--- /dev/null
+#include "alsa_pool.h"
+
+#include <alsa/asoundlib.h>
+#include <assert.h>
+#include <errno.h>
+#include <limits.h>
+#include <pthread.h>
+#include <poll.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <sys/eventfd.h>
+#include <sys/inotify.h>
+#include <unistd.h>
+#include <algorithm>
+#include <chrono>
+#include <functional>
+#include <iterator>
+#include <memory>
+#include <ratio>
+
+#include "alsa_input.h"
+#include "audio_mixer.h"
+#include "defs.h"
+#include "input_mapping.h"
+#include "state.pb.h"
+
+using namespace std;
+using namespace std::placeholders;
+
+ALSAPool::ALSAPool()
+{
+ should_quit_fd = eventfd(/*initval=*/0, /*flags=*/0);
+ assert(should_quit_fd != -1);
+}
+
+ALSAPool::~ALSAPool()
+{
+ for (Device &device : devices) {
+ if (device.input != nullptr) {
+ device.input->stop_capture_thread();
+ }
+ }
+ should_quit = true;
+ const uint64_t one = 1;
+ if (write(should_quit_fd, &one, sizeof(one)) != sizeof(one)) {
+ perror("write(should_quit_fd)");
+ exit(1);
+ }
+ inotify_thread.join();
+
+ while (retry_threads_running > 0) {
+ this_thread::sleep_for(std::chrono::milliseconds(100));
+ }
+}
+
+std::vector<ALSAPool::Device> ALSAPool::get_devices()
+{
+ lock_guard<mutex> lock(mu);
+ for (Device &device : devices) {
+ device.held = true;
+ }
+ return devices;
+}
+
+void ALSAPool::hold_device(unsigned index)
+{
+ lock_guard<mutex> lock(mu);
+ assert(index < devices.size());
+ devices[index].held = true;
+}
+
+void ALSAPool::release_device(unsigned index)
+{
+ lock_guard<mutex> lock(mu);
+ if (index < devices.size()) {
+ devices[index].held = false;
+ }
+}
+
+void ALSAPool::enumerate_devices()
+{
+ // Enumerate all cards.
+ for (int card_index = -1; snd_card_next(&card_index) == 0 && card_index >= 0; ) {
+ char address[256];
+ snprintf(address, sizeof(address), "hw:%d", card_index);
+
+ snd_ctl_t *ctl;
+ int err = snd_ctl_open(&ctl, address, 0);
+ if (err < 0) {
+ printf("%s: %s\n", address, snd_strerror(err));
+ continue;
+ }
+ unique_ptr<snd_ctl_t, decltype(snd_ctl_close)*> ctl_closer(ctl, snd_ctl_close);
+
+ // Enumerate all devices on this card.
+ for (int dev_index = -1; snd_ctl_pcm_next_device(ctl, &dev_index) == 0 && dev_index >= 0; ) {
+ probe_device_with_retry(card_index, dev_index);
+ }
+ }
+}
+
+void ALSAPool::probe_device_with_retry(unsigned card_index, unsigned dev_index)
+{
+ char address[256];
+ snprintf(address, sizeof(address), "hw:%d,%d", card_index, dev_index);
+
+ lock_guard<mutex> lock(add_device_mutex);
+ if (add_device_tries_left.count(address)) {
+ // Some thread is already busy retrying this,
+ // so just reset its count.
+ add_device_tries_left[address] = num_retries;
+ return;
+ }
+
+ // Try (while still holding the lock) to add the device synchronously.
+ ProbeResult result = probe_device_once(card_index, dev_index);
+ if (result == ProbeResult::SUCCESS) {
+ return;
+ } else if (result == ProbeResult::FAILURE) {
+ return;
+ }
+ assert(result == ProbeResult::DEFER);
+
+ // Add failed for whatever reason (probably just that the device
+ // isn't up yet. Set up a count so that nobody else starts a thread,
+ // then start it ourselves.
