On 12/12/07, Raimo Niskanen <[EMAIL PROTECTED]> wrote: > * A httpd server socket enters CLOSE_WAIT when the client > closes (or half-closes) its end and sends FIN to the > server TCP stack that replies ACK and enters CLOSE_WAIT. > The socket proceeds out of CLOSE_WAIT when httpd calls > close() on the socket. > > So, the remaining question is why httpd does not close the socket. > Even though KeepAlive is in effect, since the client has closed its > end there can come no more request on it, and the server > should be able to notice that the client has closed its > socket end either by recv() returning 0, or from a poll() > return value. The server also should be able to know if > it has more data to send to complete the reply. > I see no reason to hold the socket in CLOSE_WAIT the whole > KeepAliveTimeout time, and am interested to learn why.
WARNING: I'm not very experienced reading C code, so take my words with heaps of salt. The interesting code is most probably in http_main.c, http://www.openbsd.org/cgi-bin/cvsweb/src/usr.sbin/httpd/src/main/http_main.c The problem would be to "forget" calling ap_bclose() after ending a connection, either because all data has been sent or the connection has been aborted. What I can read with some confidence, is that keeping a socket open beyond sending any data is not intentional, and there is nothing (for me) which suggests that it would happen at all. Noob questions/statements ahead: The code, which implications (aside from the clear visible intention what the code *should do) are least clear to me for lingering_close() and lingerout() (is this a signal handler for SIG_ALRM?). I would suspect some kind of (signal?) race (not nessessarily there), in which ap_bclose() gets called on a different socket than intended (thus shutting down another connection as a side effect). BUT since the whole code doesn't run threaded, I can't come up with something which would actually suggest that. I would appreciate if someone told me whether my interpretation is rather wrong or rather right ;) --knitti
