1 // Copyright 2014 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #include "media/midi/midi_manager_alsa.h" 6 7 #include <alsa/asoundlib.h> 8 #include <stdlib.h> 9 #include <algorithm> 10 #include <string> 11 12 #include "base/bind.h" 13 #include "base/logging.h" 14 #include "base/memory/ref_counted.h" 15 #include "base/memory/scoped_vector.h" 16 #include "base/message_loop/message_loop.h" 17 #include "base/posix/eintr_wrapper.h" 18 #include "base/strings/stringprintf.h" 19 #include "base/threading/thread.h" 20 #include "base/time/time.h" 21 #include "media/midi/midi_port_info.h" 22 23 namespace media { 24 25 namespace { 26 27 // Per-output buffer. This can be smaller, but then large sysex messages 28 // will be (harmlessly) split across multiple seq events. This should 29 // not have any real practical effect, except perhaps to slightly reorder 30 // realtime messages with respect to sysex. 31 const size_t kSendBufferSize = 256; 32 33 // Constants for the capabilities we search for in inputs and outputs. 34 // See http://www.alsa-project.org/alsa-doc/alsa-lib/seq.html. 35 const unsigned int kRequiredInputPortCaps = 36 SND_SEQ_PORT_CAP_READ | SND_SEQ_PORT_CAP_SUBS_READ; 37 const unsigned int kRequiredOutputPortCaps = 38 SND_SEQ_PORT_CAP_WRITE | SND_SEQ_PORT_CAP_SUBS_WRITE; 39 40 int AddrToInt(const snd_seq_addr_t* addr) { 41 return (addr->client << 8) | addr->port; 42 } 43 44 class CardInfo { 45 public: 46 CardInfo(const std::string name, const std::string manufacturer, 47 const std::string driver) 48 : name_(name), manufacturer_(manufacturer), driver_(driver) { 49 } 50 const std::string name_; 51 const std::string manufacturer_; 52 const std::string driver_; 53 }; 54 55 } // namespace 56 57 MidiManagerAlsa::MidiManagerAlsa() 58 : in_client_(NULL), 59 out_client_(NULL), 60 out_client_id_(-1), 61 in_port_(-1), 62 decoder_(NULL), 63 send_thread_("MidiSendThread"), 64 event_thread_("MidiEventThread"), 65 event_thread_shutdown_(false) { 66 // Initialize decoder. 67 snd_midi_event_new(0, &decoder_); 68 snd_midi_event_no_status(decoder_, 1); 69 } 70 71 void MidiManagerAlsa::StartInitialization() { 72 // TODO(agoode): Move off I/O thread. See http://crbug.com/374341. 73 74 // Create client handles. 75 int err = snd_seq_open(&in_client_, "hw", SND_SEQ_OPEN_INPUT, 0); 76 if (err != 0) { 77 VLOG(1) << "snd_seq_open fails: " << snd_strerror(err); 78 return CompleteInitialization(MIDI_INITIALIZATION_ERROR); 79 } 80 int in_client_id = snd_seq_client_id(in_client_); 81 err = snd_seq_open(&out_client_, "hw", SND_SEQ_OPEN_OUTPUT, 0); 82 if (err != 0) { 83 VLOG(1) << "snd_seq_open fails: " << snd_strerror(err); 84 return CompleteInitialization(MIDI_INITIALIZATION_ERROR); 85 } 86 out_client_id_ = snd_seq_client_id(out_client_); 87 88 // Name the clients. 