src/audio_server.cpp

#include <sys/types.h>
#include <unistd.h>
#include <sys/stat.h>
#include <fcntl.h>

#include <boost/interprocess/managed_shared_memory.hpp>
#include <cstdlib>
#include <iomanip>
#include <mutex>
#include <signal.h>

#define LOG_TAG "audio_server"
#include <cutils/log.h>

#include <grpc/grpc.h>
#include <grpcpp/server.h>
#include <grpcpp/server_builder.h>
#include <grpcpp/server_context.h>
#include <grpcpp/security/server_credentials.h>
#include "audio_if.h"
#include "audio_service.grpc.pb.h"
#include "CircularBuffer.h"

using grpc::Server;
using grpc::ServerBuilder;
using grpc::ServerContext;
using grpc::ServerReader;
using grpc::ServerReaderWriter;
using grpc::ServerWriter;
using grpc::Status;
using audio_service::StatusReturn;
using audio_service::Volume;
using audio_service::Mode;
using audio_service::Mute;
using audio_service::Kv_pairs;
using audio_service::Keys;
using audio_service::Handle;
using audio_service::OpenOutputStream;
using audio_service::Stream;
using audio_service::OpenInputStream;
using audio_service::CreateAudioPatch;
using audio_service::AudioPortConfig;
using audio_service::AudioGainConfig;
using audio_service::AudioPortConfigDeviceExt;
using audio_service::AudioPortConfigMixExt;
using audio_service::AudioPortConfigSessionExt;
using audio_service::StreamSetParameters;
using audio_service::StreamGetParameters;
using audio_service::StreamAudioEffect;
using audio_service::StreamOutSetVolume;
using audio_service::StreamReadWrite;
using audio_service::GetFrameTimestampReturn;
using audio_service::StreamGain;
using google::protobuf::Empty;

using namespace boost::interprocess;
using namespace audio_service;

//#define DEBUG__

#ifdef DEBUG__
#define TRACE_ENTRY() ALOGI("%s enter\n", __func__)
#define TRACE_EXIT() ALOGI("%s exit\n", __func__)
#else
#define TRACE_ENTRY()
#define TRACE_EXIT()
#endif

const int AudioServerShmemSize = 16 * 1024 * 1024;

typedef std::pair<CircularBuffer *, struct audio_stream_out *> streamout_map_t;
typedef std::pair<CircularBuffer *, struct audio_stream_in *> streamin_map_t;

class AudioServiceImpl final : public AudioService::Service
{
  public:
    explicit AudioServiceImpl(managed_shared_memory &shm)
      : shm_(shm) {
        if (audio_hw_load_interface(&dev_) == 0) {
          //ALOGI(__func__, "[AudioServer] Get audio hal interface successfully.\n");
        }
      }

    ~AudioServiceImpl() {
      if (dev_) {
        audio_hw_unload_interface(dev_);
        dev_ = nullptr;
      }
    }

    Status Device_common_close(ServerContext* context, const Empty* empty, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      response->set_ret(dev_->common.close(&dev_->common));
      return Status::OK;
    }

    Status Device_init_check(ServerContext* context, const Empty* empty, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      response->set_ret(dev_->init_check(dev_));
      return Status::OK;
    }

    Status Device_set_voice_volume(ServerContext* context, const Volume* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      response->set_ret(dev_->set_voice_volume(dev_, request->vol()));
      return Status::OK;
    }

    Status Device_set_master_volume(ServerContext* context, const Volume* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      response->set_ret(dev_->set_master_volume(dev_, request->vol()));
      return Status::OK;
    }

    Status Device_get_master_volume(ServerContext* context, const Empty* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      float vol = 0.0;
      response->set_ret(dev_->get_master_volume(dev_, &vol));
      response->set_status_float(vol);
      return Status::OK;
    }

    Status Device_set_mode(ServerContext* context, const Mode* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      response->set_ret(dev_->set_mode(dev_, (audio_mode_t)(request->mode())));
      return Status::OK;
    }

