audio/device_port_sink.cpp - device/generic/goldfish - Git at Google

 /*
  * Copyright (C) 2020 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #include PATH(APM_XSD_ENUMS_H_FILENAME)
 #include <android-base/properties.h>
 #include <chrono>
 #include <thread>
 #include <log/log.h>
 #include <utils/Mutex.h>
 #include <utils/Timers.h>
 #include <utils/ThreadDefs.h>
 #include "device_port_sink.h"
 #include "talsa.h"
 #include "audio_ops.h"
 #include "ring_buffer.h"
 #include "util.h"
 #include "debug.h"

 using ::android::base::GetBoolProperty;

 namespace xsd {
 using namespace ::android::audio::policy::configuration::CPP_VERSION;
 }

 namespace android {
 namespace hardware {
 namespace audio {
 namespace CPP_VERSION {
 namespace implementation {

 namespace {

 constexpr int kMaxJitterUs = 3000;  // Enforced by CTS, should be <= 6ms

 struct TinyalsaSink : public DevicePortSink {
     TinyalsaSink(unsigned pcmCard, unsigned pcmDevice,
                  const AudioConfig &cfg,
                  uint64_t &frames)
             : mStartNs(systemTime(SYSTEM_TIME_MONOTONIC))
             , mSampleRateHz(cfg.base.sampleRateHz)
             , mFrameSize(util::countChannels(cfg.base.channelMask) * sizeof(int16_t))
             , mWriteSizeFrames(cfg.frameCount)
             , mInitialFrames(frames)
             , mFrames(frames)
             , mRingBuffer(mFrameSize * cfg.frameCount * 3)
             , mMixer(pcmCard)
             , mPcm(talsa::pcmOpen(pcmCard, pcmDevice,
                                   util::countChannels(cfg.base.channelMask),
                                   cfg.base.sampleRateHz,
                                   cfg.frameCount,
                                   true /* isOut */)) {
         if (mPcm) {
             LOG_ALWAYS_FATAL_IF(!talsa::pcmPrepare(mPcm.get()));
             mConsumeThread = std::thread(&TinyalsaSink::consumeThread, this);
         } else {
             mConsumeThread = std::thread([](){});
         }
     }

     ~TinyalsaSink() {
         mConsumeThreadRunning = false;
         mConsumeThread.join();
     }

     static int getLatencyMs(const AudioConfig &cfg) {
         constexpr size_t inMs = 1000;
         const talsa::PcmPeriodSettings periodSettings =
             talsa::pcmGetPcmPeriodSettings();
         const size_t numerator = periodSettings.periodSizeMultiplier * cfg.frameCount;
         const size_t denominator = periodSettings.periodCount * cfg.base.sampleRateHz / inMs;

         // integer division with rounding
         return (numerator + (denominator >> 1)) / denominator + talsa::pcmGetHostLatencyMs();
     }

     Result getPresentationPosition(uint64_t &frames, TimeSpec &ts) override {
         const AutoMutex lock(mFrameCountersMutex);

         nsecs_t nowNs = systemTime(SYSTEM_TIME_MONOTONIC);
         const uint64_t nowFrames = getPresentationFramesLocked(nowNs);
         auto presentedFrames = nowFrames - mMissedFrames;
         if (presentedFrames > mReceivedFrames) {
           // There is another underrun that is not yet accounted for in mMissedFrames
           auto delta = presentedFrames - mReceivedFrames;
           presentedFrames -= delta;
           // The last frame was presented some time ago, reflect that in the result
           nowNs -= delta * 1000000000 / mSampleRateHz;
         }
         mFrames = presentedFrames + mInitialFrames;

         frames = mFrames;
         ts = util::nsecs2TimeSpec(nowNs);
         return Result::OK;
     }

     uint64_t getPresentationFramesLocked(const nsecs_t nowNs) const {
         return uint64_t(mSampleRateHz) * ns2us(nowNs - mStartNs) / 1000000;
     }

     size_t calcAvailableFramesNowLocked() {
         const nsecs_t nowNs = systemTime(SYSTEM_TIME_MONOTONIC);
         auto presentationFrames = getPresentationFramesLocked(nowNs);
         if (mReceivedFrames + mMissedFrames < presentationFrames) {
             // There has been an underrun
             mMissedFrames = presentationFrames - mReceivedFrames;
         }
         size_t pendingFrames = mReceivedFrames + mMissedFrames - presentationFrames;
         return mRingBuffer.capacity() / mFrameSize - pendingFrames;
     }

