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

   1 #include "alsa_pool.h"
   2
   3 #include <alsa/asoundlib.h>
   4 #include <alsa/control.h>
   5 #include <alsa/error.h>
   6 #include <alsa/pcm.h>
   7 #include <assert.h>
   8 #include <errno.h>
   9 #include <limits.h>
  10 #include <linux/limits.h>
  11 #include <mutex>
  12 #include <pthread.h>
  13 #include <poll.h>
  14 #include <stdint.h>
  15 #include <stdio.h>
  16 #include <string>
  17 #include <sys/eventfd.h>
  18 #include <sys/inotify.h>
  19 #include <sys/poll.h>
  20 #include <thread>
  21 #include <unistd.h>
  22 #include <algorithm>
  23 #include <chrono>
  24 #include <functional>
  25 #include <iterator>
  26 #include <memory>
  27 #include <vector>
  28
  29 #include "alsa_input.h"
  30 #include "audio_mixer.h"
  31 #include "card_type.h"
  32 #include "input_mapping.h"
  33 #include "shared/shared_defs.h"
  34 #include "state.pb.h"
  35
  36 using namespace std;
  37 using namespace std::placeholders;
  38
  39 ALSAPool::ALSAPool()
  40 {
  41         should_quit_fd = eventfd(/*initval=*/0, /*flags=*/0);
  42         assert(should_quit_fd != -1);
  43 }
  44
  45 ALSAPool::~ALSAPool()
  46 {
  47         for (Device &device : devices) {
  48                 if (device.input != nullptr) {
  49                         device.input->stop_capture_thread();
  50                 }
  51         }
  52         should_quit = true;
  53         const uint64_t one = 1;
  54         if (write(should_quit_fd, &one, sizeof(one)) != sizeof(one)) {
  55                 perror("write(should_quit_fd)");
  56                 abort();
  57         }
  58         inotify_thread.join();
  59
  60         while (retry_threads_running > 0) {
  61                 this_thread::sleep_for(std::chrono::milliseconds(100));
  62         }
  63 }
  64
  65 std::vector<ALSAPool::Device> ALSAPool::get_devices()
  66 {
  67         lock_guard<mutex> lock(mu);
  68         for (Device &device : devices) {
  69                 device.held = true;
  70         }
  71         return devices;
  72 }
  73
  74 void ALSAPool::hold_device(unsigned index)
  75 {
  76         lock_guard<mutex> lock(mu);
  77         assert(index < devices.size());
  78         devices[index].held = true;
  79 }
  80
  81 void ALSAPool::release_device(unsigned index)
  82 {
  83         lock_guard<mutex> lock(mu);
  84         if (index < devices.size()) {
  85                 devices[index].held = false;
  86         }
  87 }
  88
  89 void ALSAPool::enumerate_devices()
  90 {
  91         // Enumerate all cards.
  92         for (int card_index = -1; snd_card_next(&card_index) == 0 && card_index >= 0; ) {
  93                 char address[256];
  94                 snprintf(address, sizeof(address), "hw:%d", card_index);
  95
  96                 snd_ctl_t *ctl;
  97                 int err = snd_ctl_open(&ctl, address, 0);
  98                 if (err < 0) {
  99                         printf("%s: %s\n", address, snd_strerror(err));
 100                         continue;
 101                 }
 102                 unique_ptr<snd_ctl_t, decltype(snd_ctl_close)*> ctl_closer(ctl, snd_ctl_close);
 103
 104                 // Enumerate all devices on this card.
 105                 for (int dev_index = -1; snd_ctl_pcm_next_device(ctl, &dev_index) == 0 && dev_index >= 0; ) {
 106                         probe_device_with_retry(card_index, dev_index);
 107                 }
 108         }
 109 }
 110
 111 void ALSAPool::probe_device_with_retry(unsigned card_index, unsigned dev_index)
 112 {
 113         char address[256];
 114         snprintf(address, sizeof(address), "hw:%d,%d", card_index, dev_index);
 115
 116         lock_guard<mutex> lock(add_device_mutex);
 117         if (add_device_tries_left.count(address)) {
 118                 // Some thread is already busy retrying this,
 119                 // so just reset its count.
 120                 add_device_tries_left[address] = num_retries;
 121                 return;
 122         }
 123
 124         // Try (while still holding the lock) to add the device synchronously.