89 err = snd_seq_set_client_name(in_client_, "Chrome (input)"); 90 if (err != 0) { 91 VLOG(1) << "snd_seq_set_client_name fails: " << snd_strerror(err); 92 return CompleteInitialization(MIDI_INITIALIZATION_ERROR); 93 } 94 err = snd_seq_set_client_name(out_client_, "Chrome (output)"); 95 if (err != 0) { 96 VLOG(1) << "snd_seq_set_client_name fails: " << snd_strerror(err); 97 return CompleteInitialization(MIDI_INITIALIZATION_ERROR); 98 } 99 100 // Create input port. 101 in_port_ = snd_seq_create_simple_port(in_client_, NULL, 102 SND_SEQ_PORT_CAP_WRITE | 103 SND_SEQ_PORT_CAP_NO_EXPORT, 104 SND_SEQ_PORT_TYPE_MIDI_GENERIC | 105 SND_SEQ_PORT_TYPE_APPLICATION); 106 if (in_port_ < 0) { 107 VLOG(1) << "snd_seq_create_simple_port fails: " << snd_strerror(in_port_); 108 return CompleteInitialization(MIDI_INITIALIZATION_ERROR); 109 } 110 111 // Subscribe to the announce port. 112 snd_seq_port_subscribe_t* subs; 113 snd_seq_port_subscribe_alloca(&subs); 114 snd_seq_addr_t announce_sender; 115 snd_seq_addr_t announce_dest; 116 announce_sender.client = SND_SEQ_CLIENT_SYSTEM; 117 announce_sender.port = SND_SEQ_PORT_SYSTEM_ANNOUNCE; 118 announce_dest.client = in_client_id; 119 announce_dest.port = in_port_; 120 snd_seq_port_subscribe_set_sender(subs, &announce_sender); 121 snd_seq_port_subscribe_set_dest(subs, &announce_dest); 122 err = snd_seq_subscribe_port(in_client_, subs); 123 if (err != 0) { 124 VLOG(1) << "snd_seq_subscribe_port on the announce port fails: " 125 << snd_strerror(err); 126 return CompleteInitialization(MIDI_INITIALIZATION_ERROR); 127 } 128 129 // Use a heuristic to extract the list of manufacturers for the hardware MIDI 130 // devices. This won't work for all devices. It is also brittle until 131 // hotplug is implemented. (See http://crbug.com/279097.) 132 // TODO(agoode): Make manufacturer extraction simple and reliable. 133 // http://crbug.com/377250. 134 ScopedVector<CardInfo> cards; 135 snd_ctl_card_info_t* card; 136 snd_rawmidi_info_t* midi_out; 137 snd_rawmidi_info_t* midi_in; 138 snd_ctl_card_info_alloca(&card); 139 snd_rawmidi_info_alloca(&midi_out); 140 snd_rawmidi_info_alloca(&midi_in); 141 for (int index = -1; !snd_card_next(&index) && index >= 0; ) { 142 const std::string id = base::StringPrintf("hw:CARD=%i", index); 143 snd_ctl_t* handle; 144 int err = snd_ctl_open(&handle, id.c_str(), 0); 145 if (err != 0) { 146 VLOG(1) << "snd_ctl_open fails: " << snd_strerror(err); 147 continue; 148 } 149 err = snd_ctl_card_info(handle, card); 150 if (err != 0) { 151 VLOG(1) << "snd_ctl_card_info fails: " << snd_strerror(err); 152 snd_ctl_close(handle); 153 continue; 154 } 155 // Enumerate any rawmidi devices (not subdevices) and extract CardInfo. 156 for (int device = -1; 157 !snd_ctl_rawmidi_next_device(handle, &device) && device >= 0; ) { 158 bool output; 159 bool input; 160 snd_rawmidi_info_set_device(midi_out, device); 161 snd_rawmidi_info_set_subdevice(midi_out, 0); 162 snd_rawmidi_info_set_stream(midi_out, SND_RAWMIDI_STREAM_OUTPUT); 163 output = snd_ctl_rawmidi_info(handle, midi_out) == 0; 164 snd_rawmidi_info_set_device(midi_in, device); 165 snd_rawmidi_info_set_subdevice(midi_in, 0); 166 snd_rawmidi_info_set_stream(midi_in, SND_RAWMIDI_STREAM_INPUT); 167 input = snd_ctl_rawmidi_info(handle, midi_in) == 0; 168 if (!output && !input) 169 continue; 170 171 snd_rawmidi_info_t* midi = midi_out ? midi_out : midi_in; 172 const std::string name = snd_rawmidi_info_get_name(midi); 173 // We assume that card longname is in the format of 174 // "<manufacturer> <name> at <bus>". Otherwise, we give up to detect 175 // a manufacturer name here. 176 std::string manufacturer; 177 const std::string card_name = snd_ctl_card_info_get_longname(card); 178 size_t at_index = card_name.rfind(" at "); 179 if (std::string::npos != at_index) { 180 size_t name_index = card_name.rfind(name, at_index - 1); 181 if (std::string::npos != name_index) 182 manufacturer = card_name.substr(0, name_index - 1); 183 } 184 const std::string driver = snd_ctl_card_info_get_driver(card); 185 cards.push_back(new CardInfo(name, manufacturer, driver)); 186 } 187 } 188 189 // Enumerate all ports in all clients. 190 snd_seq_client_info_t* client_info; 191 snd_seq_client_info_alloca(&client_info); 192 snd_seq_port_info_t* port_info; 193 snd_seq_port_info_alloca(&port_info); 194 195 snd_seq_client_info_set_client(client_info, -1); 196 // Enumerate clients. 197 uint32 current_input = 0; 198 unsigned int current_card = 0; 199 while (!snd_seq_query_next_client(in_client_, client_info)) { 200 int client_id = snd_seq_client_info_get_client(client_info); 201 if ((client_id == in_client_id) || (client_id == out_client_id_)) { 202 // Skip our own clients. 203 continue; 204 } 205 const std::string client_name = snd_seq_client_info_get_name(client_info); 206 snd_seq_port_info_set_client(port_info, client_id); 207 snd_seq_port_info_set_port(port_info, -1); 208 209 std::string manufacturer; 210 std::string driver; 211 // In the current Alsa kernel implementation, hardware clients match the 212 // cards in the same order. 213 if ((snd_seq_client_info_get_type(client_info) == SND_SEQ_KERNEL_CLIENT) && 214 (current_card < cards.size())) { 215 const CardInfo* info = cards[current_card]; 216 if (info->name_ == client_name) { 217 manufacturer = info->manufacturer_; 218 driver = info->driver_; 219 current_card++; 220 } 221 } 222 // Enumerate ports. 223 while (!snd_seq_query_next_port(in_client_, port_info)) { 224 unsigned int port_type = snd_seq_port_info_get_type(port_info); 225 if (port_type & SND_SEQ_PORT_TYPE_MIDI_GENERIC) { 226 const snd_seq_addr_t* addr = snd_seq_port_info_get_addr(port_info); 227 const std::string name = snd_seq_port_info_get_name(port_info); 228 const std::string id = base::StringPrintf("%d:%d %s", 229 addr->client, 230 addr->port, 231 name.c_str()); 232 std::string version; 233 if (driver != "") { 234 version = driver + " / "; 235 } 236 version += base::StringPrintf("ALSA library version %d.%d.%d", 237 SND_LIB_MAJOR, 238 SND_LIB_MINOR, 239 SND_LIB_SUBMINOR); 240 unsigned int caps = snd_seq_port_info_get_capability(port_info); 241 if ((caps & kRequiredInputPortCaps) == kRequiredInputPortCaps) { 242 // Subscribe to this port. 243 const snd_seq_addr_t* sender = snd_seq_port_info_get_addr(port_info); 244 snd_seq_addr_t dest; 245 dest.client = snd_seq_client_id(in_client_); 246 dest.port = in_port_; 247 snd_seq_port_subscribe_set_sender(subs, sender); 248 snd_seq_port_subscribe_set_dest(subs, &dest); 249 err = snd_seq_subscribe_port(in_client_, subs); 250 if (err != 0) { 251 VLOG(1) << "snd_seq_subscribe_port fails: " << snd_strerror(err); 252 } else { 253 source_map_[AddrToInt(sender)] = current_input++; 254 