WCF - calling a void service (is it still synchronous)?

Basically, if my service is: public void DoSomethingThatTakesAwhile() { ... }, will the call to that service cause my application to wait for the method to finish?

I ask because I don't want my caller to be able to continue until that method finishes in case the method needs to throw a fault exceptio开发者_JAVA技巧n.

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Yes, the call is synchronous, unless the operation is marked with [OperationContract(IsOneWay = true)]