    Status Device_set_mic_mute(ServerContext* context, const Mute* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      response->set_ret(dev_->set_mic_mute(dev_, request->mute()));
      return Status::OK;
    }

    Status Device_get_mic_mute(ServerContext* context, const Empty* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      bool mute = false;
      response->set_ret(dev_->get_mic_mute(dev_, &mute));
      response->set_status_bool(mute);
      return Status::OK;
    }

    Status Device_set_parameters(ServerContext* context, const Kv_pairs* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      response->set_ret(dev_->set_parameters(dev_, request->params().c_str()));
      return Status::OK;
    }

    Status Device_get_parameters(ServerContext* context, const Keys* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      char *param = dev_->get_parameters(dev_, request->keys().c_str());
      response->set_ret(param ? 0 : -1);
      response->set_status_string(std::string(param));

      // param is heap allocated and need free in behalf of client
      free(param);

      return Status::OK;
    }

    Status Device_get_input_buffer_size(ServerContext* context, const AudioConfig* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      struct audio_config config;
      config.sample_rate = request->sample_rate();
      config.channel_mask = request->channel_mask();
      config.format = (audio_format_t)(request->format());
      config.frame_count = request->frame_count();

      response->set_ret(dev_->get_input_buffer_size(dev_, &config));
      return Status::OK;
    }

    Status Device_open_output_stream(ServerContext* context, const OpenOutputStream* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      struct audio_stream_out *stream = nullptr;
      struct audio_config config;
      config.sample_rate = request->config().sample_rate();
      config.channel_mask = request->config().channel_mask();
      config.format = (audio_format_t)(request->config().format());
      config.frame_count = request->config().frame_count();

      streamout_gc_();

      response->set_ret(dev_->open_output_stream(dev_,
                          (audio_io_handle_t)(request->handle()),
                          (audio_devices_t)(request->devices()),
                          (audio_output_flags_t)(request->flags()),
                          &config,
                          &stream,
                          request->address().c_str()));

      if (stream) {
        CircularBuffer * cb = shm_.find<CircularBuffer>(request->name().c_str()).first;
        if (cb == nullptr)
          cb = shm_.construct<CircularBuffer>(request->name().c_str())(shm_, request->size());

        std::lock_guard<std::mutex> lock(map_out_mutex_);
        streamout_map_.insert(
          std::pair<const std::string, streamout_map_t>(request->name(), streamout_map_t(cb, stream)));
      }

      return Status::OK;
    }

    Status Device_close_output_stream(ServerContext* context, const Stream* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      std::map<const std::string, streamout_map_t >::iterator it = streamout_map_.find(request->name());
      if (it == streamout_map_.end()) return Status::CANCELLED;

      dev_->close_output_stream(dev_, it->second.second);

      if (it->second.first) {
        shm_.destroy<CircularBuffer>(request->name().c_str());
      }

      std::lock_guard<std::mutex> lock(map_out_mutex_);
      streamout_map_.erase(it);

      TRACE_EXIT();

      return Status::OK;
    }

    Status Device_open_input_stream(ServerContext* context, const OpenInputStream* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      struct audio_stream_in *stream = nullptr;
      struct audio_config config;
      config.sample_rate = request->config().sample_rate();
      config.channel_mask = request->config().channel_mask();
      config.format = (audio_format_t)(request->config().format());
      config.frame_count = request->config().frame_count();

      streamin_gc_();

      response->set_ret(dev_->open_input_stream(dev_,
                          (audio_io_handle_t)(request->handle()),
                          (audio_devices_t)(request->devices()),
                          &config,
                          &stream,
                          (audio_input_flags_t)(request->flags()),
                          request->address().c_str(),
                          (audio_source_t)(request->source())));

      if (stream) {
        CircularBuffer * cb = shm_.find<CircularBuffer>(request->name().c_str()).first;
        if (cb == nullptr)
          cb = shm_.construct<CircularBuffer>(request->name().c_str())(shm_, request->size());

