What is one way operation?

IsOneWay equal to true ensures that the client does not have to wait for the response. So methods marked by IsOneWay to true should always return void. In this the caller does not get anything in return so it is called as one-way communication. In order to understand one way implementation in WCF lets make a code walkthrough of a sample.

Figure 15.18: - One way in action
Above is the code snippet which describes practically how one way works in WCF. The above given code snippet is numbered. Below is the explanation according to the numbers marked in figure:
1 - This is the code snippet of the server service. We have created a method called as doHugeTask. doHugeTask basically makes the method sleep for 5000 MS and then displays the time when the task is completed.
2 - This code snippet is for client. It creates a proxy object of serviceIsOneWay and calls the doHugeTask method. After calling the doHugeTask the client execution continues ahead. So as a proof we display the time when the method calling was completed.
3 - This screen shot shows the output given by both server and client. The top window displays the server output and the below windows displays the client output.
So run the server program first i.e. ServiceIsOneWay and run the client later. You will see the client runs the doHugeTask and moves ahead. So the client completion time is less than the server. One more thing to understand is that one way does not give any notification back of completion. So it’s like fire and forget.