Merijn Bosma wrote: > I've been using ICS for quite a while now, and a few days ago I came > across something strange. > One of our larger customers had some extra modules installed, causing > a lot of more tcp clients connecting to the tcp server. > > Every now and then (somewhere between 1 minute and 3 hours) the tcp > server would get up to 100% cpu utilization out of the blue. > After some searching we discovered that this was caused by the > OnDataAvailable event for one of the connected clients being > called continuously. > Now the mystery: > If I understood correct, you can get an endless loop if you don't read > all received data in the OnDataAvailable event.
You get a real infinite loop only if you called Receive() with a buffer size of zero. > The event will > keep being fired until all data is read, unless you add > wsoNoReceiveLoop. With option wsoNoReceiveLoop turned on OnDataAvailable will also trigger again and again as long as data is available. The difference is that the app. is given a chance to call its message pump between two OnDataAvailable events. As a result CPU utilization becomes lower. This may however also lower transfer rates a bit. > > The thing is that we _always_ call ReceiveStr() in the OnDataAvailable > event, I think this should always read all data received. Depends on LineMode, if LineMode is TRUE ReceiveStr() just reads a single line. > Is this a bug in ReceiveStr() or a bug regarding wsoNoReceiveLoop? I don't think it's a bug, wsoNoReceiveLoop is an option turned off by default for backwards compatibility. -- Arno Garrels [TeamICS] http://www.overbyte.be/eng/overbyte/teamics.html -- To unsubscribe or change your settings for TWSocket mailing list please goto http://lists.elists.org/cgi-bin/mailman/listinfo/twsocket Visit our website at http://www.overbyte.be