 125         ProbeResult result = probe_device_once(card_index, dev_index);
 126         if (result == ProbeResult::SUCCESS) {
 127                 return;
 128         } else if (result == ProbeResult::FAILURE) {
 129                 return;
 130         }
 131         assert(result == ProbeResult::DEFER);
 132
 133         // Add failed for whatever reason (probably just that the device
 134         // isn't up yet. Set up a count so that nobody else starts a thread,
 135         // then start it ourselves.
 136         fprintf(stderr, "Trying %s again in one second...\n", address);
 137         add_device_tries_left[address] = num_retries;
 138         ++retry_threads_running;
 139         thread(&ALSAPool::probe_device_retry_thread_func, this, card_index, dev_index).detach();
 140 }
 141
 142 void ALSAPool::probe_device_retry_thread_func(unsigned card_index, unsigned dev_index)
 143 {
 144         char address[256];
 145         snprintf(address, sizeof(address), "hw:%d,%d", card_index, dev_index);
 146
 147         char thread_name[16];
 148         snprintf(thread_name, sizeof(thread_name), "Reprobe_hw:%d,%d", card_index, dev_index);
 149         pthread_setname_np(pthread_self(), thread_name);
 150
 151         for ( ;; ) {  // Termination condition within the loop.
 152                 sleep(1);
 153
 154                 // See if there are any retries left.
 155                 lock_guard<mutex> lock(add_device_mutex);
 156                 if (should_quit ||
 157                     !add_device_tries_left.count(address) ||
 158                     add_device_tries_left[address] == 0) {
 159                         add_device_tries_left.erase(address);
 160                         fprintf(stderr, "Giving up probe of %s.\n", address);
 161                         break;
 162                 }
 163
 164                 // Seemingly there were. Give it a try (we still hold the mutex).
 165                 ProbeResult result = probe_device_once(card_index, dev_index);
 166                 if (result == ProbeResult::SUCCESS) {
 167                         add_device_tries_left.erase(address);
 168                         fprintf(stderr, "Probe of %s succeeded.\n", address);
 169                         break;
 170                 } else if (result == ProbeResult::FAILURE || --add_device_tries_left[address] == 0) {
 171                         add_device_tries_left.erase(address);
 172                         fprintf(stderr, "Giving up probe of %s.\n", address);
 173                         break;
 174                 }
 175
 176                 // Failed again.
 177                 assert(result == ProbeResult::DEFER);
 178                 fprintf(stderr, "Trying %s again in one second (%d tries left)...\n",
 179                         address, add_device_tries_left[address]);
 180         }
 181
 182         --retry_threads_running;
 183 }
 184
 185 ALSAPool::ProbeResult ALSAPool::probe_device_once(unsigned card_index, unsigned dev_index)
 186 {
 187         char address[256];
 188         snprintf(address, sizeof(address), "hw:%d", card_index);
 189         snd_ctl_t *ctl;
 190         int err = snd_ctl_open(&ctl, address, 0);
 191         if (err < 0) {
 192                 printf("%s: %s\n", address, snd_strerror(err));
 193                 return ALSAPool::ProbeResult::DEFER;
 194         }
 195         unique_ptr<snd_ctl_t, decltype(snd_ctl_close)*> ctl_closer(ctl, snd_ctl_close);
 196
 197         snprintf(address, sizeof(address), "hw:%d,%d", card_index, dev_index);
 198
 199         snd_pcm_info_t *pcm_info;
 200         snd_pcm_info_alloca(&pcm_info);
 201         snd_pcm_info_set_device(pcm_info, dev_index);
 202         snd_pcm_info_set_subdevice(pcm_info, 0);
 203         snd_pcm_info_set_stream(pcm_info, SND_PCM_STREAM_CAPTURE);
 204         err = snd_ctl_pcm_info(ctl, pcm_info);
 205         if (err == -ENOENT) {
 206                 // Not a capture card.
 207                 return ALSAPool::ProbeResult::FAILURE;
 208         }
 209         if (err < 0) {
 210                 // Not available for capture.
 211                 printf("%s: Not available for capture.\n", address);
 212                 return ALSAPool::ProbeResult::DEFER;
 213         }
 214
 215         unsigned num_channels = 0;
 216
 217         // Find all channel maps for this device, and pick out the one
 218         // with the most channels.
 219         snd_pcm_chmap_query_t **cmaps = snd_pcm_query_chmaps_from_hw(card_index, dev_index, 0, SND_PCM_STREAM_CAPTURE);
 220         if (cmaps != nullptr) {
 221                 for (snd_pcm_chmap_query_t **ptr = cmaps; *ptr; ++ptr) {
 222                         num_channels = max(num_channels, (*ptr)->map.channels);
 223                 }
 224                 snd_pcm_free_chmaps(cmaps);
 225         }
 226         if (num_channels == 0) {
 227                 // Device had no channel maps. We need to open it to query.