     size_t calcWaitFramesNowLocked(const size_t requestedFrames) {
         const size_t availableFrames = calcAvailableFramesNowLocked();
         return (requestedFrames > availableFrames)
             ? (requestedFrames - availableFrames) : 0;
     }

     size_t write(float volume, size_t bytesToWrite, IReader &reader) {
         const AutoMutex lock(mFrameCountersMutex);

         size_t framesLost = 0;
         const size_t waitFrames = calcWaitFramesNowLocked(bytesToWrite / mFrameSize);
         const auto blockUntil =
             std::chrono::high_resolution_clock::now() +
                 + std::chrono::microseconds(waitFrames * 1000000 / mSampleRateHz);

         while (bytesToWrite > 0) {
             if (mRingBuffer.waitForProduceAvailable(blockUntil
                     + std::chrono::microseconds(kMaxJitterUs))) {
                 auto produceChunk = mRingBuffer.getProduceChunk();
                 if (produceChunk.size >= bytesToWrite) {
                     // Since the ring buffer has more bytes free than we need,
                     // make sure we are not too early here: tinyalsa is jittery,
                     // we don't want to go faster than SYSTEM_TIME_MONOTONIC
                     std::this_thread::sleep_until(blockUntil);
                 }

                 const size_t szFrames =
                     std::min(produceChunk.size, bytesToWrite) / mFrameSize;
                 const size_t szBytes = szFrames * mFrameSize;
                 LOG_ALWAYS_FATAL_IF(reader(produceChunk.data, szBytes) < szBytes);

                 aops::multiplyByVolume(volume,
                                        static_cast<int16_t *>(produceChunk.data),
                                        szBytes / sizeof(int16_t));

                 LOG_ALWAYS_FATAL_IF(mRingBuffer.produce(szBytes) < szBytes);
                 mReceivedFrames += szFrames;
                 bytesToWrite -= szBytes;
             } else {
                 ALOGV("TinyalsaSink::%s:%d pcm_write was late reading "
                       "frames, dropping %zu us of audio",
                       __func__, __LINE__,
                       size_t(1000000 * bytesToWrite / mFrameSize / mSampleRateHz));

                 // drop old audio to make room for new
                 const size_t bytesLost = mRingBuffer.makeRoomForProduce(bytesToWrite);
                 framesLost += bytesLost / mFrameSize;

                 while (bytesToWrite > 0) {
                     auto produceChunk = mRingBuffer.getProduceChunk();
                     const size_t szFrames =
                         std::min(produceChunk.size, bytesToWrite) / mFrameSize;
                     const size_t szBytes = szFrames * mFrameSize;
                     LOG_ALWAYS_FATAL_IF(reader(produceChunk.data, szBytes) < szBytes);

                     aops::multiplyByVolume(volume,
                                            static_cast<int16_t *>(produceChunk.data),
                                            szBytes / sizeof(int16_t));

                     LOG_ALWAYS_FATAL_IF(mRingBuffer.produce(szBytes) < szBytes);
                     mReceivedFrames += szFrames;
                     bytesToWrite -= szBytes;
                 }
                 break;
             }
         }

         return framesLost;
     }

     void consumeThread() {
         util::setThreadPriority(PRIORITY_URGENT_AUDIO);
         std::vector<uint8_t> writeBuffer(mWriteSizeFrames * mFrameSize);

         while (mConsumeThreadRunning) {
             if (mRingBuffer.waitForConsumeAvailable(
                     std::chrono::high_resolution_clock::now()
                     + std::chrono::microseconds(100000))) {
                 size_t szBytes;
                 {
                     auto chunk = mRingBuffer.getConsumeChunk();
                     szBytes = std::min(writeBuffer.size(), chunk.size);
                     // We have to memcpy because the consumer holds the lock
                     // into RingBuffer and pcm_write takes too long to hold
                     // this lock.
                     memcpy(writeBuffer.data(), chunk.data, szBytes);
                     LOG_ALWAYS_FATAL_IF(mRingBuffer.consume(chunk, szBytes) < szBytes);
                 }

                 talsa::pcmWrite(mPcm.get(), writeBuffer.data(), szBytes);
             }
         }
     }

