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

   1 #include "alsa_pool.h"
   2
   3 #include <alsa/asoundlib.h>
   4 #include <assert.h>
   5 #include <errno.h>
   6 #include <limits.h>
   7 #include <pthread.h>
   8 #include <poll.h>
   9 #include <stdint.h>
  10 #include <stdio.h>
  11 #include <sys/eventfd.h>
  12 #include <sys/inotify.h>
  13 #include <unistd.h>
  14 #include <algorithm>
  15 #include <chrono>
  16 #include <functional>
  17 #include <iterator>
  18 #include <memory>
  19 #include <ratio>
  20
  21 #include "alsa_input.h"
  22 #include "audio_mixer.h"
  23 #include "defs.h"
  24 #include "input_mapping.h"
  25 #include "state.pb.h"
  26
  27 using namespace std;
  28 using namespace std::placeholders;
  29
  30 ALSAPool::ALSAPool()
  31 {
  32         should_quit_fd = eventfd(/*initval=*/0, /*flags=*/0);
  33         assert(should_quit_fd != -1);
  34 }
  35
  36 ALSAPool::~ALSAPool()
  37 {
  38         for (Device &device : devices) {
  39                 if (device.input != nullptr) {
  40                         device.input->stop_capture_thread();
  41                 }
  42         }
  43         should_quit = true;
  44         const uint64_t one = 1;
  45         if (write(should_quit_fd, &one, sizeof(one)) != sizeof(one)) {
  46                 perror("write(should_quit_fd)");
  47                 abort();
  48         }
  49         inotify_thread.join();
  50
  51         while (retry_threads_running > 0) {
  52                 this_thread::sleep_for(std::chrono::milliseconds(100));
  53         }
  54 }
  55
  56 std::vector<ALSAPool::Device> ALSAPool::get_devices(bool hold_devices)
  57 {
  58         lock_guard<mutex> lock(mu);
  59         if (hold_devices) {
  60                 for (Device &device : devices) {
  61                         device.held = true;
  62                 }
  63         }
  64         return devices;
  65 }
  66
  67 void ALSAPool::hold_device(unsigned index)
  68 {
  69         lock_guard<mutex> lock(mu);
  70         assert(index < devices.size());
  71         devices[index].held = true;
  72 }
  73
  74 void ALSAPool::release_device(unsigned index)
  75 {
  76         lock_guard<mutex> lock(mu);
  77         if (index < devices.size()) {
  78                 devices[index].held = false;
  79         }
  80 }
  81
  82 bool ALSAPool::device_is_held(unsigned index)
  83 {
  84         lock_guard<mutex> lock(mu);
  85         if (index < devices.size()) {
  86                 return devices[index].held;
  87         } else {
  88                 return false;
  89         }
  90 }
  91
  92 void ALSAPool::enumerate_devices()
  93 {
  94         // Enumerate all cards.
  95         for (int card_index = -1; snd_card_next(&card_index) == 0 && card_index >= 0; ) {
  96                 char address[256];
  97                 snprintf(address, sizeof(address), "hw:%d", card_index);
  98
  99                 snd_ctl_t *ctl;
 100                 int err = snd_ctl_open(&ctl, address, 0);
 101                 if (err < 0) {
 102                         printf("%s: %s\n", address, snd_strerror(err));
 103                         continue;
 104                 }
 105                 unique_ptr<snd_ctl_t, decltype(snd_ctl_close)*> ctl_closer(ctl, snd_ctl_close);
 106
 107                 // Enumerate all devices on this card.
 108                 for (int dev_index = -1; snd_ctl_pcm_next_device(ctl, &dev_index) == 0 && dev_index >= 0; ) {
 109                         probe_device_with_retry(card_index, dev_index);
 110                 }
 111         }
 112 }
 113
 114 void ALSAPool::probe_device_with_retry(unsigned card_index, unsigned dev_index)
 115 {
 116         char address[256];
 117         snprintf(address, sizeof(address), "hw:%d,%d", card_index, dev_index);
 118
 119         lock_guard<mutex> lock(add_device_mutex);
 120         if (add_device_tries_left.count(address)) {
 121                 // Some thread is already busy retrying this,
 122                 // so just reset its count.
 123                 add_device_tries_left[address] = num_retries;
 124                 return;
 125         }
 126
 127         // Try (while still holding the lock) to add the device synchronously.
