git.sesse.net Git - nageru/blob - alsa_pool.cpp

   1 #include "alsa_pool.h"
   2
   3 #include <alsa/control.h>
   4 #include <alsa/error.h>
   5 #include <alsa/pcm.h>
   6 #include <assert.h>
   7 #include <limits.h>
   8 #include <stdio.h>
   9 #include <sys/inotify.h>
  10 #include <unistd.h>
  11 #include <algorithm>
  12 #include <memory>
  13
  14 #include "alsa_input.h"
  15 #include "audio_mixer.h"
  16 #include "defs.h"
  17 #include "input_mapping.h"
  18 #include "state.pb.h"
  19
  20 using namespace std;
  21 using namespace std::placeholders;
  22
  23 ALSAPool::~ALSAPool()
  24 {
  25         for (Device &device : devices) {
  26                 if (device.input != nullptr) {
  27                         device.input->stop_capture_thread();
  28                 }
  29         }
  30         should_quit = true;
  31         inotify_thread.join();
  32
  33         while (retry_threads_running > 0) {
  34                 this_thread::sleep_for(std::chrono::milliseconds(100));
  35         }
  36 }
  37
  38 std::vector<ALSAPool::Device> ALSAPool::get_devices()
  39 {
  40         lock_guard<mutex> lock(mu);
  41         for (Device &device : devices) {
  42                 device.held = true;
  43         }
  44         return devices;
  45 }
  46
  47 void ALSAPool::hold_device(unsigned index)
  48 {
  49         lock_guard<mutex> lock(mu);
  50         assert(index < devices.size());
  51         devices[index].held = true;
  52 }
  53
  54 void ALSAPool::release_device(unsigned index)
  55 {
  56         lock_guard<mutex> lock(mu);
  57         if (index < devices.size()) {
  58                 devices[index].held = false;
  59         }
  60 }
  61
  62 void ALSAPool::enumerate_devices()
  63 {
  64         // Enumerate all cards.
  65         for (int card_index = -1; snd_card_next(&card_index) == 0 && card_index >= 0; ) {
  66                 char address[256];
  67                 snprintf(address, sizeof(address), "hw:%d", card_index);
  68
  69                 snd_ctl_t *ctl;
  70                 int err = snd_ctl_open(&ctl, address, 0);
  71                 if (err < 0) {
  72                         printf("%s: %s\n", address, snd_strerror(err));
  73                         continue;
  74                 }
  75                 unique_ptr<snd_ctl_t, decltype(snd_ctl_close)*> ctl_closer(ctl, snd_ctl_close);
  76
  77                 // Enumerate all devices on this card.
  78                 for (int dev_index = -1; snd_ctl_pcm_next_device(ctl, &dev_index) == 0 && dev_index >= 0; ) {
  79                         probe_device_with_retry(card_index, dev_index);
  80                 }
  81         }
  82 }
  83
  84 void ALSAPool::probe_device_with_retry(unsigned card_index, unsigned dev_index)
  85 {
  86         char address[256];
  87         snprintf(address, sizeof(address), "hw:%d,%d", card_index, dev_index);
  88
  89         lock_guard<mutex> lock(add_device_mutex);
  90         if (add_device_tries_left.count(address)) {
  91                 // Some thread is already busy retrying this,
  92                 // so just reset its count.
  93                 add_device_tries_left[address] = num_retries;
  94                 return;
  95         }
  96
  97         // Try (while still holding the lock) to add the device synchronously.
  98         ProbeResult result = probe_device_once(card_index, dev_index);
  99         if (result == ProbeResult::SUCCESS) {
 100                 return;
 101         } else if (result == ProbeResult::FAILURE) {
 102                 return;
 103         }
 104         assert(result == ProbeResult::DEFER);
 105
 106         // Add failed for whatever reason (probably just that the device
 107         // isn't up yet. Set up a count so that nobody else starts a thread,
 108         // then start it ourselves.