     static std::unique_ptr<TinyalsaSink> create(unsigned pcmCard,
                                                 unsigned pcmDevice,
                                                 const AudioConfig &cfg,
                                                 size_t readerBufferSizeHint,
                                                 uint64_t &frames) {
         (void)readerBufferSizeHint;
         auto sink = std::make_unique<TinyalsaSink>(pcmCard, pcmDevice,
                                                    cfg, frames);
         if (sink->mMixer && sink->mPcm) {
             return sink;
         } else {
             return FAILURE(nullptr);
         }
     }

 private:
     const nsecs_t mStartNs;
     const unsigned mSampleRateHz;
     const unsigned mFrameSize;
     const unsigned mWriteSizeFrames;
     const uint64_t mInitialFrames;
     uint64_t &mFrames GUARDED_BY(mFrameCountersMutex);
     uint64_t mMissedFrames GUARDED_BY(mFrameCountersMutex) = 0;
     uint64_t mReceivedFrames GUARDED_BY(mFrameCountersMutex) = 0;
     RingBuffer mRingBuffer;
     talsa::Mixer mMixer;
     talsa::PcmPtr mPcm;
     std::thread mConsumeThread;
     std::atomic<bool> mConsumeThreadRunning = true;
     mutable Mutex mFrameCountersMutex;
 };

 struct NullSink : public DevicePortSink {
     NullSink(const AudioConfig &cfg, uint64_t &frames)
             : mStartNs(systemTime(SYSTEM_TIME_MONOTONIC))
             , mSampleRateHz(cfg.base.sampleRateHz)
             , mFrameSize(util::countChannels(cfg.base.channelMask) * sizeof(int16_t))
             , mInitialFrames(frames)
             , mFrames(frames) {}

     static int getLatencyMs(const AudioConfig &) {
         return 1;
     }

     Result getPresentationPosition(uint64_t &frames, TimeSpec &ts) override {
         const AutoMutex lock(mFrameCountersMutex);

         nsecs_t nowNs = systemTime(SYSTEM_TIME_MONOTONIC);
         const uint64_t nowFrames = getPresentationFramesLocked(nowNs);
         auto presentedFrames = nowFrames - mMissedFrames;
         if (presentedFrames > mReceivedFrames) {
           // There is another underrun that is not yet accounted for in mMissedFrames
           auto delta = presentedFrames - mReceivedFrames;
           presentedFrames -= delta;
           // The last frame was presented some time ago, reflect that in the result
           nowNs -= delta * 1000000000 / mSampleRateHz;
         }
         mFrames = presentedFrames + mInitialFrames;

         frames = mFrames;
         ts = util::nsecs2TimeSpec(nowNs);
         return Result::OK;
     }

     uint64_t getPresentationFramesLocked(const nsecs_t nowNs) const {
         return uint64_t(mSampleRateHz) * ns2us(nowNs - mStartNs) / 1000000;
     }

     size_t calcAvailableFramesNowLocked() {
         const nsecs_t nowNs = systemTime(SYSTEM_TIME_MONOTONIC);
         auto presentationFrames = getPresentationFramesLocked(nowNs);
         if (mReceivedFrames + mMissedFrames < presentationFrames) {
             // There has been an underrun
             mMissedFrames = presentationFrames - mReceivedFrames;
         }
         size_t pendingFrames = mReceivedFrames + mMissedFrames - presentationFrames;
         return sizeof(mWriteBuffer) / mFrameSize - pendingFrames;
     }

     size_t calcWaitFramesNowLocked(const size_t requestedFrames) {
         const size_t availableFrames = calcAvailableFramesNowLocked();
         return (requestedFrames > availableFrames)
             ? (requestedFrames - availableFrames) : 0;
     }

     size_t write(float volume, size_t bytesToWrite, IReader &reader) override {
         (void)volume;
         const AutoMutex lock(mFrameCountersMutex);

         const size_t waitFrames = calcWaitFramesNowLocked(bytesToWrite / mFrameSize);
         const auto blockUntil =
             std::chrono::high_resolution_clock::now() +
                 + std::chrono::microseconds(waitFrames * 1000000 / mSampleRateHz);
         std::this_thread::sleep_until(blockUntil);

         while (bytesToWrite > 0) {
             size_t chunkSize =
                 std::min(bytesToWrite, sizeof(mWriteBuffer)) / mFrameSize * mFrameSize;
             chunkSize = reader(mWriteBuffer, chunkSize);
             if (chunkSize > 0) {
                 mReceivedFrames += chunkSize / mFrameSize;
                 bytesToWrite -= chunkSize;
             } else {
                 break; // reader failed
             }
         }