 128         ProbeResult result = probe_device_once(card_index, dev_index);
 129         if (result == ProbeResult::SUCCESS) {
 130                 return;
 131         } else if (result == ProbeResult::FAILURE) {
 132                 return;
 133         }
 134         assert(result == ProbeResult::DEFER);
 135
 136         // Add failed for whatever reason (probably just that the device
 137         // isn't up yet. Set up a count so that nobody else starts a thread,
 138         // then start it ourselves.
 139         fprintf(stderr, "Trying %s again in one second...\n", address);
 140         add_device_tries_left[address] = num_retries;
 141         ++retry_threads_running;
 142         thread(&ALSAPool::probe_device_retry_thread_func, this, card_index, dev_index).detach();
 143 }
 144
 145 void ALSAPool::probe_device_retry_thread_func(unsigned card_index, unsigned dev_index)
 146 {
 147         char address[256];
 148         snprintf(address, sizeof(address), "hw:%d,%d", card_index, dev_index);
 149
 150         char thread_name[16];
 151         snprintf(thread_name, sizeof(thread_name), "Reprobe_hw:%d,%d", card_index, dev_index);
 152         pthread_setname_np(pthread_self(), thread_name);
 153
 154         for ( ;; ) {  // Termination condition within the loop.
 155                 sleep(1);
 156
 157                 // See if there are any retries left.
 158                 lock_guard<mutex> lock(add_device_mutex);
 159                 if (should_quit ||
 160                     !add_device_tries_left.count(address) ||
 161                     add_device_tries_left[address] == 0) {
 162                         add_device_tries_left.erase(address);
 163                         fprintf(stderr, "Giving up probe of %s.\n", address);
 164                         break;
 165                 }
 166
 167                 // Seemingly there were. Give it a try (we still hold the mutex).
 168                 ProbeResult result = probe_device_once(card_index, dev_index);
 169                 if (result == ProbeResult::SUCCESS) {
 170                         add_device_tries_left.erase(address);
 171                         fprintf(stderr, "Probe of %s succeeded.\n", address);
 172                         break;
 173                 } else if (result == ProbeResult::FAILURE || --add_device_tries_left[address] == 0) {
 174                         add_device_tries_left.erase(address);
 175                         fprintf(stderr, "Giving up probe of %s.\n", address);
 176                         break;
 177                 }
 178
 179                 // Failed again.
 180                 assert(result == ProbeResult::DEFER);
 181                 fprintf(stderr, "Trying %s again in one second (%d tries left)...\n",
 182                         address, add_device_tries_left[address]);
 183         }
 184
 185         --retry_threads_running;
 186 }
 187
 188 ALSAPool::ProbeResult ALSAPool::probe_device_once(unsigned card_index, unsigned dev_index)
 189 {
 190         char address[256];
 191         snprintf(address, sizeof(address), "hw:%d", card_index);
 192         snd_ctl_t *ctl;
 193         int err = snd_ctl_open(&ctl, address, 0);
 194         if (err < 0) {
 195                 printf("%s: %s\n", address, snd_strerror(err));
 196                 return ALSAPool::ProbeResult::DEFER;
 197         }
 198         unique_ptr<snd_ctl_t, decltype(snd_ctl_close)*> ctl_closer(ctl, snd_ctl_close);
 199
 200         snprintf(address, sizeof(address), "hw:%d,%d", card_index, dev_index);
 201
 202         snd_pcm_info_t *pcm_info;
 203         snd_pcm_info_alloca(&pcm_info);
 204         snd_pcm_info_set_device(pcm_info, dev_index);
 205         snd_pcm_info_set_subdevice(pcm_info, 0);
 206         snd_pcm_info_set_stream(pcm_info, SND_PCM_STREAM_CAPTURE);
 207         err = snd_ctl_pcm_info(ctl, pcm_info);
 208         if (err == -ENOENT) {
 209                 // Not a capture card.
 210                 return ALSAPool::ProbeResult::FAILURE;
 211         }
 212         if (err < 0) {
 213                 // Not available for capture.
 214                 printf("%s: Not available for capture.\n", address);
 215                 return ALSAPool::ProbeResult::DEFER;
 216         }
 217
 218         unsigned num_channels = 0;
 219
 220         // Find all channel maps for this device, and pick out the one
 221         // with the most channels.
 222         snd_pcm_chmap_query_t **cmaps = snd_pcm_query_chmaps_from_hw(card_index, dev_index, 0, SND_PCM_STREAM_CAPTURE);
 223         if (cmaps != nullptr) {
 224                 for (snd_pcm_chmap_query_t **ptr = cmaps; *ptr; ++ptr) {
 225                         num_channels = max(num_channels, (*ptr)->map.channels);
 226                 }
 227                 snd_pcm_free_chmaps(cmaps);
 228         }
 229         if (num_channels == 0) {
 230                 // Device had no channel maps. We need to open it to query.
