Exception in onSurfaceTextureUpdated when Thread.start() is invoked

Question

I'am writing Tess-two based OCR system for android and stumbled upon strange obstacle. I actually use TextureView connected with deprecated Camera and when I try to execute this code on my Huawei P8:

@Override
public void onSurfaceTextureUpdated(SurfaceTexture surface) {
    Log.d("frame", "update frame");
    if(btmQueue.size()<10)
        btmQueue.add(mTextureView.getBitmap());
    System.out.println(mOCRWorker.isAlive());
    if(mOCRWorker.isAlive()==false)
    {
        mOCRWorker.start();
    }
}

Thread mOCRWorker = new Thread(new Runnable() {

    @Override
    public void run() {
        Log.d("Ocr:", "Running thread!");
        if(apiInit==true) {
            if (btmQueue.size() > 0) {
                Bitmap bmp = btmQueue.pollFirst();
                baseAPI.setImage(bmp);
                String recognizedText = baseAPI.getUTF8Text();
                Log.d("Recognized: ", recognizedText);
            }
        }
        Log.d("Ocr:", "Thread finished!");

    }
});

I get this error:

E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.user.myApp, PID: 18386
java.lang.IllegalThreadStateException: Thread already started
at java.lang.Thread.checkNotStarted(Thread.java:864)
at java.lang.Thread.start(Thread.java:1074) [...]

I thought that that if isAlive() gives me false then my Thread is actually dead. Do you have any clue what is going on?

Answer 1

Okey, I figured it out: Method start() can't be invoked more than once for any Thread - even and especially when Thread were executed. I put while(ocrShouldWork) loop inside my Thread to keep it working till I turn it off.