        std::lock_guard<std::mutex> lock(map_in_mutex_);
        streamin_map_.insert(
          std::pair<const std::string, streamin_map_t>(request->name(), streamin_map_t(cb, stream)));
      }

      return Status::OK;
    }

    Status Device_close_input_stream(ServerContext* context, const Stream* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      std::map<const std::string, streamin_map_t >::iterator it = streamin_map_.find(request->name());
      if (it == streamin_map_.end()) return Status::CANCELLED;

      dev_->close_input_stream(dev_, it->second.second);

      if (it->second.first) {
        shm_.destroy<CircularBuffer>(request->name().c_str());
      }

      std::lock_guard<std::mutex> lock(map_in_mutex_);
      streamin_map_.erase(it);

      return Status::OK;
    }

    Status Device_dump(ServerContext* context, const Empty* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      char *param = dev_->dump(dev_, 0);
      response->set_ret(param ? 0 : -1);
      response->set_status_string(std::string(param));

      // param is heap allocated and need free
      free(param);

      return Status::OK;
    }

    Status Device_set_master_mute(ServerContext* context, const Mute* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      response->set_ret(dev_->set_master_mute(dev_, request->mute()));
      return Status::OK;
    }

    Status Device_get_master_mute(ServerContext* context, const Empty* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      bool mute = false;
      response->set_ret(dev_->get_master_mute(dev_, &mute));
      response->set_status_bool(mute);
      return Status::OK;
    }

    Status Device_create_audio_patch(ServerContext* context, const CreateAudioPatch* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      struct audio_port_config *sources, *sinks;
      unsigned int num_sources = request->sources_size();
      unsigned int num_sinks = request->sinks_size();

      struct audio_port_config *configs = new struct audio_port_config[num_sources + num_sinks];

      streamout_gc_();
      streamin_gc_();

      for (int i = 0; i < num_sources + num_sinks; i++) {
        const AudioPortConfig &config = (i < num_sources) ?
          request->sources(i) : request->sinks(i - num_sources);
        configs[i].id = config.id();
        configs[i].role = (audio_port_role_t)config.role();
        configs[i].type = (audio_port_type_t)config.type();
        configs[i].config_mask = config.config_mask();
        configs[i].sample_rate = config.sample_rate();
        configs[i].channel_mask = config.channel_mask();
        configs[i].format = (audio_format_t)config.format();

        // gain
        configs[i].gain.index = config.gain().index();
        configs[i].gain.mode = (audio_gain_mode_t)config.gain().mode();
        configs[i].gain.channel_mask = (audio_channel_mask_t)config.gain().channel_mask();
        for (int j = 0; j < config.gain().values_size(); j++)
          configs[i].gain.values[j] = config.gain().values(j);
        configs[i].gain.ramp_duration_ms = config.gain().ramp_duration_ms();

        if (configs[i].type == AUDIO_PORT_TYPE_DEVICE) {
          // AudioPortConfigDeviceExt
          configs[i].ext.device.hw_module = (audio_module_handle_t)config.device().hw_module();
          configs[i].ext.device.type = (audio_devices_t)config.device().type();
          strncpy(configs[i].ext.device.address, config.device().address().c_str(), AUDIO_DEVICE_MAX_ADDRESS_LEN);
        } else if (configs[i].type == AUDIO_PORT_TYPE_MIX) {
          // AudioPortConfigMixExt
          configs[i].ext.mix.hw_module = (audio_module_handle_t)config.mix().hw_module();
          configs[i].ext.mix.handle = (audio_io_handle_t)config.mix().handle();
          configs[i].ext.mix.usecase.stream = (audio_stream_type_t)config.mix().stream_source();
        } else if (configs[i].type == AUDIO_PORT_TYPE_SESSION) {
          // AudioPortConfigSessionExt
          configs[i].ext.session.session = (audio_session_t)config.session().session();
        }
      }