 231                 // TODO: Do this asynchronously.
 232                 snd_pcm_t *pcm_handle;
 233                 int err = snd_pcm_open(&pcm_handle, address, SND_PCM_STREAM_CAPTURE, 0);
 234                 if (err < 0) {
 235                         printf("%s: %s\n", address, snd_strerror(err));
 236                         return ALSAPool::ProbeResult::DEFER;
 237                 }
 238                 snd_pcm_hw_params_t *hw_params;
 239                 snd_pcm_hw_params_alloca(&hw_params);
 240                 unsigned sample_rate;
 241                 if (!ALSAInput::set_base_params(address, pcm_handle, hw_params, &sample_rate)) {
 242                         snd_pcm_close(pcm_handle);
 243                         return ALSAPool::ProbeResult::DEFER;
 244                 }
 245                 err = snd_pcm_hw_params_get_channels_max(hw_params, &num_channels);
 246                 if (err < 0) {
 247                         fprintf(stderr, "[%s] snd_pcm_hw_params_get_channels_max(): %s\n",
 248                                 address, snd_strerror(err));
 249                         snd_pcm_close(pcm_handle);
 250                         return ALSAPool::ProbeResult::DEFER;
 251                 }
 252                 snd_pcm_close(pcm_handle);
 253         }
 254
 255         if (num_channels == 0) {
 256                 printf("%s: No channel maps with channels\n", address);
 257                 return ALSAPool::ProbeResult::FAILURE;
 258         }
 259
 260         snd_ctl_card_info_t *card_info;
 261         snd_ctl_card_info_alloca(&card_info);
 262         snd_ctl_card_info(ctl, card_info);
 263
 264         string name = snd_ctl_card_info_get_name(card_info);
 265         string info = snd_pcm_info_get_name(pcm_info);
 266
 267         unsigned internal_dev_index;
 268         string display_name;
 269         {
 270                 lock_guard<mutex> lock(mu);
 271                 internal_dev_index = find_free_device_index(name, info, num_channels, address);
 272                 devices[internal_dev_index].address = address;
 273                 devices[internal_dev_index].name = name;
 274                 devices[internal_dev_index].info = info;
 275                 devices[internal_dev_index].num_channels = num_channels;
 276                 // Note: Purposefully does not overwrite held.
 277
 278                 display_name = devices[internal_dev_index].display_name();
 279         }
 280
 281         fprintf(stderr, "%s: Probed successfully.\n", address);
 282
 283         reset_device(internal_dev_index);  // Restarts it if it is held (ie., we just replaced a dead card).
 284
 285         DeviceSpec spec{InputSourceType::ALSA_INPUT, internal_dev_index};
 286         global_audio_mixer->set_display_name(spec, display_name);
 287         global_audio_mixer->trigger_state_changed_callback();
 288
 289         return ALSAPool::ProbeResult::SUCCESS;
 290 }
 291
 292 void ALSAPool::unplug_device(unsigned card_index, unsigned dev_index)
 293 {
 294         char address[256];
 295         snprintf(address, sizeof(address), "hw:%d,%d", card_index, dev_index);
 296         for (unsigned i = 0; i < devices.size(); ++i) {
 297                 if (devices[i].state != Device::State::EMPTY &&
 298                     devices[i].state != Device::State::DEAD &&
 299                     devices[i].address == address) {
 300                         free_card(i);
 301                 }
 302         }
 303 }
 304
 305 void ALSAPool::init()
 306 {
 307         inotify_thread = thread(&ALSAPool::inotify_thread_func, this);
 308         enumerate_devices();
 309 }
 310
 311 void ALSAPool::inotify_thread_func()
 312 {
 313         pthread_setname_np(pthread_self(), "ALSA_Hotplug");
 314
 315         int inotify_fd = inotify_init();
 316         if (inotify_fd == -1) {
 317                 perror("inotify_init()");
 318                 fprintf(stderr, "No hotplug of ALSA devices available.\n");
 319                 return;
 320         }
 321
 322         int watch_fd = inotify_add_watch(inotify_fd, "/dev/snd", IN_MOVE | IN_CREATE | IN_DELETE);
 323         if (watch_fd == -1) {
 324                 perror("inotify_add_watch()");
 325                 fprintf(stderr, "No hotplug of ALSA devices available.\n");
 326                 close(inotify_fd);
 327                 return;
 328         }
 329
 330         int size = sizeof(inotify_event) + NAME_MAX + 1;
 331         unique_ptr<char[]> buf(new char[size]);
 332         while (!should_quit) {
 333                 pollfd fds[2];
 334                 fds[0].fd = inotify_fd;
 335                 fds[0].events = POLLIN;
 336                 fds[0].revents = 0;
 337                 fds[1].fd = should_quit_fd;
 338                 fds[1].events = POLLIN;
 339                 fds[1].revents = 0;
 340
 341                 int ret = poll(fds, 2, -1);
 342                 if (ret == -1) {
 343                         if (errno == EINTR) {
 344                                 continue;
 345                         } else {
 346                                 perror("poll(inotify_fd)");
 347                                 return;
 348                         }
 349                 }
 350                 if (ret == 0) {
 351                         continue;
 352                 }
 353
 354                 if (fds[1].revents) break;  // should_quit_fd asserted.