+ fprintf(stderr, "Trying %s again in one second...\n", address);
+ add_device_tries_left[address] = num_retries;
+ ++retry_threads_running;
+ thread(&ALSAPool::probe_device_retry_thread_func, this, card_index, dev_index).detach();
+}
+
+void ALSAPool::probe_device_retry_thread_func(unsigned card_index, unsigned dev_index)
+{
+ char address[256];
+ snprintf(address, sizeof(address), "hw:%d,%d", card_index, dev_index);
+
+ char thread_name[16];
+ snprintf(thread_name, sizeof(thread_name), "Reprobe_hw:%d,%d", card_index, dev_index);
+ pthread_setname_np(pthread_self(), thread_name);
+
+ for ( ;; ) { // Termination condition within the loop.
+ sleep(1);
+
+ // See if there are any retries left.
+ lock_guard<mutex> lock(add_device_mutex);
+ if (should_quit ||
+ !add_device_tries_left.count(address) ||
+ add_device_tries_left[address] == 0) {
+ add_device_tries_left.erase(address);
+ fprintf(stderr, "Giving up probe of %s.\n", address);
+ break;
+ }
+
+ // Seemingly there were. Give it a try (we still hold the mutex).
+ ProbeResult result = probe_device_once(card_index, dev_index);
+ if (result == ProbeResult::SUCCESS) {
+ add_device_tries_left.erase(address);
+ fprintf(stderr, "Probe of %s succeeded.\n", address);
+ break;
+ } else if (result == ProbeResult::FAILURE || --add_device_tries_left[address] == 0) {
+ add_device_tries_left.erase(address);
+ fprintf(stderr, "Giving up probe of %s.\n", address);
+ break;
+ }
+
+ // Failed again.
+ assert(result == ProbeResult::DEFER);
+ fprintf(stderr, "Trying %s again in one second (%d tries left)...\n",
+ address, add_device_tries_left[address]);
+ }
+
+ --retry_threads_running;
+}
+
+ALSAPool::ProbeResult ALSAPool::probe_device_once(unsigned card_index, unsigned dev_index)
+{
+ char address[256];
+ snprintf(address, sizeof(address), "hw:%d", card_index);
+ snd_ctl_t *ctl;
+ int err = snd_ctl_open(&ctl, address, 0);
+ if (err < 0) {
+ printf("%s: %s\n", address, snd_strerror(err));
+ return ALSAPool::ProbeResult::DEFER;
+ }
+ unique_ptr<snd_ctl_t, decltype(snd_ctl_close)*> ctl_closer(ctl, snd_ctl_close);
+
+ snprintf(address, sizeof(address), "hw:%d,%d", card_index, dev_index);
+
+ snd_pcm_info_t *pcm_info;
+ snd_pcm_info_alloca(&pcm_info);
+ snd_pcm_info_set_device(pcm_info, dev_index);
+ snd_pcm_info_set_subdevice(pcm_info, 0);
+ snd_pcm_info_set_stream(pcm_info, SND_PCM_STREAM_CAPTURE);
+ err = snd_ctl_pcm_info(ctl, pcm_info);
+ if (err == -ENOENT) {
+ // Not a capture card.
+ return ALSAPool::ProbeResult::FAILURE;
+ }
+ if (err < 0) {
+ // Not available for capture.
+ printf("%s: Not available for capture.\n", address);
+ return ALSAPool::ProbeResult::DEFER;
+ }
+
+ unsigned num_channels = 0;
+
+ // Find all channel maps for this device, and pick out the one
+ // with the most channels.
+ snd_pcm_chmap_query_t **cmaps = snd_pcm_query_chmaps_from_hw(card_index, dev_index, 0, SND_PCM_STREAM_CAPTURE);
+ if (cmaps != nullptr) {
+ for (snd_pcm_chmap_query_t **ptr = cmaps; *ptr; ++ptr) {
+ num_channels = max(num_channels, (*ptr)->map.channels);
+ }
+ snd_pcm_free_chmaps(cmaps);
+ }
+ if (num_channels == 0) {
+ // Device had no channel maps. We need to open it to query.
+ // TODO: Do this asynchronously.
