使用AudioRecord录音时，需要在UI线程的StopRecord方法、数据读取线程的while代码块之间加上锁，我使用了synchronized(byte[])。 但是按下停止录音按钮之后，StopRecord被阻塞了，while代码块却仍然在循环执行。

下面是抽象出来的简单代码，可以直接运行，同样出现了UI线程阻塞但无法获取锁的结果：

public class MainActivity extends ActionBarActivity implements View.OnClickListener{

    final byte[] lock = new byte[0];
    boolean isRecording = false;
    RecorderThread recorderThread;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Button buttonStart = (Button)findViewById(R.id.button_start);
        Button buttonStop = (Button)findViewById(R.id.button_stop);

        buttonStart.setOnClickListener(this);
        buttonStop.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()){
            case R.id.button_start:
                if(!isRecording){
                    // Initialize AudioRecord and startRecording
                    isRecording = true;
                    recorderThread = new RecorderThread();
                    recorderThread.start();
                }
                break;

            case R.id.button_stop:
                if(isRecording){
                    synchronized (lock){
                        // Stop AudioRecord and release
                        isRecording = false;
                    }
                }
                break;
        }
    }

    private class RecorderThread extends Thread{
        @Override
        public void run() {
            while (isRecording){
                synchronized (lock){
                    try{
                        // AudioRecord.read()
                        Thread.sleep(200);
                        Log.d("TAG","read a sample data");
                    }catch (InterruptedException e){
                        e.printStackTrace();
                    }
                }
            }
        }

    }
}