 355
 356                 ret = read(inotify_fd, buf.get(), size);
 357                 if (ret == -1) {
 358                         if (errno == EINTR) {
 359                                 continue;
 360                         } else {
 361                                 perror("read(inotify_fd)");
 362                                 close(watch_fd);
 363                                 close(inotify_fd);
 364                                 return;
 365                         }
 366                 }
 367                 if (ret < int(sizeof(inotify_event))) {
 368                         fprintf(stderr, "inotify read unexpectedly returned %d, giving up hotplug of ALSA devices.\n",
 369                                 int(ret));
 370                         close(watch_fd);
 371                         close(inotify_fd);
 372                         return;
 373                 }
 374
 375                 for (int i = 0; i < ret; ) {
 376                         const inotify_event *event = reinterpret_cast<const inotify_event *>(&buf[i]);
 377                         i += sizeof(inotify_event) + event->len;
 378
 379                         if (event->mask & IN_Q_OVERFLOW) {
 380                                 fprintf(stderr, "WARNING: inotify overflowed, may lose ALSA hotplug events.\n");
 381                                 continue;
 382                         }
 383                         unsigned card, device;
 384                         char type;
 385                         if (sscanf(event->name, "pcmC%uD%u%c", &card, &device, &type) == 3 && type == 'c') {
 386                                 if (event->mask & (IN_MOVED_FROM | IN_DELETE)) {
 387                                         printf("Deleted capture device: Card %u, device %u\n", card, device);
 388                                         unplug_device(card, device);
 389                                 }
 390                                 if (event->mask & (IN_MOVED_TO | IN_CREATE)) {
 391                                         printf("Adding capture device: Card %u, device %u\n", card, device);
 392                                         probe_device_with_retry(card, device);
 393                                 }
 394                         }
 395                 }
 396         }
 397         close(watch_fd);
 398         close(inotify_fd);
 399         close(should_quit_fd);
 400 }
 401
 402 void ALSAPool::reset_device(unsigned index)
 403 {
 404         lock_guard<mutex> lock(mu);
 405         Device *device = &devices[index];
 406         if (device->state == Device::State::DEAD) {
 407                 // Not running, and should not be started.
 408                 return;
 409         }
 410         if (inputs[index] != nullptr) {
 411                 inputs[index]->stop_capture_thread();
 412         }
 413         if (!device->held) {
 414                 inputs[index].reset();
 415         } else {
 416                 // TODO: Put on a background thread instead of locking?
 417                 auto callback = bind(&AudioMixer::add_audio, global_audio_mixer, DeviceSpec{InputSourceType::ALSA_INPUT, index}, _1, _2, _3, _4);
 418                 inputs[index].reset(new ALSAInput(device->address.c_str(), OUTPUT_FREQUENCY, device->num_channels, callback, this, index));
 419                 inputs[index]->start_capture_thread();
 420         }
 421         device->input = inputs[index].get();
 422 }
 423
 424 unsigned ALSAPool::get_capture_frequency(unsigned index)
 425 {
 426         lock_guard<mutex> lock(mu);
 427         assert(devices[index].held);
 428         if (devices[index].input)
 429                 return devices[index].input->get_sample_rate();
 430         else
 431                 return OUTPUT_FREQUENCY;
 432 }
 433
 434 ALSAPool::Device::State ALSAPool::get_card_state(unsigned index)
 435 {
 436         lock_guard<mutex> lock(mu);
 437         assert(devices[index].held);
 438         return devices[index].state;
 439 }
 440
 441 void ALSAPool::set_card_state(unsigned index, ALSAPool::Device::State state)
 442 {
 443         {
 444                 lock_guard<mutex> lock(mu);
 445                 devices[index].state = state;
 446         }
 447
 448         DeviceSpec spec{InputSourceType::ALSA_INPUT, index};
 449         bool silence = (state != ALSAPool::Device::State::RUNNING);
 450         while (!global_audio_mixer->silence_card(spec, silence))
 451                 ;
 452         global_audio_mixer->trigger_state_changed_callback();
 453 }
 454
 455 unsigned ALSAPool::find_free_device_index(const string &name, const string &info, unsigned num_channels, const string &address)
 456 {
 457         // First try to find an exact match on a dead card.
