services/oboeservice/AAudioServiceStreamBase.h

/*
 * Copyright (C) 2016 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.
 */

#ifndef AAUDIO_AAUDIO_SERVICE_STREAM_BASE_H
#define AAUDIO_AAUDIO_SERVICE_STREAM_BASE_H

#include <assert.h>
#include <mutex>

#include "fifo/FifoBuffer.h"
#include "binding/IAAudioService.h"
#include "binding/AudioEndpointParcelable.h"
#include "binding/AAudioServiceMessage.h"
#include "utility/AAudioUtilities.h"

#include "SharedRingBuffer.h"
#include "AAudioThread.h"

namespace aaudio {

// We expect the queue to only have a few commands.
// This should be way more than we need.
#define QUEUE_UP_CAPACITY_COMMANDS (128)

/**
 * Base class for a stream in the AAudio service.
 */
class AAudioServiceStreamBase
    : public Runnable  {

public:
    AAudioServiceStreamBase();
    virtual ~AAudioServiceStreamBase();

    enum {
        ILLEGAL_THREAD_ID = 0
    };

    // -------------------------------------------------------------------
    /**
     * Open the device.
     */
    virtual aaudio_result_t open(const aaudio::AAudioStreamRequest &request,
                                 aaudio::AAudioStreamConfiguration &configurationOutput) = 0;

    virtual aaudio_result_t close();

    /**
     * Start the flow of data.
     */
    virtual aaudio_result_t start();

    /**
     * Stop the flow of data such that start() can resume with loss of data.
     */
    virtual aaudio_result_t pause();

    /**
     * Stop the flow of data after data in buffer has played.
     */
    virtual aaudio_result_t stop();

    /**
     *  Discard any data held by the underlying HAL or Service.
     */
    virtual aaudio_result_t flush();

    // -------------------------------------------------------------------

    /**
     * Send a message to the client.
     */
    aaudio_result_t sendServiceEvent(aaudio_service_event_t event,
                                     double  dataDouble = 0.0,
                                     int64_t dataLong = 0);

    /**
     * Fill in a parcelable description of stream.
     */
    aaudio_result_t getDescription(AudioEndpointParcelable &parcelable);


    void setRegisteredThread(pid_t pid) {
        mRegisteredClientThread = pid;
    }

    pid_t getRegisteredThread() const {
        return mRegisteredClientThread;
    }

    int32_t getFramesPerBurst() const {
        return mFramesPerBurst;
    }

    int32_t calculateBytesPerFrame() const {
        return mSamplesPerFrame * AAudioConvert_formatToSizeInBytes(mAudioFormat);
    }

    void run() override; // to implement Runnable

    void processError();

protected:
    aaudio_result_t writeUpMessageQueue(AAudioServiceMessage *command);

    aaudio_result_t sendCurrentTimestamp();

    virtual aaudio_result_t getFreeRunningPosition(int64_t *positionFrames, int64_t *timeNanos) = 0;

    virtual aaudio_result_t getDownDataDescription(AudioEndpointParcelable &parcelable) = 0;

    aaudio_stream_state_t               mState = AAUDIO_STREAM_STATE_UNINITIALIZED;

    pid_t              mRegisteredClientThread = ILLEGAL_THREAD_ID;

    SharedRingBuffer*  mUpMessageQueue;
    std::mutex         mLockUpMessageQueue;

    AAudioThread        mAAudioThread;
    // This is used by one thread to tell another thread to exit. So it must be atomic.
    std::atomic<bool>   mThreadEnabled;

    aaudio_format_t    mAudioFormat = AAUDIO_FORMAT_UNSPECIFIED;
    int32_t            mFramesPerBurst = 0;
    int32_t            mSamplesPerFrame = AAUDIO_UNSPECIFIED;
    int32_t            mSampleRate = AAUDIO_UNSPECIFIED;
    int32_t            mCapacityInFrames = AAUDIO_UNSPECIFIED;
};

} /* namespace aaudio */

#endif //AAUDIO_AAUDIO_SERVICE_STREAM_BASE_H