+ snd_pcm_t *pcm_handle;
+ int err = snd_pcm_open(&pcm_handle, address, SND_PCM_STREAM_CAPTURE, 0);
+ if (err < 0) {
+ printf("%s: %s\n", address, snd_strerror(err));
+ return ALSAPool::ProbeResult::DEFER;
+ }
+ snd_pcm_hw_params_t *hw_params;
+ snd_pcm_hw_params_alloca(&hw_params);
+ unsigned sample_rate;
+ if (!ALSAInput::set_base_params(address, pcm_handle, hw_params, &sample_rate)) {
+ snd_pcm_close(pcm_handle);
+ return ALSAPool::ProbeResult::DEFER;
+ }
+ err = snd_pcm_hw_params_get_channels_max(hw_params, &num_channels);
+ if (err < 0) {
+ fprintf(stderr, "[%s] snd_pcm_hw_params_get_channels_max(): %s\n",
+ address, snd_strerror(err));
+ snd_pcm_close(pcm_handle);
+ return ALSAPool::ProbeResult::DEFER;
+ }
+ snd_pcm_close(pcm_handle);
+ }
+
+ if (num_channels == 0) {
+ printf("%s: No channel maps with channels\n", address);
+ return ALSAPool::ProbeResult::FAILURE;
+ }
+
+ snd_ctl_card_info_t *card_info;
+ snd_ctl_card_info_alloca(&card_info);
+ snd_ctl_card_info(ctl, card_info);
+
+ string name = snd_ctl_card_info_get_name(card_info);
+ string info = snd_pcm_info_get_name(pcm_info);
+
+ unsigned internal_dev_index;
+ string display_name;
+ {
+ lock_guard<mutex> lock(mu);
+ internal_dev_index = find_free_device_index(name, info, num_channels, address);
+ devices[internal_dev_index].address = address;
+ devices[internal_dev_index].name = name;
+ devices[internal_dev_index].info = info;
+ devices[internal_dev_index].num_channels = num_channels;
+ // Note: Purposefully does not overwrite held.
+
+ display_name = devices[internal_dev_index].display_name();
+ }
+
+ fprintf(stderr, "%s: Probed successfully.\n", address);
+
+ reset_device(internal_dev_index); // Restarts it if it is held (ie., we just replaced a dead card).
+
+ DeviceSpec spec{InputSourceType::ALSA_INPUT, internal_dev_index};
+ global_audio_mixer->set_display_name(spec, display_name);
+ global_audio_mixer->trigger_state_changed_callback();
+
+ return ALSAPool::ProbeResult::SUCCESS;
+}
+
+void ALSAPool::unplug_device(unsigned card_index, unsigned dev_index)
+{
+ char address[256];
+ snprintf(address, sizeof(address), "hw:%d,%d", card_index, dev_index);
+ for (unsigned i = 0; i < devices.size(); ++i) {
+ if (devices[i].state != Device::State::EMPTY &&
+ devices[i].state != Device::State::DEAD &&
+ devices[i].address == address) {
+ free_card(i);
+ }
+ }
+}
+
+void ALSAPool::init()
+{
+ inotify_thread = thread(&ALSAPool::inotify_thread_func, this);
+ enumerate_devices();
+}
+
+void ALSAPool::inotify_thread_func()
+{
+ pthread_setname_np(pthread_self(), "ALSA_Hotplug");
+
+ int inotify_fd = inotify_init();
+ if (inotify_fd == -1) {
+ perror("inotify_init()");
+ fprintf(stderr, "No hotplug of ALSA devices available.\n");
+ return;
+ }
+
+ int watch_fd = inotify_add_watch(inotify_fd, "/dev/snd", IN_MOVE | IN_CREATE | IN_DELETE);
+ if (watch_fd == -1) {
+ perror("inotify_add_watch()");
+ fprintf(stderr, "No hotplug of ALSA devices available.\n");
+ close(inotify_fd);
+ return;
+ }
+
+ int size = sizeof(inotify_event) + NAME_MAX + 1;
+ unique_ptr<char[]> buf(new char[size]);
+ while (!should_quit) {
+ pollfd fds[2];
+ fds[0].fd = inotify_fd;
+ fds[0].events = POLLIN;
+ fds[0].revents = 0;
+ fds[1].fd = should_quit_fd;
+ fds[1].events = POLLIN;
+ fds[1].revents = 0;
+
+ int ret = poll(fds, 2, -1);
+ if (ret == -1) {
+ if (errno == EINTR) {
+ continue;
+ } else {
+ perror("poll(inotify_fd)");
+ return;
+ }
+ }
+ if (ret == 0) {
+ continue;
+ }
+
+ if (fds[1].revents) break; // should_quit_fd asserted.
