} // namespace
-ALSAInput::ALSAInput(const char *device, unsigned sample_rate, unsigned num_channels, audio_callback_t audio_callback)
- : device(device), sample_rate(sample_rate), num_channels(num_channels), audio_callback(audio_callback)
+ALSAInput::ALSAInput(const char *device, unsigned sample_rate, unsigned num_channels, audio_callback_t audio_callback, ALSAPool *parent_pool, unsigned internal_dev_index)
+ : device(device),
+ sample_rate(sample_rate),
+ num_channels(num_channels),
+ audio_callback(audio_callback),
+ parent_pool(parent_pool),
+ internal_dev_index(internal_dev_index)
{
die_on_error(device, snd_pcm_open(&pcm_handle, device, SND_PCM_STREAM_CAPTURE, 0));
void ALSAInput::capture_thread_func()
{
+ parent_pool->set_card_state(internal_dev_index, ALSAPool::Device::State::STARTING);
die_on_error("snd_pcm_start()", snd_pcm_start(pcm_handle));
+ parent_pool->set_card_state(internal_dev_index, ALSAPool::Device::State::RUNNING);
+
uint64_t num_frames_output = 0;
while (!should_quit) {
int ret = snd_pcm_wait(pcm_handle, /*timeout=*/100);
} while (!success);
num_frames_output += frames;
}
+ parent_pool->free_card(internal_dev_index);
}
int64_t ALSAInput::frames_to_pts(uint64_t n) const
for (Device &device : devices) {
if (device.input != nullptr) {
device.input->stop_capture_thread();
- delete device.input;
}
}
}
// Enumerate all devices on this card.
for (int dev_index = -1; snd_ctl_pcm_next_device(ctl, &dev_index) == 0 && dev_index >= 0; ) {
- add_device(card_index, dev_index);
+ probe_device_with_retry(card_index, dev_index);
}
}
}
-bool ALSAPool::add_device(unsigned card_index, unsigned 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;
+ 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);
+
+ for ( ;; ) { // Termination condition within the loop.
+ sleep(1);
+
+ // See if there are any retries left.
+ lock_guard<mutex> lock(add_device_mutex);
+ if (!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);
+ return;
+ }
+
+ // 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);
+ return;
+ } 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);
+ return;
+ }
+
+ // Failed again.
+ assert(result == ProbeResult::DEFER);
+ fprintf(stderr, "Trying %s again in one second (%d tries left)...\n",
+ address, add_device_tries_left[address]);
+ }
+}
+
+ALSAPool::ProbeResult ALSAPool::probe_device_once(unsigned card_index, unsigned dev_index)
{
char address[256];
snprintf(address, sizeof(address), "hw:%d", card_index);
int err = snd_ctl_open(&ctl, address, 0);
if (err < 0) {
printf("%s: %s\n", address, snd_strerror(err));
- return false;
+ return ALSAPool::ProbeResult::DEFER;
}
unique_ptr<snd_ctl_t, decltype(snd_ctl_close)*> ctl_closer(ctl, snd_ctl_close);
snd_pcm_info_set_stream(pcm_info, SND_PCM_STREAM_CAPTURE);
if (snd_ctl_pcm_info(ctl, pcm_info) < 0) {
// Not available for capture.
- return false;
+ printf("%s: Not available for capture.\n", address);
+ return ALSAPool::ProbeResult::DEFER;
}
snprintf(address, sizeof(address), "hw:%d,%d", card_index, dev_index);
snd_pcm_t *pcm_handle;
int err = snd_pcm_open(&pcm_handle, address, SND_PCM_STREAM_CAPTURE, 0);
if (err < 0) {
- // TODO: When we go to hotplug support, we should support some
- // retry here, as the device could legitimately be busy.
printf("%s: %s\n", address, snd_strerror(err));
- return false;
+ return ALSAPool::ProbeResult::DEFER;
}
snd_pcm_hw_params_t *hw_params;
snd_pcm_hw_params_alloca(&hw_params);
unsigned sample_rate;
if (!set_base_params(address, pcm_handle, hw_params, &sample_rate)) {
snd_pcm_close(pcm_handle);
- return false;
+ 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 false;
+ return ALSAPool::ProbeResult::DEFER;
}
snd_pcm_close(pcm_handle);
}
if (num_channels == 0) {
printf("%s: No channel maps with channels\n", address);
- return true;
+ 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);
- Device dev;
- dev.address = address;
- dev.name = snd_ctl_card_info_get_name(card_info);
- dev.info = snd_pcm_info_get_name(pcm_info);
- dev.num_channels = num_channels;
- dev.state = Device::State::RUNNING;
-
lock_guard<mutex> lock(mu);
- devices.push_back(std::move(dev));
- return true;
+ unsigned internal_dev_index = find_free_device_index();
+ devices[internal_dev_index].address = address;
+ devices[internal_dev_index].name = snd_ctl_card_info_get_name(card_info);
+ devices[internal_dev_index].info = snd_pcm_info_get_name(pcm_info);
+ devices[internal_dev_index].num_channels = num_channels;
+ devices[internal_dev_index].state = Device::State::READY;
+
+ fprintf(stderr, "%s: Probed successfully.\n", address);
+
+ return ALSAPool::ProbeResult::SUCCESS;
}
void ALSAPool::init()
{
+ thread(&ALSAPool::inotify_thread_func, this).detach();
enumerate_devices();
}
+void ALSAPool::inotify_thread_func()
+{
+ 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]);
+ for ( ;; ) {
+ int ret = read(inotify_fd, buf.get(), size);
+ 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);
+ // TODO: Unplug.