 458         for (unsigned i = 0; i < devices.size(); ++i) {
 459                 if (devices[i].state == Device::State::DEAD &&
 460                     devices[i].address == address &&
 461                     devices[i].name == name &&
 462                     devices[i].info == info &&
 463                     devices[i].num_channels == num_channels) {
 464                         devices[i].state = Device::State::READY;
 465                         return i;
 466                 }
 467         }
 468
 469         // Then try to find a match on everything but the address
 470         // (probably that devices were plugged back in a different order).
 471         // If we have two cards that are equal, this might get them mixed up,
 472         // but we don't have anything better.
 473         for (unsigned i = 0; i < devices.size(); ++i) {
 474                 if (devices[i].state == Device::State::DEAD &&
 475                     devices[i].name == name &&
 476                     devices[i].info == info &&
 477                     devices[i].num_channels == num_channels) {
 478                         devices[i].state = Device::State::READY;
 479                         return i;
 480                 }
 481         }
 482
 483         // OK, so we didn't find a match; see if there are any empty slots.
 484         for (unsigned i = 0; i < devices.size(); ++i) {
 485                 if (devices[i].state == Device::State::EMPTY) {
 486                         devices[i].state = Device::State::READY;
 487                         devices[i].held = false;
 488                         return i;
 489                 }
 490         }
 491
 492         // Failing that, we just insert the new device at the end.
 493         Device new_dev;
 494         new_dev.state = Device::State::READY;
 495         new_dev.held = false;
 496         devices.push_back(new_dev);
 497         inputs.emplace_back(nullptr);
 498         return devices.size() - 1;
 499 }
 500
 501 unsigned ALSAPool::create_dead_card(const string &name, const string &info, unsigned num_channels)
 502 {
 503         lock_guard<mutex> lock(mu);
 504
 505         // See if there are any empty slots. If not, insert one at the end.
 506         vector<Device>::iterator free_device =
 507                 find_if(devices.begin(), devices.end(),
 508                         [](const Device &device) { return device.state == Device::State::EMPTY; });
 509         if (free_device == devices.end()) {
 510                 devices.push_back(Device());
 511                 inputs.emplace_back(nullptr);
 512                 free_device = devices.end() - 1;
 513         }
 514
 515         free_device->state = Device::State::DEAD;
 516         free_device->name = name;
 517         free_device->info = info;
 518         free_device->num_channels = num_channels;
 519         free_device->held = true;
 520
 521         return distance(devices.begin(), free_device);
 522 }
 523
 524 void ALSAPool::serialize_device(unsigned index, DeviceSpecProto *serialized)
 525 {
 526         lock_guard<mutex> lock(mu);
 527         assert(index < devices.size());
 528         assert(devices[index].held);
 529         serialized->set_type(DeviceSpecProto::ALSA_INPUT);
 530         serialized->set_index(index);
 531         serialized->set_display_name(devices[index].display_name());
 532         serialized->set_alsa_name(devices[index].name);
 533         serialized->set_alsa_info(devices[index].info);
 534         serialized->set_num_channels(devices[index].num_channels);
 535         serialized->set_address(devices[index].address);
 536 }
 537
 538 void ALSAPool::free_card(unsigned index)
 539 {
 540         DeviceSpec spec{InputSourceType::ALSA_INPUT, index};
 541         while (!global_audio_mixer->silence_card(spec, true))
 542                 ;
 543
 544         {
 545                 lock_guard<mutex> lock(mu);
 546                 if (devices[index].held) {
 547                         devices[index].state = Device::State::DEAD;
 548                 } else {
 549                         devices[index].state = Device::State::EMPTY;
 550                         inputs[index].reset();
 551                 }
 552                 while (!devices.empty() && devices.back().state == Device::State::EMPTY) {
 553                         devices.pop_back();
 554                         inputs.pop_back();
 555                 }
 556         }
 557
 558         global_audio_mixer->trigger_state_changed_callback();
 559 }