 228                 // TODO: Do this asynchronously.
 229                 snd_pcm_t *pcm_handle;
 230                 int err = snd_pcm_open(&pcm_handle, address, SND_PCM_STREAM_CAPTURE, 0);
 231                 if (err < 0) {
 232                         printf("%s: %s\n", address, snd_strerror(err));
 233                         return ALSAPool::ProbeResult::DEFER;
 234                 }
 235                 snd_pcm_hw_params_t *hw_params;
 236                 snd_pcm_hw_params_alloca(&hw_params);
 237                 unsigned sample_rate;
 238                 if (!ALSAInput::set_base_params(address, pcm_handle, hw_params, &sample_rate)) {
 239                         snd_pcm_close(pcm_handle);
 240                         return ALSAPool::ProbeResult::DEFER;
 241                 }
 242                 err = snd_pcm_hw_params_get_channels_max(hw_params, &num_channels);
 243                 if (err < 0) {
 244                         fprintf(stderr, "[%s] snd_pcm_hw_params_get_channels_max(): %s\n",
 245                                 address, snd_strerror(err));
 246                         snd_pcm_close(pcm_handle);
 247                         return ALSAPool::ProbeResult::DEFER;
 248                 }
 249                 snd_pcm_close(pcm_handle);
 250         }
 251
 252         if (num_channels == 0) {
 253                 printf("%s: No channel maps with channels\n", address);
 254                 return ALSAPool::ProbeResult::FAILURE;
 255         }
 256
 257         snd_ctl_card_info_t *card_info;
 258         snd_ctl_card_info_alloca(&card_info);
 259         snd_ctl_card_info(ctl, card_info);
 260
 261         string name = snd_ctl_card_info_get_name(card_info);
 262         string info = snd_pcm_info_get_name(pcm_info);
 263
 264         unsigned internal_dev_index;
 265         string display_name;
 266         {
 267                 lock_guard<mutex> lock(mu);
 268                 internal_dev_index = find_free_device_index(name, info, num_channels, address);
 269                 devices[internal_dev_index].address = address;
 270                 devices[internal_dev_index].name = name;
 271                 devices[internal_dev_index].info = info;
 272                 devices[internal_dev_index].num_channels = num_channels;
 273                 // Note: Purposefully does not overwrite held.
 274
 275                 display_name = devices[internal_dev_index].display_name();
 276         }
 277
 278         reset_device(internal_dev_index);  // Restarts it if it is held (ie., we just replaced a dead card).
 279
 280         DeviceSpec spec{InputSourceType::ALSA_INPUT, internal_dev_index};
 281         global_audio_mixer->set_device_parameters(spec, display_name, CardType::LIVE_CARD, /*num_channels=*/0, /*active=*/true);  // Type and channels are ignored.
 282         global_audio_mixer->trigger_state_changed_callback();
 283
 284         return ALSAPool::ProbeResult::SUCCESS;
 285 }
 286
 287 void ALSAPool::unplug_device(unsigned card_index, unsigned dev_index)
 288 {
 289         char address[256];
 290         snprintf(address, sizeof(address), "hw:%d,%d", card_index, dev_index);
 291         for (unsigned i = 0; i < devices.size(); ++i) {
 292                 if (devices[i].state != Device::State::EMPTY &&
 293                     devices[i].state != Device::State::DEAD &&
 294                     devices[i].address == address) {
 295                         free_card(i);
 296                 }
 297         }
 298 }
 299
 300 void ALSAPool::init()
 301 {
 302         inotify_thread = thread(&ALSAPool::inotify_thread_func, this);
 303         enumerate_devices();
 304 }
 305
 306 void ALSAPool::inotify_thread_func()
 307 {
 308         pthread_setname_np(pthread_self(), "ALSA_Hotplug");
 309
 310         int inotify_fd = inotify_init();
 311         if (inotify_fd == -1) {
 312                 perror("inotify_init()");
 313                 fprintf(stderr, "No hotplug of ALSA devices available.\n");
 314                 return;
 315         }
 316
 317         int watch_fd = inotify_add_watch(inotify_fd, "/dev/snd", IN_MOVE | IN_CREATE | IN_DELETE);
 318         if (watch_fd == -1) {
 319                 perror("inotify_add_watch()");
 320                 fprintf(stderr, "No hotplug of ALSA devices available.\n");
 321                 close(inotify_fd);
 322                 return;
 323         }
 324
 325         int size = sizeof(inotify_event) + NAME_MAX + 1;
 326         unique_ptr<char[]> buf(new char[size]);
 327         while (!should_quit) {
 328                 pollfd fds[2];
 329                 fds[0].fd = inotify_fd;
 330                 fds[0].events = POLLIN;
 331                 fds[0].revents = 0;
 332                 fds[1].fd = should_quit_fd;
 333                 fds[1].events = POLLIN;
 334                 fds[1].revents = 0;
 335
 336                 int ret = poll(fds, 2, -1);
 337                 if (ret == -1) {
 338                         if (errno == EINTR) {
 339                                 continue;
 340                         } else {
 341                                 perror("poll(inotify_fd)");
 342                                 return;
 343                         }
 344                 }
 345                 if (ret == 0) {
 346                         continue;
 347                 }
 348
 349                 if (fds[1].revents) break;  // should_quit_fd asserted.