      audio_patch_handle_t handle = (audio_patch_handle_t)(-1);
      response->set_ret(dev_->create_audio_patch(dev_, num_sources,
                                                  configs, num_sinks, &configs[num_sources], &handle));
      response->set_status_32((uint32_t)handle);

      delete [] configs;

      return Status::OK;
    }

    Status Device_release_audio_patch(ServerContext* context, const Handle* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      audio_patch_handle_t handle = (audio_patch_handle_t)(request->handle());
      response->set_ret(dev_->release_audio_patch(dev_, handle));
      return Status::OK;
    }

    Status Device_set_audio_port_config(ServerContext* context, const AudioPortConfig* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      struct audio_port_config config;

      config.id = request->id();
      config.role = (audio_port_role_t)request->role();
      config.type = (audio_port_type_t)request->type();
      config.config_mask = request->config_mask();
      config.sample_rate = request->sample_rate();
      config.channel_mask = request->channel_mask();
      config.format = (audio_format_t)request->format();

      // gain
      config.gain.index = request->gain().index();
      config.gain.mode = (audio_gain_mode_t)request->gain().mode();
      config.gain.channel_mask = (audio_channel_mask_t)request->gain().channel_mask();
      for (int j = 0; j < request->gain().values_size(); j++)
        config.gain.values[j] = request->gain().values(j);
      config.gain.ramp_duration_ms = request->gain().ramp_duration_ms();

      if (config.type == AUDIO_PORT_TYPE_DEVICE) {
        // AudioPortConfigDeviceExt
        config.ext.device.hw_module = (audio_module_handle_t)request->device().hw_module();
        config.ext.device.type = (audio_devices_t)request->device().type();
        strncpy(config.ext.device.address, request->device().address().c_str(), AUDIO_DEVICE_MAX_ADDRESS_LEN);
      } else if (config.type == AUDIO_PORT_TYPE_MIX) {
        // AudioPortConfigMixExt
        config.ext.mix.hw_module = (audio_module_handle_t)request->mix().hw_module();
        config.ext.mix.handle = (audio_io_handle_t)request->mix().handle();
        config.ext.mix.usecase.stream = (audio_stream_type_t)request->mix().stream_source();
      } else if (config.type == AUDIO_PORT_TYPE_SESSION) {
        // AudioPortConfigSessionExt
        config.ext.session.session = (audio_session_t)request->session().session();
      }

      response->set_ret(dev_->set_audio_port_config(dev_, &config));
      return Status::OK;
    }

    Status Stream_get_sample_rate(ServerContext* context, const Stream* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      struct audio_stream *stream = find_stream(request->name(), streamout_map_, streamin_map_);
      if (stream == nullptr) return Status::CANCELLED;

      response->set_ret(stream->get_sample_rate(stream));
      return Status::OK;
    }

    Status Stream_get_buffer_size(ServerContext* context, const Stream* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      struct audio_stream *stream = find_stream(request->name(), streamout_map_, streamin_map_);
      if (stream == nullptr) return Status::CANCELLED;

      response->set_ret(stream->get_buffer_size(stream));
      return Status::OK;
    }

    Status Stream_get_channels(ServerContext* context, const Stream* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      struct audio_stream *stream = find_stream(request->name(), streamout_map_, streamin_map_);
      if (stream == nullptr) return Status::CANCELLED;

      response->set_ret((uint32_t)stream->get_channels(stream));
      return Status::OK;
    }

    Status Stream_get_format(ServerContext* context, const Stream* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      struct audio_stream *stream = find_stream(request->name(), streamout_map_, streamin_map_);
      if (stream == nullptr) return Status::CANCELLED;

      response->set_ret((uint32_t)stream->get_format(stream));
      return Status::OK;
    }