 109         fprintf(stderr, "Trying %s again in one second...\n", address);
 110         add_device_tries_left[address] = num_retries;
 111         ++retry_threads_running;
 112         thread(&ALSAPool::probe_device_retry_thread_func, this, card_index, dev_index).detach();
 113 }
 114
 115 void ALSAPool::probe_device_retry_thread_func(unsigned card_index, unsigned dev_index)
 116 {
 117         char address[256];
 118         snprintf(address, sizeof(address), "hw:%d,%d", card_index, dev_index);
 119
 120         for ( ;; ) {  // Termination condition within the loop.
 121                 sleep(1);
 122
 123                 // See if there are any retries left.
 124                 lock_guard<mutex> lock(add_device_mutex);
 125                 if (should_quit ||
 126                     !add_device_tries_left.count(address) ||
 127                     add_device_tries_left[address] == 0) {
 128                         add_device_tries_left.erase(address);
 129                         fprintf(stderr, "Giving up probe of %s.\n", address);
 130                         break;
 131                 }
 132
 133                 // Seemingly there were. Give it a try (we still hold the mutex).
 134                 ProbeResult result = probe_device_once(card_index, dev_index);
 135                 if (result == ProbeResult::SUCCESS) {
 136                         add_device_tries_left.erase(address);
 137                         fprintf(stderr, "Probe of %s succeeded.\n", address);
 138                         break;
 139                 } else if (result == ProbeResult::FAILURE || --add_device_tries_left[address] == 0) {
 140                         add_device_tries_left.erase(address);
 141                         fprintf(stderr, "Giving up probe of %s.\n", address);
 142                         break;
 143                 }
 144
 145                 // Failed again.
 146                 assert(result == ProbeResult::DEFER);
 147                 fprintf(stderr, "Trying %s again in one second (%d tries left)...\n",
 148                         address, add_device_tries_left[address]);
 149         }
 150
 151         --retry_threads_running;
 152 }
 153
 154 ALSAPool::ProbeResult ALSAPool::probe_device_once(unsigned card_index, unsigned dev_index)
 155 {
 156         char address[256];
 157         snprintf(address, sizeof(address), "hw:%d", card_index);
 158         snd_ctl_t *ctl;
 159         int err = snd_ctl_open(&ctl, address, 0);
 160         if (err < 0) {
 161                 printf("%s: %s\n", address, snd_strerror(err));
 162                 return ALSAPool::ProbeResult::DEFER;
 163         }
 164         unique_ptr<snd_ctl_t, decltype(snd_ctl_close)*> ctl_closer(ctl, snd_ctl_close);
 165
 166         snd_pcm_info_t *pcm_info;
 167         snd_pcm_info_alloca(&pcm_info);
 168         snd_pcm_info_set_device(pcm_info, dev_index);
 169         snd_pcm_info_set_subdevice(pcm_info, 0);
 170         snd_pcm_info_set_stream(pcm_info, SND_PCM_STREAM_CAPTURE);
 171         if (snd_ctl_pcm_info(ctl, pcm_info) < 0) {
 172                 // Not available for capture.
 173                 printf("%s: Not available for capture.\n", address);
 174                 return ALSAPool::ProbeResult::DEFER;
 175         }
 176
 177         snprintf(address, sizeof(address), "hw:%d,%d", card_index, dev_index);
 178
 179         unsigned num_channels = 0;
 180
 181         // Find all channel maps for this device, and pick out the one
 182         // with the most channels.
 183         snd_pcm_chmap_query_t **cmaps = snd_pcm_query_chmaps_from_hw(card_index, dev_index, 0, SND_PCM_STREAM_CAPTURE);
 184         if (cmaps != nullptr) {
 185                 for (snd_pcm_chmap_query_t **ptr = cmaps; *ptr; ++ptr) {
 186                         num_channels = max(num_channels, (*ptr)->map.channels);
 187                 }
 188                 snd_pcm_free_chmaps(cmaps);
 189         }
 190         if (num_channels == 0) {
 191                 // Device had no channel maps. We need to open it to query.
 192                 // TODO: Do this asynchronously.