AddInputPort(MidiPortInfo(id, manufacturer, name, version)); 255 } 256 } 257 if ((caps & kRequiredOutputPortCaps) == kRequiredOutputPortCaps) { 258 // Create a port for us to send on. 259 int out_port = 260 snd_seq_create_simple_port(out_client_, NULL, 261 SND_SEQ_PORT_CAP_READ | 262 SND_SEQ_PORT_CAP_NO_EXPORT, 263 SND_SEQ_PORT_TYPE_MIDI_GENERIC | 264 SND_SEQ_PORT_TYPE_APPLICATION); 265 if (out_port < 0) { 266 VLOG(1) << "snd_seq_create_simple_port fails: " 267 << snd_strerror(out_port); 268 // Skip this output port for now. 269 continue; 270 } 271 272 // Activate port subscription. 273 snd_seq_addr_t sender; 274 const snd_seq_addr_t* dest = snd_seq_port_info_get_addr(port_info); 275 sender.client = snd_seq_client_id(out_client_); 276 sender.port = out_port; 277 snd_seq_port_subscribe_set_sender(subs, &sender); 278 snd_seq_port_subscribe_set_dest(subs, dest); 279 err = snd_seq_subscribe_port(out_client_, subs); 280 if (err != 0) { 281 VLOG(1) << "snd_seq_subscribe_port fails: " << snd_strerror(err); 282 snd_seq_delete_simple_port(out_client_, out_port); 283 } else { 284 snd_midi_event_t* encoder; 285 snd_midi_event_new(kSendBufferSize, &encoder); 286 encoders_.push_back(encoder); 287 out_ports_.push_back(out_port); 288 AddOutputPort(MidiPortInfo(id, manufacturer, name, version)); 289 } 290 } 291 } 292 } 293 } 294 295 event_thread_.Start(); 296 event_thread_.message_loop()->PostTask( 297 FROM_HERE, 298 base::Bind(&MidiManagerAlsa::EventReset, base::Unretained(this))); 299 300 CompleteInitialization(MIDI_OK); 301 } 302 303 MidiManagerAlsa::~MidiManagerAlsa() { 304 // Tell the event thread it will soon be time to shut down. This gives 305 // us assurance the thread will stop in case the SND_SEQ_EVENT_CLIENT_EXIT 306 // message is lost. 307 { 308 base::AutoLock lock(shutdown_lock_); 309 event_thread_shutdown_ = true; 310 } 311 312 // Stop the send thread. 313 send_thread_.Stop(); 314 315 // Close the out client. This will trigger the event thread to stop, 316 // because of SND_SEQ_EVENT_CLIENT_EXIT. 317 if (out_client_) 318 snd_seq_close(out_client_); 319 320 // Wait for the event thread to stop. 321 event_thread_.Stop(); 322 323 // Close the in client. 324 if (in_client_) 325 snd_seq_close(in_client_); 326 327 // Free the decoder. 328 snd_midi_event_free(decoder_); 329 330 // Free the encoders. 331 for (EncoderList::iterator i = encoders_.begin(); i != encoders_.end(); ++i) 332 snd_midi_event_free(*i); 333 } 334 335 void MidiManagerAlsa::SendMidiData(uint32 port_index, 336 const std::vector<uint8>& data) { 337 DCHECK(send_thread_.message_loop_proxy()->BelongsToCurrentThread()); 338 339 snd_midi_event_t* encoder = encoders_[port_index]; 340 for (unsigned int i = 0; i < data.size(); i++) { 341 snd_seq_event_t event; 342 int result = snd_midi_event_encode_byte(encoder, data[i], &event); 343 if (result == 1) { 344 // Full event, send it. 345 snd_seq_ev_set_source(&event, out_ports_[port_index]); 346 snd_seq_ev_set_subs(&event); 347 snd_seq_ev_set_direct(&event); 348 snd_seq_event_output_direct(out_client_, &event); 349 } 350 } 351 } 352 353 void MidiManagerAlsa::DispatchSendMidiData(MidiManagerClient* client, 354 uint32 port_index, 355 const std::vector<uint8>& data, 356 double timestamp) { 357 if (out_ports_.size() <= port_index) 358 return; 359 360 // Not correct right now. http://crbug.com/374341. 