public void ReadAsync<T>(AsyncReadCallback<T> callback, AsyncException exception = null) {
    try {
        Thread thread = new Thread(new ThreadStart(() => {
            try {
                T request = ReadSync<T>();
                callback.Invoke(ref request);
            } catch(Exception e) {
                if(exception == null) {
                    throw e;
                }
                exception.Invoke(e);
            }
        }));
        thread.Start();
    } catch (Exception e) {
        if(exception == null) {
            throw e;
        }
        exception.Invoke(e);
    }
}

stream.ReadAsync((string result) => {
    Console.WriteLine("receive: "+result);
},(Exception e) => {
    Console.WriteLine("exception: "+e.Message);
});

public async Task<T> ReadAsync<T>() {
    return ReadSync<T>();
}

Task<string> taskRead = stream.ReadAsync<string>();
...
string data = await taskRead;
Console.WriteLine(data);