 350
 351                 ret = read(inotify_fd, buf.get(), size);
 352                 if (ret == -1) {
 353                         if (errno == EINTR) {
 354                                 continue;
 355                         } else {
 356                                 perror("read(inotify_fd)");
 357                                 close(watch_fd);
 358                                 close(inotify_fd);
 359                                 return;
 360                         }
 361                 }
 362                 if (ret < int(sizeof(inotify_event))) {
 363                         fprintf(stderr, "inotify read unexpectedly returned %d, giving up hotplug of ALSA devices.\n",
 364                                 int(ret));
 365                         close(watch_fd);
 366                         close(inotify_fd);
 367                         return;
 368                 }
 369
 370                 for (int i = 0; i < ret; ) {
 371                         const inotify_event *event = reinterpret_cast<const inotify_event *>(&buf[i]);
 372                         i += sizeof(inotify_event) + event->len;
 373
 374                         if (event->mask & IN_Q_OVERFLOW) {
 375                                 fprintf(stderr, "WARNING: inotify overflowed, may lose ALSA hotplug events.\n");
 376                                 continue;
 377                         }
 378                         unsigned card, device;
 379                         char type;
 380                         if (sscanf(event->name, "pcmC%uD%u%c", &card, &device, &type) == 3 && type == 'c') {
 381                                 if (event->mask & (IN_MOVED_FROM | IN_DELETE)) {
 382                                         printf("Deleted capture device: Card %u, device %u\n", card, device);
 383                                         unplug_device(card, device);
 384                                 }
 385                                 if (event->mask & (IN_MOVED_TO | IN_CREATE)) {
 386                                         printf("Adding capture device: Card %u, device %u\n", card, device);
 387                                         probe_device_with_retry(card, device);
 388                                 }
 389                         }
 390                 }
 391         }
 392         close(watch_fd);
 393         close(inotify_fd);
 394         close(should_quit_fd);
 395 }
 396
 397 void ALSAPool::reset_device(unsigned index)
 398 {
 399         lock_guard<mutex> lock(mu);
 400         Device *device = &devices[index];
 401         if (device->state == Device::State::DEAD) {
 402                 // Not running, and should not be started.
 403                 return;
 404         }
 405         if (inputs[index] != nullptr) {
 406                 inputs[index]->stop_capture_thread();
 407         }
 408         if (!device->held) {
 409                 inputs[index].reset();
 410         } else {
 411                 // TODO: Put on a background thread instead of locking?
 412                 auto callback = bind(&AudioMixer::add_audio, global_audio_mixer, DeviceSpec{InputSourceType::ALSA_INPUT, index}, _1, _2, _3, _4);
 413                 inputs[index].reset(new ALSAInput(device->address.c_str(), OUTPUT_FREQUENCY, device->num_channels, callback, this, index));
 414                 inputs[index]->start_capture_thread();
 415         }
 416         device->input = inputs[index].get();
 417 }
 418
 419 unsigned ALSAPool::get_capture_frequency(unsigned index)
 420 {
 421         lock_guard<mutex> lock(mu);
 422         assert(devices[index].held);
 423         if (devices[index].input)
 424                 return devices[index].input->get_sample_rate();
 425         else
 426                 return OUTPUT_FREQUENCY;
 427 }
 428
 429 ALSAPool::Device::State ALSAPool::get_card_state(unsigned index)
 430 {
 431         lock_guard<mutex> lock(mu);
 432         assert(devices[index].held);
 433         return devices[index].state;
 434 }
 435
 436 void ALSAPool::set_card_state(unsigned index, ALSAPool::Device::State state)
 437 {
 438         {
 439                 lock_guard<mutex> lock(mu);
 440                 devices[index].state = state;
 441         }
 442
 443         DeviceSpec spec{InputSourceType::ALSA_INPUT, index};
 444         bool silence = (state != ALSAPool::Device::State::RUNNING);
 445         while (!global_audio_mixer->silence_card(spec, silence))
 446                 ;
 447         global_audio_mixer->trigger_state_changed_callback();
 448 }
 449
 450 unsigned ALSAPool::find_free_device_index(const string &name, const string &info, unsigned num_channels, const string &address)
 451 {
 452         // First try to find an exact match on a dead card.