361 if (!send_thread_.IsRunning()) 362 send_thread_.Start(); 363 364 base::TimeDelta delay; 365 if (timestamp != 0.0) { 366 base::TimeTicks time_to_send = 367 base::TimeTicks() + base::TimeDelta::FromMicroseconds( 368 timestamp * base::Time::kMicrosecondsPerSecond); 369 delay = std::max(time_to_send - base::TimeTicks::Now(), base::TimeDelta()); 370 } 371 372 send_thread_.message_loop()->PostDelayedTask( 373 FROM_HERE, 374 base::Bind(&MidiManagerAlsa::SendMidiData, base::Unretained(this), 375 port_index, data), delay); 376 377 // Acknowledge send. 378 send_thread_.message_loop()->PostTask( 379 FROM_HERE, 380 base::Bind(&MidiManagerClient::AccumulateMidiBytesSent, 381 base::Unretained(client), data.size())); 382 } 383 384 void MidiManagerAlsa::EventReset() { 385 event_thread_.message_loop()->PostTask( 386 FROM_HERE, 387 base::Bind(&MidiManagerAlsa::EventLoop, base::Unretained(this))); 388 } 389 390 void MidiManagerAlsa::EventLoop() { 391 // Read available incoming MIDI data. 392 snd_seq_event_t* event; 393 int err = snd_seq_event_input(in_client_, &event); 394 double timestamp = 395 (base::TimeTicks::HighResNow() - base::TimeTicks()).InSecondsF(); 396 if (err == -ENOSPC) { 397 VLOG(1) << "snd_seq_event_input detected buffer overrun"; 398 399 // We've lost events: check another way to see if we need to shut down. 400 base::AutoLock lock(shutdown_lock_); 401 if (event_thread_shutdown_) { 402 return; 403 } 404 } else if (err < 0) { 405 VLOG(1) << "snd_seq_event_input fails: " << snd_strerror(err); 406 return; 407 } else { 408 // Check for disconnection of out client. This means "shut down". 409 if (event->source.client == SND_SEQ_CLIENT_SYSTEM && 410 event->source.port == SND_SEQ_PORT_SYSTEM_ANNOUNCE && 411 event->type == SND_SEQ_EVENT_CLIENT_EXIT && 412 event->data.addr.client == out_client_id_) { 413 return; 414 } 415 416 std::map<int, uint32>::iterator source_it = 417 source_map_.find(AddrToInt(&event->source)); 418 if (source_it != source_map_.end()) { 419 uint32 source = source_it->second; 420 if (event->type == SND_SEQ_EVENT_SYSEX) { 421 // Special! Variable-length sysex. 422 ReceiveMidiData(source, static_cast<const uint8*>(event->data.ext.ptr), 423 event->data.ext.len, 424 timestamp); 425 } else { 426 // Otherwise, decode this and send that on. 427 unsigned char buf[12]; 428 long count = snd_midi_event_decode(decoder_, buf, sizeof(buf), event); 429 if (count <= 0) { 430 if (count != -ENOENT) { 431 // ENOENT means that it's not a MIDI message, which is not an 432 // error, but other negative values are errors for us. 433 VLOG(1) << "snd_midi_event_decoder fails " << snd_strerror(count); 434 } 435 } else { 436 ReceiveMidiData(source, buf, count, timestamp); 437 } 438 } 439 } 440 } 441 442 // Do again. 443 event_thread_.message_loop()->PostTask( 444 FROM_HERE, 445 base::Bind(&MidiManagerAlsa::EventLoop, base::Unretained(this))); 446 } 447 448 MidiManager* MidiManager::Create() { 449 return new MidiManagerAlsa(); 450 } 451 452 } // namespace media 453