         return 0;
     }

     static std::unique_ptr<NullSink> create(const AudioConfig &cfg,
                                             size_t readerBufferSizeHint,
                                             uint64_t &frames) {
         (void)readerBufferSizeHint;
         return std::make_unique<NullSink>(cfg, frames);
     }

 private:
     const nsecs_t mStartNs;
     const unsigned mSampleRateHz;
     const unsigned mFrameSize;
     const uint64_t mInitialFrames;
     uint64_t &mFrames GUARDED_BY(mFrameCountersMutex);
     uint64_t mMissedFrames GUARDED_BY(mFrameCountersMutex) = 0;
     uint64_t mReceivedFrames GUARDED_BY(mFrameCountersMutex) = 0;
     char mWriteBuffer[1024];
     mutable Mutex mFrameCountersMutex;
 };

 }  // namespace

 std::unique_ptr<DevicePortSink>
 DevicePortSink::create(size_t readerBufferSizeHint,
                        const DeviceAddress &address,
                        const AudioConfig &cfg,
                        const hidl_vec<AudioInOutFlag> &flags,
                        uint64_t &frames) {
     (void)flags;

     if (xsd::stringToAudioFormat(cfg.base.format) != xsd::AudioFormat::AUDIO_FORMAT_PCM_16_BIT) {
         ALOGE("%s:%d, unexpected format: '%s'", __func__, __LINE__, cfg.base.format.c_str());
         return FAILURE(nullptr);
     }

     if (GetBoolProperty("ro.boot.audio.tinyalsa.ignore_output", false)) {
         goto nullsink;
     }

     switch (xsd::stringToAudioDevice(address.deviceType)) {
     case xsd::AudioDevice::AUDIO_DEVICE_OUT_DEFAULT:
     case xsd::AudioDevice::AUDIO_DEVICE_OUT_SPEAKER:
         {
             auto sinkptr = TinyalsaSink::create(talsa::kPcmCard, talsa::kPcmDevice,
                                                 cfg, readerBufferSizeHint, frames);
             if (sinkptr != nullptr) {
                 return sinkptr;
             } else {
                 ALOGW("%s:%d failed to create alsa sink for '%s'; creating NullSink instead.",
                       __func__, __LINE__, address.deviceType.c_str());
             }
         }
         break;

     case xsd::AudioDevice::AUDIO_DEVICE_OUT_TELEPHONY_TX:
     case xsd::AudioDevice::AUDIO_DEVICE_OUT_BUS:
         ALOGW("%s:%d creating NullSink for '%s'.", __func__, __LINE__, address.deviceType.c_str());
         break;

     default:
         ALOGW("%s:%d unsupported device: '%s', creating NullSink", __func__, __LINE__, address.deviceType.c_str());
         break;
     }

 nullsink:
     return NullSink::create(cfg, readerBufferSizeHint, frames);
 }

 int DevicePortSink::getLatencyMs(const DeviceAddress &address, const AudioConfig &cfg) {
     switch (xsd::stringToAudioDevice(address.deviceType)) {
     default:
         ALOGW("%s:%d unsupported device: '%s'", __func__, __LINE__, address.deviceType.c_str());
         return FAILURE(-1);

     case xsd::AudioDevice::AUDIO_DEVICE_OUT_DEFAULT:
     case xsd::AudioDevice::AUDIO_DEVICE_OUT_SPEAKER:
         return TinyalsaSink::getLatencyMs(cfg);

     case xsd::AudioDevice::AUDIO_DEVICE_OUT_TELEPHONY_TX:
     case xsd::AudioDevice::AUDIO_DEVICE_OUT_BUS:
         return NullSink::getLatencyMs(cfg);
     }
 }

 bool DevicePortSink::validateDeviceAddress(const DeviceAddress& address) {
     switch (xsd::stringToAudioDevice(address.deviceType)) {
     default:
         ALOGW("%s:%d unsupported device: '%s'", __func__, __LINE__, address.deviceType.c_str());
         return FAILURE(false);

     case xsd::AudioDevice::AUDIO_DEVICE_OUT_DEFAULT:
     case xsd::AudioDevice::AUDIO_DEVICE_OUT_SPEAKER:
     case xsd::AudioDevice::AUDIO_DEVICE_OUT_TELEPHONY_TX:
     case xsd::AudioDevice::AUDIO_DEVICE_OUT_BUS:
         break;
     }

