SerialOutputManager " Run ending due to exception: null java.nio.BufferOverflowException " java.nio.BufferOverflowException

[mfran89]

Currently running an older version of the library due to a required external library that includes it. Running into this issue at run time where I get I this error

Run ending due to exception: null
java.nio.BufferOverflowException
	at java.nio.HeapByteBuffer.put(HeapByteBuffer.java:177)
	at java.nio.ByteBuffer.put(ByteBuffer.java:734)
	at *****
	at *****
	at com.hoho.android.usbserial.util.SerialInputOutputManager.step(SourceFile:168)
	at com.hoho.android.usbserial.util.SerialInputOutputManager.run(SourceFile:142)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:463)
	at java.util.concurrent.FutureTask.run(FutureTask.java:264)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1137)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:637)
	at java.lang.Thread.run(Thread.java:1012)

This happens when I am creating a connection to a USB device sometimes. I have been granted permission and can create a UsbSerialPort obj that I pass to and do the following

_serialManager = new SerialInputOutputManager(usbSerialPort);
 _serialManager.setListener(new SerialInputOutputManager.Listener() {
//code to handle onNewData() and onRunError()
}
_executorService.submit(_serialManager); //run on a parallel thread

The error I mentioned gets called at onRunError(). When this happens I do the following

if (_serialManager != null) {
            _serialManager.setListener(null);
            _serialManager.stop();
        }
        _serialManager = null;

I am not sure how to handle it, and why it's occurring.

[kai-morich]

without the actual values for at ***** lines it's hard to tell.

The only place where ByteBuffer.put is used, is writeAsync. Maybe you have to set a bigger buffer, as all writes are queued and executed after the next read.

[mfran89]

it is occurring in this function

_serialManager.setListener(new SerialInputOutputManager.Listener() {
            @Override
            public void onNewData(byte[] data) {
                // Sending Serial data to TCP
                    _tcpManager.writeAsync(data); 

This is the tcpmanager function

public void writeAsync(byte[] data) {
        synchronized (mWriteBufferLock) {
            mWriteBuffer.put(data); //this is the line of code that is crashing
            }
        }
    }

I have a parallel thread that has a similar object to SerialInputOutputManager but instead its a tcp server that grabs the serial data from this obj and passes it to another obj.

The buffer size for the SerialInputOutputManager obj inside the decompiled class is 4096 and I cannot change that. I have direct control over tcp manager buffer which is currently set to 4096, but I am not sure how changing that will make this better. Also I usually notice this null error after disconnecting and reconnecting , makes me think I am not properly closing the the serialInputOutputManager, or UsbSerialPort obj, or maybe just reopening is incorrect.

What I cant figure out is what the error is implying. Is it saying that the amount of bytes being sent by the SerialInputManager to the tcp manager is too much? Maybe a simple example in here might help me understand what I am doing wrong too.

Thanks
Mike

[kai-morich]

writes are queued and executed after the next read. If you cannot change the buffer size, you could add an additional buffer in front, but with that solution you still can only send 4k per read

[mfran89]

So what I ended up doing for now is increasing the buffer size of the object handing the onNewData() and for now it looks like it is working. Do you have any edge case protections I can use on top of increasing the size?