+
+ ret = read(inotify_fd, buf.get(), size);
+ if (ret == -1) {
+ if (errno == EINTR) {
+ continue;
+ } else {
+ perror("read(inotify_fd)");
+ close(watch_fd);
+ close(inotify_fd);
+ return;
+ }
+ }
+ if (ret < int(sizeof(inotify_event))) {
+ fprintf(stderr, "inotify read unexpectedly returned %d, giving up hotplug of ALSA devices.\n",
+ int(ret));
+ close(watch_fd);
+ close(inotify_fd);
+ return;
+ }
+
+ for (int i = 0; i < ret; ) {
+ const inotify_event *event = reinterpret_cast<const inotify_event *>(&buf[i]);
+ i += sizeof(inotify_event) + event->len;
+
+ if (event->mask & IN_Q_OVERFLOW) {
+ fprintf(stderr, "WARNING: inotify overflowed, may lose ALSA hotplug events.\n");
+ continue;
+ }
+ unsigned card, device;
+ char type;
+ if (sscanf(event->name, "pcmC%uD%u%c", &card, &device, &type) == 3 && type == 'c') {
+ if (event->mask & (IN_MOVED_FROM | IN_DELETE)) {
+ printf("Deleted capture device: Card %u, device %u\n", card, device);
+ unplug_device(card, device);
+ }
+ if (event->mask & (IN_MOVED_TO | IN_CREATE)) {
+ printf("Adding capture device: Card %u, device %u\n", card, device);
+ probe_device_with_retry(card, device);
+ }
+ }
+ }
+ }
+ close(watch_fd);
+ close(inotify_fd);
+ close(should_quit_fd);
+}
+
+void ALSAPool::reset_device(unsigned index)
+{
+ lock_guard<mutex> lock(mu);
+ Device *device = &devices[index];
+ if (device->state == Device::State::DEAD) {
+ // Not running, and should not be started.
+ return;
+ }
+ if (inputs[index] != nullptr) {
+ inputs[index]->stop_capture_thread();
+ }
+ if (!device->held) {
+ inputs[index].reset();
+ } else {
+ // TODO: Put on a background thread instead of locking?
+ auto callback = bind(&AudioMixer::add_audio, global_audio_mixer, DeviceSpec{InputSourceType::ALSA_INPUT, index}, _1, _2, _3, _4, _5);
+ inputs[index].reset(new ALSAInput(device->address.c_str(), OUTPUT_FREQUENCY, device->num_channels, callback, this, index));
+ inputs[index]->start_capture_thread();
+ }
+ device->input = inputs[index].get();
+}
+
+unsigned ALSAPool::get_capture_frequency(unsigned index)
+{
+ lock_guard<mutex> lock(mu);
+ assert(devices[index].held);
+ if (devices[index].input)
+ return devices[index].input->get_sample_rate();
+ else
+ return OUTPUT_FREQUENCY;
+}
+
+ALSAPool::Device::State ALSAPool::get_card_state(unsigned index)
+{
+ lock_guard<mutex> lock(mu);
+ assert(devices[index].held);
+ return devices[index].state;
+}
+
+void ALSAPool::set_card_state(unsigned index, ALSAPool::Device::State state)
+{
+ {
+ lock_guard<mutex> lock(mu);
+ devices[index].state = state;
+ }
+
+ DeviceSpec spec{InputSourceType::ALSA_INPUT, index};
+ bool silence = (state != ALSAPool::Device::State::RUNNING);
+ while (!global_audio_mixer->silence_card(spec, silence))
+ ;
+ global_audio_mixer->trigger_state_changed_callback();
+}
+
+unsigned ALSAPool::find_free_device_index(const string &name, const string &info, unsigned num_channels, const string &address)
+{
+ // First try to find an exact match on a dead card.