    Status Stream_standby(ServerContext* context, const Stream* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      struct audio_stream *stream = find_stream(request->name(), streamout_map_, streamin_map_);
      if (stream == nullptr) return Status::CANCELLED;

      response->set_ret((uint32_t)stream->standby(stream));
      return Status::OK;
    }

    Status Stream_get_device(ServerContext* context, const Stream* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      struct audio_stream *stream = find_stream(request->name(), streamout_map_, streamin_map_);
      if (stream == nullptr) return Status::CANCELLED;

      response->set_ret((uint32_t)stream->get_device(stream));
      return Status::OK;
    }

    Status Stream_set_parameters(ServerContext* context, const StreamSetParameters* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      struct audio_stream *stream = find_stream(request->name(), streamout_map_, streamin_map_);
      if (stream == nullptr) return Status::CANCELLED;

      const char *kv_pairs = request->kv_pairs().c_str();
      response->set_ret(stream->set_parameters(stream, kv_pairs));
      return Status::OK;
    }

    Status Stream_get_parameters(ServerContext* context, const StreamGetParameters* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      struct audio_stream *stream = find_stream(request->name(), streamout_map_, streamin_map_);
      if (stream == nullptr) return Status::CANCELLED;

      char *param = stream->get_parameters(stream, request->keys().c_str());
      response->set_ret(param ? 0 : -1);
      response->set_status_string(std::string(param));

      // param is heap allocated and need free in behalf of client
      free(param);

      return Status::OK;
    }

    Status StreamOut_get_latency(ServerContext* context, const Stream* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      struct audio_stream_out *stream = find_streamout(request->name(), streamout_map_);
      if (stream == nullptr) return Status::CANCELLED;

      response->set_ret(stream->get_latency(stream));
      return Status::OK;
    }

    Status StreamOut_set_volume(ServerContext* context, const StreamOutSetVolume* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      struct audio_stream_out *stream = find_streamout(request->name(), streamout_map_);
      if (stream == nullptr) return Status::CANCELLED;

      response->set_ret(stream->set_volume(stream, request->left(), request->right()));
      return Status::OK;
    }

    Status StreamOut_write(ServerContext* context, const StreamReadWrite* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      struct audio_stream_out *stream = find_streamout(request->name(), streamout_map_);
      if (stream == nullptr) return Status::CANCELLED;

      CircularBuffer *cb = shm_.find<CircularBuffer>(request->name().c_str()).first;
      response->set_ret(stream->write(stream, cb->start_ptr(shm_), request->size()));
      return Status::OK;
    }

    Status StreamOut_get_render_position(ServerContext* context, const Stream* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      struct audio_stream_out *stream = find_streamout(request->name(), streamout_map_);
      if (stream == nullptr) return Status::CANCELLED;

      uint32_t dsp_frames = 0;
      response->set_ret(stream->get_render_position(stream, &dsp_frames));
      response->set_status_32(dsp_frames);
      return Status::OK;
    }

    Status StreamOut_get_next_write_timestamp(ServerContext* context, const Stream* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      struct audio_stream_out *stream = find_streamout(request->name(), streamout_map_);
      if (stream == nullptr) return Status::CANCELLED;

      int64_t timestamp = 0;
      response->set_ret(stream->get_next_write_timestamp(stream, &timestamp));
      response->set_status_64(timestamp);
      return Status::OK;
    }

    Status StreamOut_pause(ServerContext* context, const Stream* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      struct audio_stream_out *stream = find_streamout(request->name(), streamout_map_);
      if (stream == nullptr) return Status::CANCELLED;

      response->set_ret(stream->pause(stream));
      return Status::OK;
    }

    Status StreamOut_resume(ServerContext* context, const Stream* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      struct audio_stream_out *stream = find_streamout(request->name(), streamout_map_);
      if (stream == nullptr) return Status::CANCELLED;

      response->set_ret(stream->resume(stream));
      return Status::OK;
    }

    Status StreamOut_flush(ServerContext* context, const Stream* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      struct audio_stream_out *stream = find_streamout(request->name(), streamout_map_);
      if (stream == nullptr) return Status::CANCELLED;