     return true;
 }

 }  // namespace implementation
 }  // namespace CPP_VERSION
 }  // namespace audio
 }  // namespace hardware
 }  // namespace android
	/*
	* Copyright (C) 2020 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#include PATH(APM_XSD_ENUMS_H_FILENAME)
	#include <android-base/properties.h>
	#include <chrono>
	#include <thread>
	#include <log/log.h>
	#include <utils/Mutex.h>
	#include <utils/Timers.h>
	#include <utils/ThreadDefs.h>
	#include "device_port_sink.h"
	#include "talsa.h"
	#include "audio_ops.h"
	#include "ring_buffer.h"
	#include "util.h"
	#include "debug.h"

	using ::android::base::GetBoolProperty;

	namespace xsd {
	using namespace ::android::audio::policy::configuration::CPP_VERSION;
	}

	namespace android {
	namespace hardware {
	namespace audio {
	namespace CPP_VERSION {
	namespace implementation {

	namespace {

	constexpr int kMaxJitterUs = 3000; // Enforced by CTS, should be <= 6ms

	struct TinyalsaSink : public DevicePortSink {
	TinyalsaSink(unsigned pcmCard, unsigned pcmDevice,
	const AudioConfig &cfg,
	uint64_t &frames)
	: mStartNs(systemTime(SYSTEM_TIME_MONOTONIC))
	, mSampleRateHz(cfg.base.sampleRateHz)
	, mFrameSize(util::countChannels(cfg.base.channelMask) * sizeof(int16_t))
	, mWriteSizeFrames(cfg.frameCount)
	, mInitialFrames(frames)
	, mFrames(frames)
	, mRingBuffer(mFrameSize * cfg.frameCount * 3)
	, mMixer(pcmCard)
	, mPcm(talsa::pcmOpen(pcmCard, pcmDevice,
	util::countChannels(cfg.base.channelMask),
	cfg.base.sampleRateHz,
	cfg.frameCount,
	true /* isOut */)) {
	if (mPcm) {
	LOG_ALWAYS_FATAL_IF(!talsa::pcmPrepare(mPcm.get()));
	mConsumeThread = std::thread(&TinyalsaSink::consumeThread, this);
	} else {
	mConsumeThread = std::thread([](){});
	}
	}

	~TinyalsaSink() {
	mConsumeThreadRunning = false;
	mConsumeThread.join();
	}

	static int getLatencyMs(const AudioConfig &cfg) {
	constexpr size_t inMs = 1000;
	const talsa::PcmPeriodSettings periodSettings =
	talsa::pcmGetPcmPeriodSettings();
	const size_t numerator = periodSettings.periodSizeMultiplier * cfg.frameCount;
	const size_t denominator = periodSettings.periodCount * cfg.base.sampleRateHz / inMs;

	// integer division with rounding
	return (numerator + (denominator >> 1)) / denominator + talsa::pcmGetHostLatencyMs();
	}

	Result getPresentationPosition(uint64_t &frames, TimeSpec &ts) override {
	const AutoMutex lock(mFrameCountersMutex);

	nsecs_t nowNs = systemTime(SYSTEM_TIME_MONOTONIC);
	const uint64_t nowFrames = getPresentationFramesLocked(nowNs);
	auto presentedFrames = nowFrames - mMissedFrames;
	if (presentedFrames > mReceivedFrames) {
	// There is another underrun that is not yet accounted for in mMissedFrames
	auto delta = presentedFrames - mReceivedFrames;
	presentedFrames -= delta;
	// The last frame was presented some time ago, reflect that in the result
	nowNs -= delta * 1000000000 / mSampleRateHz;
	}
	mFrames = presentedFrames + mInitialFrames;

	frames = mFrames;
	ts = util::nsecs2TimeSpec(nowNs);
	return Result::OK;
	}

	uint64_t getPresentationFramesLocked(const nsecs_t nowNs) const {
	return uint64_t(mSampleRateHz) * ns2us(nowNs - mStartNs) / 1000000;
	}

	size_t calcAvailableFramesNowLocked() {
	const nsecs_t nowNs = systemTime(SYSTEM_TIME_MONOTONIC);
	auto presentationFrames = getPresentationFramesLocked(nowNs);
	if (mReceivedFrames + mMissedFrames < presentationFrames) {
	// There has been an underrun
	mMissedFrames = presentationFrames - mReceivedFrames;
	}
	size_t pendingFrames = mReceivedFrames + mMissedFrames - presentationFrames;
	return mRingBuffer.capacity() / mFrameSize - pendingFrames;
	}

