Francois Piette wrote: >> I do not know how to write this as an async component method w/o >> a timer, but I can write it as a sync method by some wait >> function which processes messages and either starts retransmissions >> or triggers a final timeout when no response hasbeen received. > > There is no real differnece in using a TTimer or using > MsgWaitForMultipleObject. The code you place when > MsgWaitForMultipleObject return with a timeout is the code you put in > TTimer event.
What's annoying is that a TTimer creates a window and also requires ExtCtrls.pas to be included. I also wanted to provide sync as well as asyc methods. > > For short times, less than 250 mS, MsgWaitForMultipleObject is better > than TTimer. The annoying part of MsgWaitForMultipleObject is that > you have to make a loop and call the message pump. That is really > annoyng when you don't know what is the message pump, for example in > a thread. Can you please explain why that's a problem. In a thread, when MsgWaitForMultipleObjects returns due to pending message(s) I use Peekmessage() and dispatch them, why isn't it effective? --- Arno Garrels [TeamICS] http://www.overbyte.be/eng/overbyte/teamics.html > TTimer has not this problem. You just let it go, assuming > the message pump is working somewhere. > > TTimer was a limitation is old Windows version. I think today you can > have as many timers as you like (to be verifyed in MSDN). > > Contribute to the SSL Effort. Visit > http://www.overbyte.be/eng/ssl.html -- > [EMAIL PROTECTED] > Author of ICS (Internet Component Suite, freeware) > Author of MidWare (Multi-tier framework, freeware) > http://www.overbyte.be > > > ----- Original Message ----- > From: "Arno Garrels" <[EMAIL PROTECTED]> > To: "ICS support mailing" <twsocket@elists.org> > Sent: Thursday, August 17, 2006 12:26 PM > Subject: Re: [twsocket] UDP request/response proto > > >> Francois Piette wrote: >>>> Also, if I do not use some kind of a wait function >>>> in order to make a request blocking (like WaitUntilReady), >>>> it's mandatory to use a timer, correct? >>> >>> Sorry, I don't understand. >> >> Indeed badly expressed, I had the STUN proto in mind when I >> wrote it. >> In STUN, reliability is accomplished through client >> retransmissions. If no response is received by 1.6 >> seconds after the last request has been sent, the client SHOULD >> consider the transaction to have failed. In other words, requests >> would be sent at times 0ms, 100ms, 300ms, 700ms, 1500ms, 3100ms, >> 4700ms, 6300ms, and 7900ms. At 9500ms, the client considers the >> transaction to have failed if no response has been received. >> >> I do not know how to write this as an async component method w/o >> a timer, but I can write it as a sync method by some wait >> function which processes messages and either starts retransmissions >> or triggers a final timeout when no response hasbeen received. >> >> --- >> Arno Garrels [TeamICS] >> http://www.overbyte.be/eng/overbyte/teamics.html >> >> >>> Contribute to the SSL Effort. Visit >>> http://www.overbyte.be/eng/ssl.html -- >>> [EMAIL PROTECTED] >>> Author of ICS (Internet Component Suite, freeware) >>> Author of MidWare (Multi-tier framework, freeware) >>> http://www.overbyte.be >>> >>> ----- Original Message ----- >>> From: "Arno Garrels" <[EMAIL PROTECTED]> >>> To: "ICS support mailing" <twsocket@elists.org> >>> Sent: Thursday, August 17, 2006 10:27 AM >>> Subject: [twsocket] UDP request/response proto >>> >>> >>>> Hello, >>>> >>>> I UDP sendto a request datagram to the server, >>>> when OnDataAvailable triggers I call ReceiveFrom() >>>> in order to read the response. >>>> But I think OnDataAvailable is being triggered when >>>> any datagram addressed to that port arrives, even >>>> datagrams not sent by the destination server. How >>>> to handle this situation when some data arrive from >>>> and unexpected sender? Should I consider a pending >>>> request as failed or should I just ignore such packets? >>>> >>>> Also, if I do not use some kind of a wait function >>>> in order to make a request blocking (like WaitUntilReady), >>>> it's mandatory to use a timer, correct? >>>> >>>> --- >>>> Arno Garrels [TeamICS] >>>> http://www.overbyte.be/eng/overbyte/teamics.html >>>> >>>> -- >>>> To unsubscribe or change your settings for TWSocket mailing list >>>> please goto http://www.elists.org/mailman/listinfo/twsocket >>>> Visit our website at http://www.overbyte.be >> -- >> To unsubscribe or change your settings for TWSocket mailing list >> please goto http://www.elists.org/mailman/listinfo/twsocket >> Visit our website at http://www.overbyte.be -- To unsubscribe or change your settings for TWSocket mailing list please goto http://www.elists.org/mailman/listinfo/twsocket Visit our website at http://www.overbyte.be
