src/media/audio/audio_core/audio_device.cc

// Copyright 2017 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "src/media/audio/audio_core/audio_device.h"

#include <lib/fit/bridge.h>

#include <trace/event.h>

#include "src/media/audio/audio_core/audio_device_manager.h"
#include "src/media/audio/audio_core/audio_driver.h"
#include "src/media/audio/audio_core/audio_output.h"
#include "src/media/audio/audio_core/utils.h"

namespace media::audio {
namespace {

constexpr float kDefaultDeviceGain = 0.;

}  // namespace

// static
std::string AudioDevice::UniqueIdToString(const audio_stream_unique_id_t& id) {
  static_assert(sizeof(id.data) == 16, "Unexpected unique ID size");
  char buf[(sizeof(id.data) * 2) + 1];

  const auto& d = id.data;
  snprintf(buf, sizeof(buf), "%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",
           d[0], d[1], d[2], d[3], d[4], d[5], d[6], d[7], d[8], d[9], d[10], d[11], d[12], d[13],
           d[14], d[15]);
  return std::string(buf, sizeof(buf) - 1);
}

// static
fit::result<audio_stream_unique_id_t> AudioDevice::UniqueIdFromString(const std::string& id) {
  if (id.size() != 32) {
    return fit::error();
  }

  audio_stream_unique_id_t unique_id;
  auto& d = unique_id.data;
  const auto captured =
      sscanf(id.c_str(),
             "%2hhx%2hhx%2hhx%2hhx%2hhx%2hhx%2hhx%2hhx%2hhx%2hhx%2hhx%2hhx%2hhx%2hhx%2hhx%2hhx",
             &d[0], &d[1], &d[2], &d[3], &d[4], &d[5], &d[6], &d[7], &d[8], &d[9], &d[10], &d[11],
             &d[12], &d[13], &d[14], &d[15]);
  if (captured != 16) {
    return fit::error();
  }

  return fit::ok(unique_id);
}

AudioDevice::AudioDevice(AudioObject::Type type, ThreadingModel* threading_model,
                         DeviceRegistry* registry, LinkMatrix* link_matrix)
    : AudioObject(type),
      device_registry_(*registry),
      threading_model_(*threading_model),
      mix_domain_(threading_model->AcquireMixDomain()),
      driver_(new AudioDriver(this)),
      link_matrix_(*link_matrix) {
  FX_DCHECK(registry);
  FX_DCHECK((type == Type::Input) || (type == Type::Output));
  FX_DCHECK(link_matrix);

  EstablishReferenceClock();
}

void AudioDevice::EstablishReferenceClock() {
  // This clock can be created at AudioDevice ctor time, but once we receive details from the driver
  // (such as whether the device is in the monotonic clock domain), we may transition this to become
  // a recovered clock that tracks the device's DMA progress across the ring buffer.
  auto status =
      zx::clock::create(ZX_CLOCK_OPT_MONOTONIC | ZX_CLOCK_OPT_CONTINUOUS | ZX_CLOCK_OPT_AUTO_START,
                        nullptr, &ref_clock_);
  FX_DCHECK(status == ZX_OK);
}

AudioDevice::~AudioDevice() = default;

std::optional<Format> AudioDevice::format() const {
  auto _driver = driver();
  if (!_driver) {
    return std::nullopt;
  }
  return _driver->GetFormat();
}

void AudioDevice::Wakeup() {
  TRACE_DURATION("audio", "AudioDevice::Wakeup");
  mix_wakeup_.Signal();
}

uint64_t AudioDevice::token() const {
  return driver_ ? driver_->stream_channel_koid() : ZX_KOID_INVALID;
}

// Change a device's gain, propagating the change to the affected links.
void AudioDevice::SetGainInfo(const fuchsia::media::AudioGainInfo& info, uint32_t set_flags) {
  TRACE_DURATION("audio", "AudioDevice::SetGainInfo");
  // Limit the request to what the hardware can support
  fuchsia::media::AudioGainInfo limited = info;
  ApplyGainLimits(&limited, set_flags);

  // For outputs, change the gain of all links where it is the destination.
  if (is_output()) {
    link_matrix_.ForEachSourceLink(*this, [&limited](LinkMatrix::LinkHandle link) {
      if (link.object->type() == AudioObject::Type::AudioRenderer) {
        const auto muted = limited.flags & fuchsia::media::AudioGainInfoFlag_Mute;
        link.mixer->bookkeeping().gain.SetDestGain(muted ? fuchsia::media::audio::MUTED_GAIN_DB
                                                         : limited.gain_db);
      }
    });
  } else {
    // For inputs, change the gain of all links where it is the source.
    FX_DCHECK(is_input());
    link_matrix_.ForEachDestLink(*this, [&limited](LinkMatrix::LinkHandle link) {
      if (link.object->type() == AudioObject::Type::AudioCapturer) {
        const auto muted = limited.flags & fuchsia::media::AudioGainInfoFlag_Mute;
        link.mixer->bookkeeping().gain.SetSourceGain(muted ? fuchsia::media::audio::MUTED_GAIN_DB
                                                           : limited.gain_db);
      }
    });
  }