+ }
+ 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);
+ }
+ }
+ }
+ }
+}
+
void ALSAPool::reset_device(unsigned index)
{
lock_guard<mutex> lock(mu);
inputs[index].reset();
} else {
// TODO: Put on a background thread instead of locking?
- inputs[index].reset(new ALSAInput(device->address.c_str(), OUTPUT_FREQUENCY, device->num_channels, bind(&AudioMixer::add_audio, global_audio_mixer, DeviceSpec{InputSourceType::ALSA_INPUT, index}, _1, _2, _3, _4)));
+ auto callback = bind(&AudioMixer::add_audio, global_audio_mixer, DeviceSpec{InputSourceType::ALSA_INPUT, index}, _1, _2, _3, _4);
+ 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();
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;
+}
+
+unsigned ALSAPool::find_free_device_index()
+{
+ for (unsigned i = 0; i < devices.size(); ++i) {
+ if (devices[i].state == Device::State::EMPTY) {
+ devices[i].state = Device::State::READY;
+ return i;
+ }
+ }
+ Device new_dev;
+ new_dev.state = Device::State::READY;
+ devices.push_back(new_dev);
+ inputs.emplace_back(nullptr);
+ return devices.size() - 1;
+}
+
+void ALSAPool::free_card(unsigned index)
+{
+ 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();
+ }
+}
#include <functional>
#include <string>
#include <thread>
+#include <unordered_map>
#include <vector>
#include "bmusb/bmusb.h"
#include "timebase.h"
+class ALSAPool;
+
class ALSAInput {
public:
typedef std::function<bool(const uint8_t *data, unsigned num_samples, bmusb::AudioFormat audio_format, int64_t frame_length)> audio_callback_t;
- ALSAInput(const char *device, unsigned sample_rate, unsigned num_channels, audio_callback_t audio_callback);
+ ALSAInput(const char *device, unsigned sample_rate, unsigned num_channels, audio_callback_t audio_callback, ALSAPool *parent_pool, unsigned internal_dev_index);
~ALSAInput();
// NOTE: Might very well be different from the sample rate given to the
std::thread capture_thread;
std::atomic<bool> should_quit{false};
std::unique_ptr<uint8_t[]> buffer;
+ ALSAPool *parent_pool;
+ unsigned internal_dev_index;
};
// The class dealing with the collective of all ALSA cards in the system.
// installed in place of this card, and then presumably be put
// back into STARTING or RUNNING.
DEAD
- } state;
+ } state = State::EMPTY;
std::string address; // E.g. “hw:0,0”.
std::string name, info;
// Note: The card must be held. Returns OUTPUT_FREQUENCY if the card is in EMPTY or DEAD.
unsigned get_capture_frequency(unsigned index);
+ // Note: The card must be held.
+ Device::State get_card_state(unsigned index);
+
+ // Only for ALSAInput.
+ void set_card_state(unsigned index, Device::State state);
+
+ // Just a short form for taking <mu> and then moving the card to
+ // EMPTY or DEAD state. Only for ALSAInput and for internal use.
+ void free_card(unsigned index);
+
// TODO: Add accessors and/or callbacks about changed state, so that
// the UI actually stands a chance in using that information.
std::vector<Device> devices; // Under mu.
std::vector<std::unique_ptr<ALSAInput>> inputs; // Under mu, corresponds 1:1 to devices.
+ // Keyed on device address (e.g. “hw:0,0”). If there's an entry here,
+ // it means we already have a thread doing retries, so we shouldn't
+ // start a new one.
+ std::unordered_map<std::string, unsigned> add_device_tries_left; // Under add_device_mutex.
+ std::mutex add_device_mutex;
+
+ static constexpr int num_retries = 10;
+
+ void inotify_thread_func();
void enumerate_devices();
- bool add_device(unsigned card_index, unsigned dev_index);
+
+ // Try to add an input at the given card/device. If it succeeds, return
+ // synchronously. If not, fire off a background thread to try up to
+ // <num_retries> times.
+ void probe_device_with_retry(unsigned card_index, unsigned dev_index);
+ void probe_device_retry_thread_func(unsigned card_index, unsigned dev_index);
+
+ enum class ProbeResult {
+ SUCCESS,
+ DEFER,
+ FAILURE
+ };
+ ProbeResult probe_device_once(unsigned card_index, unsigned dev_index);
+
+ // Must be called with <mu> held. Will allocate a new entry if needed.
+ // The returned entry will be set to READY state.
+ unsigned find_free_device_index();
+
+ friend class ALSAInput;
};
#endif // !defined(_ALSA_INPUT_H)
projects / nageru / commitdiff