      response->set_ret(stream->flush(stream));
      return Status::OK;
    }

    Status StreamOut_get_presentation_position(ServerContext* context, const Stream* request, GetFrameTimestampReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      struct audio_stream_out *stream = find_streamout(request->name(), streamout_map_);
      if (stream == nullptr) return Status::CANCELLED;

      uint64_t frames = 0;
      struct timespec timestamp;
      response->set_ret(stream->get_presentation_position(stream, &frames, &timestamp));
      response->set_frames(frames);
      response->mutable_timestamp()->set_seconds((int64_t)timestamp.tv_sec);
      response->mutable_timestamp()->set_nanos(timestamp.tv_nsec);
      return Status::OK;
    }

    Status StreamIn_set_gain(ServerContext* context, const StreamGain* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      struct audio_stream_in *stream = find_streamin(request->name(), streamin_map_);
      if (stream == nullptr) return Status::CANCELLED;

      response->set_ret(stream->set_gain(stream, request->gain()));
      return Status::OK;
    }

    Status StreamIn_read(ServerContext* context, const StreamReadWrite* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      struct audio_stream_in *stream = find_streamin(request->name(), streamin_map_);
      if (stream == nullptr) return Status::CANCELLED;

      CircularBuffer *cb = shm_.find<CircularBuffer>(request->name().c_str()).first;
      response->set_ret(stream->read(stream, cb->start_ptr(shm_), std::min(request->size(), cb->capacity())));
      return Status::OK;
    }

    Status StreamIn_get_input_frames_lost(ServerContext* context, const Stream* request, StatusReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      struct audio_stream_in *stream = find_streamin(request->name(), streamin_map_);
      if (stream == nullptr) return Status::CANCELLED;

      response->set_ret(stream->get_input_frames_lost(stream));
      return Status::OK;
    }

    Status StreamIn_get_capture_position(ServerContext* context, const Stream* request, GetCapturePositionReturn* response) {
      TRACE_ENTRY();
      if (!dev_) return Status::CANCELLED;

      struct audio_stream_in *stream = find_streamin(request->name(), streamin_map_);
      if (stream == nullptr) return Status::CANCELLED;

      int64_t frames = 0;
      int64_t time = 0;
      response->set_ret(stream->get_capture_position(stream, &frames, &time));
      response->set_frames(frames);
      response->set_time(time);

      return Status::OK;
    }

    Status Service_ping(ServerContext* context, const Empty* empty, StatusReturn* response) {
      TRACE_ENTRY();
      response->set_status_32(0);
      return Status::OK;
    }

  private:
    void streamout_gc_()
    {
      std::lock_guard<std::mutex> lock_out(map_out_mutex_);
      for (std::map<const std::string, streamout_map_t >::iterator it = streamout_map_.begin(); it != streamout_map_.end(); ) {
          int pid, seq;
          bool need_close = false;

          if (sscanf(it->first.c_str(), "%d-%d", &pid, &seq) == 2) {
            printf("!!!! found pid = %d\n", pid);
            // Garbage collect streams when PID does not exists.
            // It happens when client side crashed, or the client
            // side does not have the right sequence to close opened streams.
            if ((kill(pid, 0) == -1) && (errno == ESRCH)) {
              need_close = true;
            }
          }
          if (need_close) {
            dev_->close_output_stream(dev_, it->second.second);
            if (it->second.first) {
              shm_.destroy<CircularBuffer>(it->first.c_str());
            }
            streamout_map_.erase(it++);
          } else {
            ++it;
          }
      }
    }

    void streamin_gc_()
    {
      std::lock_guard<std::mutex> lock_out(map_in_mutex_);
      for (std::map<const std::string, streamin_map_t >::iterator it = streamin_map_.begin(); it != streamin_map_.end(); ) {
          int pid, seq;
          bool need_close = false;

