SO_LINGER has some side effects in closing a socket. From http://msdn.microsoft.com/en-us/library/ms737582%28v=vs.85%29.aspx: If the l_onoff member of the LINGER structure is zero (the default for a socket), closesocket returns immediately and the connection is gracefully closed in the background. Gracefully means sending remaining data and shutdown handshake. The "in the background" could mean that this could take a while and not finished when the app is already closed. Could also explain the fact that the problem is not always repeatable.
The additional CloseSocket doesn't return an error? Ludo -----Message d'origine----- De : Luca Olivetti [mailto:l...@ventoso.org] Envoyé : mercredi 25 mai 2011 20:52 À : Ararat Synapse Objet : Re: [Synalist] RE : tcp keepalive under windows, strange problem. Al 25/05/11 20:43, En/na Luca Olivetti ha escrit: > Al 25/05/11 18:33, En/na Ludo Brands ha escrit: >> Stupid question: > > Not stupid, maybe it's the cause of the problem > >> do you close the socket before quiting the application? Shutdown >> followed by CloseSocket? Or just CloseSocket? What SO_LINGER option >> is used? > > I call a TTCpBlockSocket.AbortSocket outside the thread, and an > additional CloseSocket (just in case) before returning from the > Execute loop. TTCPBlockSocket.AbortSocket calls > TTCPBlockSocket.CloseSocket and TTCPBlockSocket.CloseSocket calls > Shutdown internally. I don't set SO_LINGER, so it's at its default > value (whatever that is). Now that I think of it, if there were some data to send, there would have been no need to send keepalive packets, so I think that the SO_LINGER setting doesn't matter for the issue at hand. Bye -- Luca ---------------------------------------------------------------------------- -- vRanger cuts backup time in half-while increasing security. With the market-leading solution for virtual backup and recovery, you get blazing-fast, flexible, and affordable data protection. Download your free trial now. http://p.sf.net/sfu/quest-d2dcopy1 _______________________________________________ synalist-public mailing list synalist-public@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/synalist-public ------------------------------------------------------------------------------ vRanger cuts backup time in half-while increasing security. With the market-leading solution for virtual backup and recovery, you get blazing-fast, flexible, and affordable data protection. Download your free trial now. http://p.sf.net/sfu/quest-d2dcopy1 _______________________________________________ synalist-public mailing list synalist-public@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/synalist-public