 193                 snd_pcm_t *pcm_handle;
 194                 int err = snd_pcm_open(&pcm_handle, address, SND_PCM_STREAM_CAPTURE, 0);
 195                 if (err < 0) {
 196                         printf("%s: %s\n", address, snd_strerror(err));
 197                         return ALSAPool::ProbeResult::DEFER;
 198                 }
 199                 snd_pcm_hw_params_t *hw_params;
 200                 snd_pcm_hw_params_alloca(&hw_params);
 201                 unsigned sample_rate;
 202                 if (!ALSAInput::set_base_params(address, pcm_handle, hw_params, &sample_rate)) {
 203                         snd_pcm_close(pcm_handle);
 204                         return ALSAPool::ProbeResult::DEFER;
 205                 }
 206                 err = snd_pcm_hw_params_get_channels_max(hw_params, &num_channels);
 207                 if (err < 0) {
 208                         fprintf(stderr, "[%s] snd_pcm_hw_params_get_channels_max(): %s\n",
 209                                 address, snd_strerror(err));
 210                         snd_pcm_close(pcm_handle);
 211                         return ALSAPool::ProbeResult::DEFER;
 212                 }
 213                 snd_pcm_close(pcm_handle);
 214         }
 215
 216         if (num_channels == 0) {
 217                 printf("%s: No channel maps with channels\n", address);
 218                 return ALSAPool::ProbeResult::FAILURE;
 219         }
 220
 221         snd_ctl_card_info_t *card_info;
 222         snd_ctl_card_info_alloca(&card_info);
 223         snd_ctl_card_info(ctl, card_info);
 224
 225         string name = snd_ctl_card_info_get_name(card_info);
 226         string info = snd_pcm_info_get_name(pcm_info);
 227
 228         unsigned internal_dev_index;
 229         string display_name;
 230         {
 231                 lock_guard<mutex> lock(mu);
 232                 internal_dev_index = find_free_device_index(name, info, num_channels, address);
 233                 devices[internal_dev_index].address = address;
 234                 devices[internal_dev_index].name = name;
 235                 devices[internal_dev_index].info = info;
 236                 devices[internal_dev_index].num_channels = num_channels;
 237                 // Note: Purposefully does not overwrite held.
 238
 239                 display_name = devices[internal_dev_index].display_name();
 240         }
 241
 242         fprintf(stderr, "%s: Probed successfully.\n", address);
 243
 244         reset_device(internal_dev_index);  // Restarts it if it is held (ie., we just replaced a dead card).
 245
 246         DeviceSpec spec{InputSourceType::ALSA_INPUT, internal_dev_index};
 247         global_audio_mixer->set_display_name(spec, display_name);
 248         global_audio_mixer->trigger_state_changed_callback();
 249
 250         return ALSAPool::ProbeResult::SUCCESS;
 251 }
 252
 253 void ALSAPool::unplug_device(unsigned card_index, unsigned dev_index)
 254 {
 255         char address[256];
 256         snprintf(address, sizeof(address), "hw:%d,%d", card_index, dev_index);
 257         for (unsigned i = 0; i < devices.size(); ++i) {
 258                 if (devices[i].state != Device::State::EMPTY &&
 259                     devices[i].state != Device::State::DEAD &&
 260                     devices[i].address == address) {
 261                         free_card(i);
 262                 }
 263         }
 264 }
 265
 266 void ALSAPool::init()
 267 {
 268         inotify_thread = thread(&ALSAPool::inotify_thread_func, this);
 269         enumerate_devices();
 270 }
 271
 272 void ALSAPool::inotify_thread_func()
 273 {
 274         int inotify_fd = inotify_init();
 275         if (inotify_fd == -1) {
 276                 perror("inotify_init()");
 277                 fprintf(stderr, "No hotplug of ALSA devices available.\n");
 278                 return;
 279         }
 280
 281         int watch_fd = inotify_add_watch(inotify_fd, "/dev/snd", IN_MOVE | IN_CREATE | IN_DELETE);
 282         if (watch_fd == -1) {
 283                 perror("inotify_add_watch()");
 284                 fprintf(stderr, "No hotplug of ALSA devices available.\n");
 285                 close(inotify_fd);
 286                 return;
 287         }
 288
 289         int size = sizeof(inotify_event) + NAME_MAX + 1;
 290         unique_ptr<char[]> buf(new char[size]);
 291         while (!should_quit) {
 292                 pollfd fds;
 293                 fds.fd = inotify_fd;
 294                 fds.events = POLLIN;
 295                 fds.revents = 0;
 296
 297                 int ret = poll(&fds, 1, 100);
 298                 if (ret == -1) {
 299                         if (errno == EINTR) {
 300                                 continue;
 301                         } else {