 453         for (unsigned i = 0; i < devices.size(); ++i) {
 454                 if (devices[i].state == Device::State::DEAD &&
 455                     devices[i].address == address &&
 456                     devices[i].name == name &&
 457                     devices[i].info == info &&
 458                     devices[i].num_channels == num_channels) {
 459                         devices[i].state = Device::State::READY;
 460                         return i;
 461                 }
 462         }
 463
 464         // Then try to find a match on everything but the address
 465         // (probably that devices were plugged back in a different order).
 466         // If we have two cards that are equal, this might get them mixed up,
 467         // but we don't have anything better.
 468         for (unsigned i = 0; i < devices.size(); ++i) {
 469                 if (devices[i].state == Device::State::DEAD &&
 470                     devices[i].name == name &&
 471                     devices[i].info == info &&
 472                     devices[i].num_channels == num_channels) {
 473                         devices[i].state = Device::State::READY;
 474                         return i;
 475                 }
 476         }
 477
 478         // OK, so we didn't find a match; see if there are any empty slots.
 479         for (unsigned i = 0; i < devices.size(); ++i) {
 480                 if (devices[i].state == Device::State::EMPTY) {
 481                         devices[i].state = Device::State::READY;
 482                         devices[i].held = false;
 483                         return i;
 484                 }
 485         }
 486
 487         // Failing that, we just insert the new device at the end.
 488         Device new_dev;
 489         new_dev.state = Device::State::READY;
 490         new_dev.held = false;
 491         devices.push_back(new_dev);
 492         inputs.emplace_back(nullptr);
 493         return devices.size() - 1;
 494 }
 495
 496 unsigned ALSAPool::create_dead_card(const string &name, const string &info, unsigned num_channels)
 497 {
 498         lock_guard<mutex> lock(mu);
 499
 500         // See if there are any empty slots. If not, insert one at the end.
 501         vector<Device>::iterator free_device =
 502                 find_if(devices.begin(), devices.end(),
 503                         [](const Device &device) { return device.state == Device::State::EMPTY; });
 504         if (free_device == devices.end()) {
 505                 devices.push_back(Device());
 506                 inputs.emplace_back(nullptr);
 507                 free_device = devices.end() - 1;
 508         }
 509
 510         free_device->state = Device::State::DEAD;
 511         free_device->name = name;
 512         free_device->info = info;
 513         free_device->num_channels = num_channels;
 514         free_device->held = true;
 515
 516         return distance(devices.begin(), free_device);
 517 }
 518
 519 void ALSAPool::serialize_device(unsigned index, DeviceSpecProto *serialized)
 520 {
 521         lock_guard<mutex> lock(mu);
 522         assert(index < devices.size());
 523         assert(devices[index].held);
 524         serialized->set_type(DeviceSpecProto::ALSA_INPUT);
 525         serialized->set_index(index);
 526         serialized->set_display_name(devices[index].display_name());
 527         serialized->set_alsa_name(devices[index].name);
 528         serialized->set_alsa_info(devices[index].info);
 529         serialized->set_num_channels(devices[index].num_channels);
 530         serialized->set_address(devices[index].address);
 531 }
 532
 533 void ALSAPool::free_card(unsigned index)
 534 {
 535         DeviceSpec spec{InputSourceType::ALSA_INPUT, index};
 536         while (!global_audio_mixer->silence_card(spec, true))
 537                 ;
 538
 539         {
 540                 lock_guard<mutex> lock(mu);
 541                 if (devices[index].held) {
 542                         devices[index].state = Device::State::DEAD;
 543                 } else {
 544                         devices[index].state = Device::State::EMPTY;
 545                         inputs[index].reset();
 546                 }
 547                 while (!devices.empty() && devices.back().state == Device::State::EMPTY) {
 548                         devices.pop_back();
 549                         inputs.pop_back();
 550                 }
 551         }
 552
 553         global_audio_mixer->trigger_state_changed_callback();
 554 }