[libaums]: UsbWriteOperation class

protected void doWrite() throws IOException {
    if (this.state.compareAndSet(State.NEW, State.RUNNING)) {
        // some checks before write and create Output Stream
        if (!prepareForWrite()) {
            return;
        }
    }
    if ((this.state.get() == State.RUNNING)
            || this.state.compareAndSet(State.SUSPENDED, State.RUNNING)) {
        byte[] nextByte;
        try {
            // Integer.maxValue
            int executeCount = weight;
            do {
                // retrieves next block of data from queue
                nextByte = blockingQueue.poll();
                if (nextByte == null) {
                    //suspend because blocking queue is empty
                    suspend();
                    break;
                }
                if (isPoissonPill(nextByte)) {
                    state.set(State.COMPLETED);
                    Timber.tag(TAG).i("Write completed for the file %s", destFile.getPath());
                    break;
                } else {
                    // write data to device
                    outputStream.write(nextByte);
                    publishProgress(nextByte.length);
                    executeCount--;
                }
            } while (isExitCondition(executeCount));
            state.compareAndSet(State.RUNNING, State.SUSPENDED);
        } finally {
            if (State.COMPLETED == state.get()) {
                closeStreams();
                delegate.onWriteSuccess();
            }
        }
    }
}

// check EOF
private boolean isPoissonPill(byte[] nextByte) {
    return nextByte == Constants.EOF;
}

void createStream() throws USBException, IOException {
    // FileSystemService.getOutputStream will be called
    outputStream = api.getFileSystemService().getOutputStream(usbDevice, destFile);
    file = api.getFileSystemService().getUsbFile(usbDevice, destFile);
}

private void closeStreams() {
    try {
        if (outputStream != null) {
            outputStream.close();
            outputStream = null;
        }
    } catch (IOException e) {
        e.printStackTrace();
    }
}

@Override
public boolean suspend() {
    return this.state.compareAndSet(State.RUNNING, State.SUSPENDED);
}