Lighttpd

i tested with a setup like client->lighty (mod_proxy)->server. Client uploads a file and server will exit as soon as it accepts the connection. lighty works fine with epoll where it closes the connection properly (EPOLLHUP). But for kqueue and select, sendfile() throws 'Socket is not connected' and returns -2. The fds are not removed and sits in handle-req state.

if (-2 == ret) { /* remote close */
log_error_write(srv, FILE, LINE, "ssd", "write failed, remote connection close:", strerror(errno), errno);
return HANDLER_WAIT_FOR_EVENT;
}

Below is truss output taken in FreeBSD 7.0. I can reproduce it and give you further details if needed.

Truss Output:
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5.761943487 0.000028216 write(5,"2009-12-02 20:20:10: (mod_proxy."...,78) = 78 (0x4e)
5.762071436 0.000043581 socket(PF_INET,SOCK_STREAM,0) = 9 (0x9)
5.762358903 0.000024584 fcntl(9,F_SETFD,FD_CLOEXEC) = 0 (0x0)
5.762460033 0.000023746 fcntl(9,F_SETFL,O_NONBLOCK|0x2) = 0 (0x0)
5.762650280 0.000084088 connect(9,{ AF_INET 172.16.0.230:85 },16) ERR#36 'Operation now in progress'
5.762806725 0.000035200 write(5,"2009-12-02 20:20:10: (mod_proxy."...,59) = 59 (0x3b)
5.763022674 0.000033803 kevent(7,{0x9,EVFILT_WRITE,EV_ADD|EV_CLEAR,0,0x0,0x0},1,0x0,0,{0.000000000}) = 0 (0x0)
5.763169900 0.000029054 kevent(7,{0x8,EVFILT_READ,EV_DELETE,0,0x0,0x0},1,0x0,0,{0.000000000}) = 0 (0x0)
5.763276617 0.000021790 gettimeofday({1259765410.396380},0x0) = 0 (0x0)
5.763395068 0.000029333 kevent(7,0x0,0,{0x9,EVFILT_WRITE,EV_CLEAR,0,0x8218,0x0},7208,{1.000000000}) = 1 (0x1)
5.763539500 0.000032127 write(5,"2009-12-02 20:20:10: (mod_proxy."...,62) = 62 (0x3e)
5.763663258 0.000027657 kevent(7,{0x9,EVFILT_WRITE,EV_DELETE,0,0x0,0x0},1,0x0,0,{0.000000000}) = 0 (0x0)
5.763794001 0.000023187 getsockopt(0x9,0xffff,0x1007,0xbfbfe8d4,0xbfbfe8d0,0xbfbfe888) = 0 (0x0)
5.763915246 0.000029613 write(5,"2009-12-02 20:20:10: (mod_proxy."...,74) = 74 (0x4a)
5.764110522 0.000070121 writev(0x9,0xbfbfc7f8,0x1,0x0,0x0,0x0) = 227 (0xe3)
5.764356642 0.000126552 stat("/var/tmp/lighttpd-upload-bqDHIm",{mode=-rw------- ,inode=898063,size=300000,blksize=
4096}) = 0 (0x0)
5.764534878 0.000052242 open("/var/tmp/lighttpd-upload-bqDHIm",O_RDONLY,027757743344) = 10 (0xa)
5.764636846 0.000030451 close(10) = 0 (0x0)
5.764815081 0.000052241 open("/var/tmp/lighttpd-upload-bqDHIm",O_RDONLY,05023107000) = 10 (0xa)
5.764912579 0.000021511 fcntl(10,F_SETFD,FD_CLOEXEC) = 0 (0x0)
5.765151157 0.000151975 sendfile(0xa,0x9,0x0,0x0,0x493e0,0x0) ERR#35 'Resource temporarily unavailable'
5.765324922 0.000033244 kevent(7,{0x9,EVFILT_WRITE,EV_ADD|EV_CLEAR,0,0x0,0x0},1,0x0,0,{0.000000000}) = 0 (0x0)
5.765436948 0.000021791 gettimeofday({1259765410.398541},0x0) = 0 (0x0)
5.766587653 0.001062147 kevent(7,0x0,0,{0x9,EVFILT_WRITE,EV_CLEAR|EV_EOF,54,0x8218,0x0},7208,{1.000000000}) = 1 (0x1)
5.766791589 0.000034921 write(5,"2009-12-02 20:20:10: (mod_proxy."...,62) = 62 (0x3e)
5.767008935 0.000054756 sendfile(0xa,0x9,0x8000,0x0,0x413e0,0x0) ERR#57 'Socket is not connected'
5.767181303 0.000034082 write(5,"2009-12-02 20:20:10: (mod_proxy."...,106) = 106 (0x6a)
5.767273773 0.000021790 gettimeofday({1259765410.400378},0x0) = 0 (0x0)
6.767701481 1.000335238 kevent(7,0x0,0,{},7208,{1.000000000}) = 0 (0x0)
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