	size_t calcWaitFramesNowLocked(const size_t requestedFrames) {
	const size_t availableFrames = calcAvailableFramesNowLocked();
	return (requestedFrames > availableFrames)
	? (requestedFrames - availableFrames) : 0;
	}

	size_t write(float volume, size_t bytesToWrite, IReader &reader) {
	const AutoMutex lock(mFrameCountersMutex);

	size_t framesLost = 0;
	const size_t waitFrames = calcWaitFramesNowLocked(bytesToWrite / mFrameSize);
	const auto blockUntil =
	std::chrono::high_resolution_clock::now() +
	+ std::chrono::microseconds(waitFrames * 1000000 / mSampleRateHz);

	while (bytesToWrite > 0) {
	if (mRingBuffer.waitForProduceAvailable(blockUntil
	+ std::chrono::microseconds(kMaxJitterUs))) {
	auto produceChunk = mRingBuffer.getProduceChunk();
	if (produceChunk.size >= bytesToWrite) {
	// Since the ring buffer has more bytes free than we need,
	// make sure we are not too early here: tinyalsa is jittery,
	// we don't want to go faster than SYSTEM_TIME_MONOTONIC
	std::this_thread::sleep_until(blockUntil);
	}

	const size_t szFrames =
	std::min(produceChunk.size, bytesToWrite) / mFrameSize;
	const size_t szBytes = szFrames * mFrameSize;
	LOG_ALWAYS_FATAL_IF(reader(produceChunk.data, szBytes) < szBytes);

	aops::multiplyByVolume(volume,
	static_cast<int16_t *>(produceChunk.data),
	szBytes / sizeof(int16_t));

	LOG_ALWAYS_FATAL_IF(mRingBuffer.produce(szBytes) < szBytes);
	mReceivedFrames += szFrames;
	bytesToWrite -= szBytes;
	} else {
	ALOGV("TinyalsaSink::%s:%d pcm_write was late reading "
	"frames, dropping %zu us of audio",
	__func__, __LINE__,
	size_t(1000000 * bytesToWrite / mFrameSize / mSampleRateHz));

	// drop old audio to make room for new
	const size_t bytesLost = mRingBuffer.makeRoomForProduce(bytesToWrite);
	framesLost += bytesLost / mFrameSize;

	while (bytesToWrite > 0) {
	auto produceChunk = mRingBuffer.getProduceChunk();
	const size_t szFrames =
	std::min(produceChunk.size, bytesToWrite) / mFrameSize;
	const size_t szBytes = szFrames * mFrameSize;
	LOG_ALWAYS_FATAL_IF(reader(produceChunk.data, szBytes) < szBytes);

	aops::multiplyByVolume(volume,
	static_cast<int16_t *>(produceChunk.data),
	szBytes / sizeof(int16_t));

	LOG_ALWAYS_FATAL_IF(mRingBuffer.produce(szBytes) < szBytes);
	mReceivedFrames += szFrames;
	bytesToWrite -= szBytes;
	}
	break;
	}
	}

	return framesLost;
	}

	void consumeThread() {
	util::setThreadPriority(PRIORITY_URGENT_AUDIO);
	std::vector<uint8_t> writeBuffer(mWriteSizeFrames * mFrameSize);

	while (mConsumeThreadRunning) {
	if (mRingBuffer.waitForConsumeAvailable(
	std::chrono::high_resolution_clock::now()
	+ std::chrono::microseconds(100000))) {
	size_t szBytes;
	{
	auto chunk = mRingBuffer.getConsumeChunk();
	szBytes = std::min(writeBuffer.size(), chunk.size);
	// We have to memcpy because the consumer holds the lock
	// into RingBuffer and pcm_write takes too long to hold
	// this lock.
	memcpy(writeBuffer.data(), chunk.data, szBytes);
	LOG_ALWAYS_FATAL_IF(mRingBuffer.consume(chunk, szBytes) < szBytes);
	}

	talsa::pcmWrite(mPcm.get(), writeBuffer.data(), szBytes);
	}
	}
	}

	static std::unique_ptr<TinyalsaSink> create(unsigned pcmCard,
	unsigned pcmDevice,
	const AudioConfig &cfg,
	size_t readerBufferSizeHint,
	uint64_t &frames) {
	(void)readerBufferSizeHint;
	auto sink = std::make_unique<TinyalsaSink>(pcmCard, pcmDevice,
	cfg, frames);
	if (sink->mMixer && sink->mPcm) {
	return sink;
	} else {
	return FAILURE(nullptr);
	}
	}