 302                                 perror("poll(inotify_fd)");
 303                                 return;
 304                         }
 305                 }
 306                 if (ret == 0) {
 307                         continue;
 308                 }
 309
 310                 ret = read(inotify_fd, buf.get(), size);
 311                 if (ret == -1) {
 312                         if (errno == EINTR) {
 313                                 continue;
 314                         } else {
 315                                 perror("read(inotify_fd)");
 316                                 close(watch_fd);
 317                                 close(inotify_fd);
 318                                 return;
 319                         }
 320                 }
 321                 if (ret < int(sizeof(inotify_event))) {
 322                         fprintf(stderr, "inotify read unexpectedly returned %d, giving up hotplug of ALSA devices.\n",
 323                                 int(ret));
 324                         close(watch_fd);
 325                         close(inotify_fd);
 326                         return;
 327                 }
 328
 329                 for (int i = 0; i < ret; ) {
 330                         const inotify_event *event = reinterpret_cast<const inotify_event *>(&buf[i]);
 331                         i += sizeof(inotify_event) + event->len;
 332
 333                         if (event->mask & IN_Q_OVERFLOW) {
 334                                 fprintf(stderr, "WARNING: inotify overflowed, may lose ALSA hotplug events.\n");
 335                                 continue;
 336                         }
 337                         unsigned card, device;
 338                         char type;
 339                         if (sscanf(event->name, "pcmC%uD%u%c", &card, &device, &type) == 3 && type == 'c') {
 340                                 if (event->mask & (IN_MOVED_FROM | IN_DELETE)) {
 341                                         printf("Deleted capture device: Card %u, device %u\n", card, device);
 342                                         unplug_device(card, device);
 343                                 }
 344                                 if (event->mask & (IN_MOVED_TO | IN_CREATE)) {
 345                                         printf("Adding capture device: Card %u, device %u\n", card, device);
 346                                         probe_device_with_retry(card, device);
 347                                 }
 348                         }
 349                 }
 350         }
 351         close(watch_fd);
 352         close(inotify_fd);
 353 }
 354
 355 void ALSAPool::reset_device(unsigned index)
 356 {
 357         lock_guard<mutex> lock(mu);
 358         Device *device = &devices[index];
 359         if (inputs[index] != nullptr) {
 360                 inputs[index]->stop_capture_thread();
 361         }
 362         if (!device->held) {
 363                 inputs[index].reset();
 364         } else {
 365                 // TODO: Put on a background thread instead of locking?
 366                 auto callback = bind(&AudioMixer::add_audio, global_audio_mixer, DeviceSpec{InputSourceType::ALSA_INPUT, index}, _1, _2, _3, _4);
 367                 inputs[index].reset(new ALSAInput(device->address.c_str(), OUTPUT_FREQUENCY, device->num_channels, callback, this, index));
 368                 inputs[index]->start_capture_thread();
 369         }
 370         device->input = inputs[index].get();
 371 }
 372
 373 unsigned ALSAPool::get_capture_frequency(unsigned index)
 374 {
 375         lock_guard<mutex> lock(mu);
 376         assert(devices[index].held);
 377         if (devices[index].input)
 378                 return devices[index].input->get_sample_rate();
 379         else
 380                 return OUTPUT_FREQUENCY;
 381 }
 382
 383 ALSAPool::Device::State ALSAPool::get_card_state(unsigned index)
 384 {
 385         lock_guard<mutex> lock(mu);
 386         assert(devices[index].held);
 387         return devices[index].state;
 388 }
 389
 390 void ALSAPool::set_card_state(unsigned index, ALSAPool::Device::State state)
 391 {
 392         {
 393                 lock_guard<mutex> lock(mu);
 394                 devices[index].state = state;
 395         }
 396
 397         DeviceSpec spec{InputSourceType::ALSA_INPUT, index};
 398         bool silence = (state != ALSAPool::Device::State::RUNNING);
 399         while (!global_audio_mixer->silence_card(spec, silence))
 400                 ;
 401         global_audio_mixer->trigger_state_changed_callback();
 402 }
 403
 404 unsigned ALSAPool::find_free_device_index(const string &name, const string &info, unsigned num_channels, const string &address)
 405 {
 406         // First try to find an exact match on a dead card.
