What are the ramifications of not calling EndInvoke() on a delegate used to
asynchronously invoke a method with a void return?
I'm curious if this variation of the typical Begin/End Invoke pattern will have any
bad side effects.
(Please ignore any obvious typos. Outlook is a forgiving IDE)
//Some method I wish to invoke async.
private void Notify(IPerson person, Warning warning) {
Transport transport = GetPreferredTransport(person);
switch (transport) {
case (Transport.Email):
SendMail(person.Email, person.Name, warning);
break;
//case ...
}
person.Warnings.Add(warning, transport);
}
//Delegate used to invoke Notify() asynchronously.
private delegate void NotifyDelegate (IPerson person, Warning warning);
//Method used to perform async invoke of Notify() method.
void BeginNotify(IPerson person, Warning warning) {
NotifyDelegate nd = new NotifyDelegate(this.Notify);
AsyncCallback callback = new AsyncCallBack(this.EndNotify);
//Here's the beginning of the pattern change. I'm passing
//the reference from the person argument as the argument to
//Notify() as usual, and I'm also passing the reference as
//the argument to the delegate's State parameter.
nd.BeginInvoke(person, warning, callback, person);
}
//Callback method
void EndNotify(IAsyncResult ar) {
//This is my questionable change to the standard pattern.
//Skip casting ar to an AsyncResult.
//Skip getting reference to the NotifyDelegate instance
// that was created in BeginNotify(). (AsyncResult.AsyncDelegate)
//Skip calling AsyncDelegate.EndInvoke();
//Simply cast ar.AsyncState back to our IPerson.
IPerson person = (IPerson)ar.AsyncState;
//Use person.
...
}
Related question: What about not calling EndInvoke() on a delegate with non void
return signature when you don't care about the
return value?
Thanks, and
Keep Smilin'
Ed Stegman
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