait for the receiver to act. - argp[3] = strdup("--type=method_call"); - snprintf(tmp, sizeof(tmp), "--dest=org.freedesktop.ReserveDevice1.Audio%d", device_number); - argp[4] = strdup(tmp); - snprintf(tmp, sizeof(tmp), "/org/freedesktop/ReserveDevice1/Audio%d", device_number); - argp[5] = strdup(tmp); - argp[6] = strdup("org.freedesktop.ReserveDevice1.RequestRelease"); - argp[7] = strdup("int32:4294967296"); - snprintf(tmp, sizeof(tmp), "string:'org.freedesktop.ReserveDevice1.Audio%d'", device_number); - argp[7] = strdup(tmp); - argp[8] = 0; + argp=(char**) calloc(3,sizeof(char*)); + argp[0] = strdup(request_device_exe.c_str()); + snprintf(tmp, sizeof(tmp), "Audio%d", device_number); + argp[1] = strdup(tmp); + argp[2] = 0; - ARDOUR::SystemExec process (dbus_send_path, argp); - if (!process.start(1)) { - process.wait(); + _device_reservation = new ARDOUR::SystemExec(request_device_exe, argp); + _device_reservation->ReadStdout.connect_same_thread (_reservation_connection, boost::bind (&AlsaAudioBackend::reservation_stdout, this, _1 ,_2)); + _device_reservation->Terminated.connect_same_thread (_reservation_connection, boost::bind (&AlsaAudioBackend::release_device, this)); + if (_device_reservation->start(0)) { + PBD::warning << _("AlsaAudioBackend: Device Request failed.") << endmsg; + release_device(); + return false; } } + // wait to check if reservation suceeded. + int timeout = 500; // 5 sec + while (_device_reservation && !_reservation_succeeded && --timeout > 0) { + Glib::usleep(10000); + } + if (timeout == 0 || !_reservation_succeeded) { + PBD::warning << _("AlsaAudioBackend: Device Reservation failed.") << endmsg; + release_device(); + return false; + } + return true; } std::vector @@ -355,6 +391,8 @@ AlsaAudioBackend::_start (bool for_latency_measurement) _ports.clear(); } + release_device(); + assert(_rmidi_in.size() == 0); assert(_rmidi_out.size() == 0); assert(_pcmi == 0); @@ -383,6 +421,7 @@ AlsaAudioBackend::_start (bool for_latency_measurement) } if (_pcmi->state ()) { delete _pcmi; _pcmi = 0; + release_device(); return -1; } @@ -429,12 +468,14 @@ AlsaAudioBackend::_start (bool for_latency_measurement) if (register_system_audio_ports()) { PBD::error << _("AlsaAudioBackend: failed to register system ports.") << endmsg; delete _pcmi; _pcmi = 0; + release_device(); return -1; } if (engine.reestablish_ports ()) { PBD::error << _("AlsaAudioBackend: Could not re-establish ports.") << endmsg; delete _pcmi; _pcmi = 0; + release_device(); return -1; } @@ -449,6 +490,7 @@ AlsaAudioBackend::_start (bool for_latency_measurement) { PBD::error << _("AlsaAudioBackend: failed to create process thread.") << endmsg; delete _pcmi; _pcmi = 0; + release_device(); _run = false; return -1; } else { @@ -462,6 +504,7 @@ AlsaAudioBackend::_start (bool for_latency_measurement) if (timeout == 0 || !_active) { PBD::error << _("AlsaAudioBackend: failed to start process thread.") << endmsg; delete _pcmi; _pcmi = 0; + release_device(); _run = false; return -1; } @@ -498,6 +541,8 @@ AlsaAudioBackend::stop () unregister_system_ports(); delete _pcmi; _pcmi = 0; + release_device(); + return (_active == false) ? 0 : -1; } diff --git a/libs/backends/alsa/alsa_audiobackend.h b/libs/backends/alsa/alsa_audiobackend.h index 6ad58161f3..386a83a33f 100644 --- a/libs/backends/alsa/alsa_audiobackend.h +++ b/libs/backends/alsa/alsa_audiobackend.h @@ -30,8 +30,9 @@ #include -#include "ardour/types.h" #include "ardour/audio_backend.h" +#include "ardour/system_exec.h" +#include "ardour/types.h" #include "zita-alsa-pcmi.h" #include "alsa_rawmidi.h" @@ -288,6 +289,14 @@ class AlsaAudioBackend : public AudioBackend { std::string _audio_device; std::string _midi_device; + /* audio device reservation */ + ARDOUR::SystemExec *_device_reservation; + PBD::ScopedConnectionList _reservation_connection; + void reservation_stdout (std::string, size_t); + bool acquire_device(const char* device_name); + void release_device(); + bool _reservation_succeeded; + float _samplerate; size_t _samples_per_period; size_t _periods_per_cycle;