 407         for (unsigned i = 0; i < devices.size(); ++i) {
 408                 if (devices[i].state == Device::State::DEAD &&
 409                     devices[i].address == address &&
 410                     devices[i].name == name &&
 411                     devices[i].info == info &&
 412                     devices[i].num_channels == num_channels) {
 413                         devices[i].state = Device::State::READY;
 414                         return i;
 415                 }
 416         }
 417
 418         // Then try to find a match on everything but the address
 419         // (probably that devices were plugged back in a different order).
 420         // If we have two cards that are equal, this might get them mixed up,
 421         // but we don't have anything better.
 422         for (unsigned i = 0; i < devices.size(); ++i) {
 423                 if (devices[i].state == Device::State::DEAD &&
 424                     devices[i].name == name &&
 425                     devices[i].info == info &&
 426                     devices[i].num_channels == num_channels) {
 427                         devices[i].state = Device::State::READY;
 428                         return i;
 429                 }
 430         }
 431
 432         // OK, so we didn't find a match; see if there are any empty slots.
 433         for (unsigned i = 0; i < devices.size(); ++i) {
 434                 if (devices[i].state == Device::State::EMPTY) {
 435                         devices[i].state = Device::State::READY;
 436                         devices[i].held = false;
 437                         return i;
 438                 }
 439         }
 440
 441         // Failing that, we just insert the new device at the end.
 442         Device new_dev;
 443         new_dev.state = Device::State::READY;
 444         new_dev.held = false;
 445         devices.push_back(new_dev);
 446         inputs.emplace_back(nullptr);
 447         return devices.size() - 1;
 448 }
 449
 450 unsigned ALSAPool::create_dead_card(const string &name, const string &info, unsigned num_channels)
 451 {
 452         lock_guard<mutex> lock(mu);
 453
 454         // See if there are any empty slots. If not, insert one at the end.
 455         vector<Device>::iterator free_device =
 456                 find_if(devices.begin(), devices.end(),
 457                         [](const Device &device) { return device.state == Device::State::EMPTY; });
 458         if (free_device == devices.end()) {
 459                 devices.push_back(Device());
 460                 inputs.emplace_back(nullptr);
 461                 free_device = devices.end() - 1;
 462         }
 463
 464         free_device->state = Device::State::DEAD;
 465         free_device->name = name;
 466         free_device->info = info;
 467         free_device->num_channels = num_channels;
 468         free_device->held = true;
 469
 470         return distance(devices.begin(), free_device);
 471 }
 472
 473 void ALSAPool::serialize_device(unsigned index, DeviceSpecProto *serialized)
 474 {
 475         lock_guard<mutex> lock(mu);
 476         assert(index < devices.size());
 477         assert(devices[index].held);
 478         serialized->set_type(DeviceSpecProto::ALSA_INPUT);
 479         serialized->set_index(index);
 480         serialized->set_display_name(devices[index].display_name());
 481         serialized->set_alsa_name(devices[index].name);
 482         serialized->set_alsa_info(devices[index].info);
 483         serialized->set_num_channels(devices[index].num_channels);
 484         serialized->set_address(devices[index].address);
 485 }
 486
 487 void ALSAPool::free_card(unsigned index)
 488 {
 489         DeviceSpec spec{InputSourceType::ALSA_INPUT, index};
 490         while (!global_audio_mixer->silence_card(spec, true))
 491                 ;
 492
 493         {
 494                 lock_guard<mutex> lock(mu);
 495                 if (devices[index].held) {
 496                         devices[index].state = Device::State::DEAD;
 497                 } else {
 498                         devices[index].state = Device::State::EMPTY;
 499                         inputs[index].reset();
 500                 }
 501                 while (!devices.empty() && devices.back().state == Device::State::EMPTY) {
 502                         devices.pop_back();
 503                         inputs.pop_back();
 504                 }
 505         }
 506
 507         global_audio_mixer->trigger_state_changed_callback();
 508 }