          if (sscanf(it->first.c_str(), "%d-%d", &pid, &seq) == 2) {
            // Garbage collect streams when PID does not exists.
            // It happens when client side crashed, or the client
            // side does not have the right sequence to close opened streams.
            if (kill(pid, 0) == ESRCH) {
              need_close = true;
            }
          }
          if (need_close) {
            dev_->close_input_stream(dev_, it->second.second);
            streamin_map_.erase(it++);
          } else {
            ++it;
          }
      }
    }

    struct audio_stream *find_stream(std::string name,
                                     std::map<const std::string, streamout_map_t> &map_out,
                                     std::map<const std::string, streamin_map_t> &map_in)
    {
      std::lock_guard<std::mutex> lock_out(map_out_mutex_);
      std::map<const std::string, streamout_map_t >::iterator it_out = map_out.find(name);
      if (it_out != map_out.end()) {
        return &it_out->second.second->common;
      }

      std::lock_guard<std::mutex> lock_in(map_in_mutex_);
      std::map<const std::string, streamin_map_t >::iterator it_in = map_in.find(name);
      if (it_in != map_in.end()) {
        return &it_in->second.second->common;
      }

      return nullptr;
    }

    struct audio_stream_out *find_streamout(std::string name,
                                            std::map<const std::string, streamout_map_t> &map_out)
    {
      std::lock_guard<std::mutex> lock(map_out_mutex_);
      std::map<const std::string, streamout_map_t >::iterator it = map_out.find(name);
      if (it != map_out.end()) {
        return it->second.second;
      }

      return nullptr;
    }

    struct audio_stream_in *find_streamin(std::string name,
                                          std::map<const std::string, streamin_map_t> &map_in)
    {
      std::lock_guard<std::mutex> lock(map_in_mutex_);
      std::map<const std::string, streamin_map_t >::iterator it = map_in.find(name);
      if (it != map_in.end()) {
        return it->second.second;
      }

      return nullptr;
    }

    managed_shared_memory &shm_;

    /* audio hal interface */
    struct audio_hw_device *dev_;
    static std::mutex map_in_mutex_;
    static std::mutex map_out_mutex_;
    std::map<const std::string, streamout_map_t > streamout_map_;
    std::map<const std::string, streamin_map_t > streamin_map_;
};

std::mutex AudioServiceImpl::map_out_mutex_;
std::mutex AudioServiceImpl::map_in_mutex_;

void RunServer(managed_shared_memory& shm)
{
  const char *url = std::getenv("AUDIO_SERVER_SOCKET");
  std::string server_address("unix:///opt/audio_socket");
  AudioServiceImpl service(shm);
  if (url) {
      server_address = url;
  }
  ServerBuilder builder;
  builder.AddListeningPort(server_address, grpc::InsecureServerCredentials());
  builder.RegisterService(&service);
  std::unique_ptr<Server> server(builder.BuildAndStart());
  std::cout << "[AudioServer] listening on " << server_address << std::endl;
  server->Wait();
}

static int daemonize()
{
  int fd_pid;
  const char pidfile[] = "/var/run/audio_server.pid";
  char pid[10];

  fd_pid = open(pidfile, O_RDWR|O_CREAT, 0600);
  if (fd_pid == -1) {
    fprintf(stderr, "Unable to open PID lock file\n");
    return -1;
  }

  if (lockf(fd_pid, F_TLOCK, 0) == -1) {
    fprintf(stderr, "Unable to lock PID file, daemon is existing.\n");
    return -2;
  }

  snprintf(pid, sizeof(pid), "%d", getpid());
  write(fd_pid, pid, strlen(pid));

  return 0;
}

int main(int argc, char** argv)
{
  int r = daemonize();
  if (r < 0)
    return r;

  shared_memory_object::remove("AudioServiceShmem");
  managed_shared_memory shm{open_or_create, "AudioServiceShmem", AudioServerShmemSize};

  RunServer(shm);
  return 0;
}