	private:
	const nsecs_t mStartNs;
	const unsigned mSampleRateHz;
	const unsigned mFrameSize;
	const unsigned mWriteSizeFrames;
	const uint64_t mInitialFrames;
	uint64_t &mFrames GUARDED_BY(mFrameCountersMutex);
	uint64_t mMissedFrames GUARDED_BY(mFrameCountersMutex) = 0;
	uint64_t mReceivedFrames GUARDED_BY(mFrameCountersMutex) = 0;
	RingBuffer mRingBuffer;
	talsa::Mixer mMixer;
	talsa::PcmPtr mPcm;
	std::thread mConsumeThread;
	std::atomic<bool> mConsumeThreadRunning = true;
	mutable Mutex mFrameCountersMutex;
	};

	struct NullSink : public DevicePortSink {
	NullSink(const AudioConfig &cfg, uint64_t &frames)
	: mStartNs(systemTime(SYSTEM_TIME_MONOTONIC))
	, mSampleRateHz(cfg.base.sampleRateHz)
	, mFrameSize(util::countChannels(cfg.base.channelMask) * sizeof(int16_t))
	, mInitialFrames(frames)
	, mFrames(frames) {}

	static int getLatencyMs(const AudioConfig &) {
	return 1;
	}

	Result getPresentationPosition(uint64_t &frames, TimeSpec &ts) override {
	const AutoMutex lock(mFrameCountersMutex);

	nsecs_t nowNs = systemTime(SYSTEM_TIME_MONOTONIC);
	const uint64_t nowFrames = getPresentationFramesLocked(nowNs);
	auto presentedFrames = nowFrames - mMissedFrames;
	if (presentedFrames > mReceivedFrames) {
	// There is another underrun that is not yet accounted for in mMissedFrames
	auto delta = presentedFrames - mReceivedFrames;
	presentedFrames -= delta;
	// The last frame was presented some time ago, reflect that in the result
	nowNs -= delta * 1000000000 / mSampleRateHz;
	}
	mFrames = presentedFrames + mInitialFrames;

	frames = mFrames;
	ts = util::nsecs2TimeSpec(nowNs);
	return Result::OK;
	}

	uint64_t getPresentationFramesLocked(const nsecs_t nowNs) const {
	return uint64_t(mSampleRateHz) * ns2us(nowNs - mStartNs) / 1000000;
	}

	size_t calcAvailableFramesNowLocked() {
	const nsecs_t nowNs = systemTime(SYSTEM_TIME_MONOTONIC);
	auto presentationFrames = getPresentationFramesLocked(nowNs);
	if (mReceivedFrames + mMissedFrames < presentationFrames) {
	// There has been an underrun
	mMissedFrames = presentationFrames - mReceivedFrames;
	}
	size_t pendingFrames = mReceivedFrames + mMissedFrames - presentationFrames;
	return sizeof(mWriteBuffer) / mFrameSize - pendingFrames;
	}

	size_t calcWaitFramesNowLocked(const size_t requestedFrames) {
	const size_t availableFrames = calcAvailableFramesNowLocked();
	return (requestedFrames > availableFrames)
	? (requestedFrames - availableFrames) : 0;
	}

	size_t write(float volume, size_t bytesToWrite, IReader &reader) override {
	(void)volume;
	const AutoMutex lock(mFrameCountersMutex);

	const size_t waitFrames = calcWaitFramesNowLocked(bytesToWrite / mFrameSize);
	const auto blockUntil =
	std::chrono::high_resolution_clock::now() +
	+ std::chrono::microseconds(waitFrames * 1000000 / mSampleRateHz);
	std::this_thread::sleep_until(blockUntil);

	while (bytesToWrite > 0) {
	size_t chunkSize =
	std::min(bytesToWrite, sizeof(mWriteBuffer)) / mFrameSize * mFrameSize;
	chunkSize = reader(mWriteBuffer, chunkSize);
	if (chunkSize > 0) {
	mReceivedFrames += chunkSize / mFrameSize;
	bytesToWrite -= chunkSize;
	} else {
	break; // reader failed
	}
	}

