public static void RegisterTask(this AsyncManager asyncManager, Func <AsyncCallback, IAsyncResult> beginDelegate, Action <IAsyncResult> endDelegate)
{
if (asyncManager == null)
{
throw new ArgumentNullException("asyncManager");
}
if (beginDelegate == null)
{
throw new ArgumentNullException("beginDelegate");
}
if (endDelegate == null)
{
throw new ArgumentNullException("endDelegate");
}
// need to wait to execute the callback until after BeginXxx() has completed
object delegateExecutingLockObj = new object();
AsyncCallback callback = ar => {
lock (delegateExecutingLockObj) { }
if (!ar.CompletedSynchronously)
{
try {
asyncManager.Sync(() => endDelegate(ar)); // called on different thread, so have to take application lock
}
catch {
// Need to swallow exceptions, as otherwise unhandled exceptions on a ThreadPool thread
// can bring down the entire worker process.
}
finally {
asyncManager.OutstandingOperations.Decrement();
}
}
};
IAsyncResult asyncResult;
asyncManager.OutstandingOperations.Increment();
try {
lock (delegateExecutingLockObj) {
asyncResult = beginDelegate(callback);
}
}
catch {
asyncManager.OutstandingOperations.Decrement();
throw;
}
if (asyncResult.CompletedSynchronously)
{
try {
endDelegate(asyncResult); // call on same thread
}
finally {
asyncManager.OutstandingOperations.Decrement();
}
}
}