+ for (unsigned i = 0; i < devices.size(); ++i) {
+ if (devices[i].state == Device::State::DEAD &&
+ devices[i].address == address &&
+ devices[i].name == name &&
+ devices[i].info == info &&
+ devices[i].num_channels == num_channels) {
+ devices[i].state = Device::State::READY;
+ return i;
+ }
+ }
+
+ // Then try to find a match on everything but the address
+ // (probably that devices were plugged back in a different order).
+ // If we have two cards that are equal, this might get them mixed up,
+ // but we don't have anything better.
+ for (unsigned i = 0; i < devices.size(); ++i) {
+ if (devices[i].state == Device::State::DEAD &&
+ devices[i].name == name &&
+ devices[i].info == info &&
+ devices[i].num_channels == num_channels) {
+ devices[i].state = Device::State::READY;
+ return i;
+ }
+ }
+
+ // OK, so we didn't find a match; see if there are any empty slots.
+ for (unsigned i = 0; i < devices.size(); ++i) {
+ if (devices[i].state == Device::State::EMPTY) {
+ devices[i].state = Device::State::READY;
+ devices[i].held = false;
+ return i;
+ }
+ }
+
+ // Failing that, we just insert the new device at the end.
+ Device new_dev;
+ new_dev.state = Device::State::READY;
+ new_dev.held = false;
+ devices.push_back(new_dev);
+ inputs.emplace_back(nullptr);
+ return devices.size() - 1;
+}
+
+unsigned ALSAPool::create_dead_card(const string &name, const string &info, unsigned num_channels)
+{
+ lock_guard<mutex> lock(mu);
+
+ // See if there are any empty slots. If not, insert one at the end.
+ vector<Device>::iterator free_device =
+ find_if(devices.begin(), devices.end(),
+ [](const Device &device) { return device.state == Device::State::EMPTY; });
+ if (free_device == devices.end()) {
+ devices.push_back(Device());
+ inputs.emplace_back(nullptr);
+ free_device = devices.end() - 1;
+ }
+
+ free_device->state = Device::State::DEAD;
+ free_device->name = name;
+ free_device->info = info;
+ free_device->num_channels = num_channels;
+ free_device->held = true;
+
+ return distance(devices.begin(), free_device);
+}
+
+void ALSAPool::serialize_device(unsigned index, DeviceSpecProto *serialized)
+{
+ lock_guard<mutex> lock(mu);
+ assert(index < devices.size());
+ assert(devices[index].held);
+ serialized->set_type(DeviceSpecProto::ALSA_INPUT);
+ serialized->set_index(index);
+ serialized->set_display_name(devices[index].display_name());
+ serialized->set_alsa_name(devices[index].name);
+ serialized->set_alsa_info(devices[index].info);
+ serialized->set_num_channels(devices[index].num_channels);
+ serialized->set_address(devices[index].address);
+}
+
+void ALSAPool::free_card(unsigned index)
+{
+ DeviceSpec spec{InputSourceType::ALSA_INPUT, index};
+ while (!global_audio_mixer->silence_card(spec, true))
+ ;
+
+ {
+ lock_guard<mutex> lock(mu);
+ if (devices[index].held) {
+ devices[index].state = Device::State::DEAD;
+ } else {
+ devices[index].state = Device::State::EMPTY;
+ inputs[index].reset();
+ }
+ while (!devices.empty() && devices.back().state == Device::State::EMPTY) {
+ devices.pop_back();
+ inputs.pop_back();
+ }
+ }
+
+ global_audio_mixer->trigger_state_changed_callback();
+}
projects / nageru / blobdiff