	return 0;
	}

	static std::unique_ptr<NullSink> create(const AudioConfig &cfg,
	size_t readerBufferSizeHint,
	uint64_t &frames) {
	(void)readerBufferSizeHint;
	return std::make_unique<NullSink>(cfg, frames);
	}

	private:
	const nsecs_t mStartNs;
	const unsigned mSampleRateHz;
	const unsigned mFrameSize;
	const uint64_t mInitialFrames;
	uint64_t &mFrames GUARDED_BY(mFrameCountersMutex);
	uint64_t mMissedFrames GUARDED_BY(mFrameCountersMutex) = 0;
	uint64_t mReceivedFrames GUARDED_BY(mFrameCountersMutex) = 0;
	char mWriteBuffer[1024];
	mutable Mutex mFrameCountersMutex;
	};

	} // namespace

	std::unique_ptr<DevicePortSink>
	DevicePortSink::create(size_t readerBufferSizeHint,
	const DeviceAddress &address,
	const AudioConfig &cfg,
	const hidl_vec<AudioInOutFlag> &flags,
	uint64_t &frames) {
	(void)flags;

	if (xsd::stringToAudioFormat(cfg.base.format) != xsd::AudioFormat::AUDIO_FORMAT_PCM_16_BIT) {
	ALOGE("%s:%d, unexpected format: '%s'", __func__, __LINE__, cfg.base.format.c_str());
	return FAILURE(nullptr);
	}

	if (GetBoolProperty("ro.boot.audio.tinyalsa.ignore_output", false)) {
	goto nullsink;
	}

	switch (xsd::stringToAudioDevice(address.deviceType)) {
	case xsd::AudioDevice::AUDIO_DEVICE_OUT_DEFAULT:
	case xsd::AudioDevice::AUDIO_DEVICE_OUT_SPEAKER:
	{
	auto sinkptr = TinyalsaSink::create(talsa::kPcmCard, talsa::kPcmDevice,
	cfg, readerBufferSizeHint, frames);
	if (sinkptr != nullptr) {
	return sinkptr;
	} else {
	ALOGW("%s:%d failed to create alsa sink for '%s'; creating NullSink instead.",
	__func__, __LINE__, address.deviceType.c_str());
	}
	}
	break;

	case xsd::AudioDevice::AUDIO_DEVICE_OUT_TELEPHONY_TX:
	case xsd::AudioDevice::AUDIO_DEVICE_OUT_BUS:
	ALOGW("%s:%d creating NullSink for '%s'.", __func__, __LINE__, address.deviceType.c_str());
	break;

	default:
	ALOGW("%s:%d unsupported device: '%s', creating NullSink", __func__, __LINE__, address.deviceType.c_str());
	break;
	}

	nullsink:
	return NullSink::create(cfg, readerBufferSizeHint, frames);
	}

	int DevicePortSink::getLatencyMs(const DeviceAddress &address, const AudioConfig &cfg) {
	switch (xsd::stringToAudioDevice(address.deviceType)) {
	default:
	ALOGW("%s:%d unsupported device: '%s'", __func__, __LINE__, address.deviceType.c_str());
	return FAILURE(-1);

	case xsd::AudioDevice::AUDIO_DEVICE_OUT_DEFAULT:
	case xsd::AudioDevice::AUDIO_DEVICE_OUT_SPEAKER:
	return TinyalsaSink::getLatencyMs(cfg);

	case xsd::AudioDevice::AUDIO_DEVICE_OUT_TELEPHONY_TX:
	case xsd::AudioDevice::AUDIO_DEVICE_OUT_BUS:
	return NullSink::getLatencyMs(cfg);
	}
	}

	bool DevicePortSink::validateDeviceAddress(const DeviceAddress& address) {
	switch (xsd::stringToAudioDevice(address.deviceType)) {
	default:
	ALOGW("%s:%d unsupported device: '%s'", __func__, __LINE__, address.deviceType.c_str());
	return FAILURE(false);

	case xsd::AudioDevice::AUDIO_DEVICE_OUT_DEFAULT:
	case xsd::AudioDevice::AUDIO_DEVICE_OUT_SPEAKER:
	case xsd::AudioDevice::AUDIO_DEVICE_OUT_TELEPHONY_TX:
	case xsd::AudioDevice::AUDIO_DEVICE_OUT_BUS:
	break;
	}

	return true;
	}

	} // namespace implementation
	} // namespace CPP_VERSION
	} // namespace audio
	} // namespace hardware
	} // namespace android