  FX_DCHECK(device_settings_ != nullptr);
  if (device_settings_->SetGainInfo(limited, set_flags)) {
    Wakeup();
  }
}

zx_status_t AudioDevice::Init() {
  TRACE_DURATION("audio", "AudioDevice::Init");
  WakeupEvent::ProcessHandler process_handler(
      [weak_output = weak_from_this()](WakeupEvent* event) -> zx_status_t {
        auto output = weak_output.lock();
        if (output) {
          OBTAIN_EXECUTION_DOMAIN_TOKEN(token, &output->mix_domain());
          output->OnWakeup();
        }
        return ZX_OK;
      });

  zx_status_t res = mix_wakeup_.Activate(mix_domain_->dispatcher(), std::move(process_handler));
  if (res != ZX_OK) {
    FX_PLOGS(ERROR, res) << "Failed to activate wakeup event for AudioDevice";
    return res;
  }

  return ZX_OK;
}

void AudioDevice::Cleanup() {
  TRACE_DURATION("audio", "AudioDevice::Cleanup");
  mix_wakeup_.Deactivate();
  // ThrottleOutput devices have no driver, so check for that.
  if (driver_ != nullptr) {
    // Instruct the driver to release all its resources (channels, timer).
    driver_->Cleanup();
  }
  mix_domain_ = nullptr;
}

void AudioDevice::ActivateSelf() {
  TRACE_DURATION("audio", "AudioDevice::ActivateSelf");
  // If we aren't shutting down, tell DeviceManager we are ready for work.
  if (!is_shutting_down()) {
    // Create default settings. The device manager will restore these settings
    // from persistent storage for us when it gets our activation message.
    FX_DCHECK(device_settings_ == nullptr);
    FX_DCHECK(driver() != nullptr);

    HwGainState gain_state = driver()->hw_gain_state();

    // We disregard the device's gain at the time of connection and set it to 0,
    // pending restoration of device_settings.
    gain_state.cur_gain = kDefaultDeviceGain;

    const auto id = driver()->persistent_unique_id();

    device_settings_ = fbl::MakeRefCounted<AudioDeviceSettings>(id, gain_state, is_input());

    // Now poke our manager.
    threading_model().FidlDomain().PostTask(
        [self = shared_from_this()]() { self->device_registry().ActivateDevice(std::move(self)); });
  }
}

void AudioDevice::ShutdownSelf() {
  TRACE_DURATION("audio", "AudioDevice::ShutdownSelf");
  // If we are not already in the process of shutting down, send a message to
  // the main message loop telling it to complete the shutdown process.
  if (!is_shutting_down()) {
    shutting_down_.store(true);

    threading_model().FidlDomain().PostTask(
        [self = shared_from_this()]() { self->device_registry().RemoveDevice(self); });
  }
}

fit::promise<void, zx_status_t> AudioDevice::Startup() {
  TRACE_DURATION("audio", "AudioDevice::Startup");
  fit::bridge<void, zx_status_t> bridge;
  mix_domain_->PostTask(
      [self = shared_from_this(), completer = std::move(bridge.completer)]() mutable {
        OBTAIN_EXECUTION_DOMAIN_TOKEN(token, &self->mix_domain());
        zx_status_t res = self->Init();
        if (res != ZX_OK) {
          self->Cleanup();
          completer.complete_error(res);
          return;
        }
        self->OnWakeup();
        completer.complete_ok();
      });
  return bridge.consumer.promise();
}

fit::promise<void> AudioDevice::Shutdown() {
  TRACE_DURATION("audio", "AudioDevice::Shutdown");
  // The only reason we have this flag is to make sure that Shutdown is idempotent.
  if (shut_down_) {
    return fit::make_ok_promise();
  }
  shut_down_ = true;

  // Give our derived class, and our driver, a chance to clean up resources.
  fit::bridge<void> bridge;
  mix_domain_->PostTask(
      [self = shared_from_this(), completer = std::move(bridge.completer)]() mutable {
        OBTAIN_EXECUTION_DOMAIN_TOKEN(token, &self->mix_domain());
        self->Cleanup();
        completer.complete_ok();
      });
  return bridge.consumer.promise();
}

bool AudioDevice::UpdatePlugState(bool plugged, zx::time plug_time) {
  TRACE_DURATION("audio", "AudioDevice::UpdatePlugState");
  if ((plugged != plugged_) && (plug_time >= plug_time_) && !is_shutting_down()) {
    plugged_ = plugged;
    plug_time_ = plug_time;
    return true;
  }

  return false;
}

const std::shared_ptr<RingBuffer>& AudioDevice::driver_ring_buffer() const {
  return driver_->ring_buffer();
};

TimelineFunction AudioDevice::device_reference_clock_to_ring_pos_bytes() const {
  return driver_->clock_mono_to_ring_pos_bytes();
};

void AudioDevice::GetDeviceInfo(fuchsia::media::AudioDeviceInfo* out_info) const {
  TRACE_DURATION("audio", "AudioDevice::GetDeviceInfo");
  const auto& drv = *driver();
  out_info->name = drv.manufacturer_name() + ' ' + drv.product_name();
  out_info->unique_id = UniqueIdToString(drv.persistent_unique_id());
  out_info->token_id = token();
  out_info->is_input = is_input();
  out_info->is_default = false;

  FX_DCHECK(device_settings_);
  device_settings_->GetGainInfo(&out_info->gain_info);
}

}  // namespace media::audio