From 689ba6e5657867eb3efbcb9a2dbec4aa98ddac5d Mon Sep 17 00:00:00 2001 From: Patrik Nyblom Date: Fri, 13 Apr 2012 17:23:30 +0200 Subject: gen_tcp: Make setopts(S,[{active,once}]) try a read This significantly reduces latency for tcp servers with high load, as we need not go into poll to get the next message. Maximum throughput may increase between 4 to 6 times compared to R15B. --- erts/emulator/drivers/common/inet_drv.c | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-) (limited to 'erts') diff --git a/erts/emulator/drivers/common/inet_drv.c b/erts/emulator/drivers/common/inet_drv.c index bf376f0494..76a9b55179 100644 --- a/erts/emulator/drivers/common/inet_drv.c +++ b/erts/emulator/drivers/common/inet_drv.c @@ -3124,6 +3124,7 @@ static int tcp_message(inet_descriptor* desc, const char* buf, int len) int i = 0; DEBUGF(("tcp_message(%ld): len = %d\r\n", (long)desc->port, len)); + /* XXX fprintf(stderr,"tcp_message send.\r\n"); */ i = LOAD_ATOM(spec, i, am_tcp); i = LOAD_PORT(spec, i, desc->dport); @@ -5426,6 +5427,7 @@ static int inet_set_opts(inet_descriptor* desc, char* ptr, int len) if (IS_SCTP(desc)) return sctp_set_opts(desc, ptr, len); #endif + /* XXX { int i; for(i=0;i= 5) { opt = *ptr++; @@ -5755,10 +5757,16 @@ skip_os_setopt: if (desc->active != old_active) sock_select(desc, (FD_READ|FD_CLOSE), (desc->active>0)); + /* XXX: UDP sockets could also trigger immediate read here NIY */ if ((desc->stype==SOCK_STREAM) && desc->active) { if (!old_active || (desc->htype != old_htype)) { /* passive => active change OR header type change in active mode */ - return 1; + /* Return > 1 if only active changed to INET_ONCE -> direct read if + header type is unchanged. */ + /* XXX fprintf(stderr,"desc->htype == %d, old_htype == %d, + desc->active == %d, old_active == %d\r\n",(int)desc->htype, + (int) old_htype, (int) desc->active, (int) old_active );*/ + return 1+(desc->htype == old_htype && desc->active == INET_ONCE); } return 0; } @@ -7592,17 +7600,27 @@ static ErlDrvSSizeT inet_ctl(inet_descriptor* desc, int cmd, char* buf, case INET_REQ_SETOPTS: { /* set options */ DEBUGF(("inet_ctl(%ld): SETOPTS\r\n", (long)desc->port)); + /* XXX fprintf(stderr,"inet_ctl(%ld): SETOPTS (len = %d)\r\n", (long)desc->port,(int) len); */ switch(inet_set_opts(desc, buf, len)) { case -1: return ctl_error(EINVAL, rbuf, rsize); case 0: return ctl_reply(INET_REP_OK, NULL, 0, rbuf, rsize); - default: /* active/passive change!! */ + case 1: /* * Let's hope that the descriptor really is a tcp_descriptor here. */ + /* fprintf(stderr,"Triggered tcp_deliver by setopt.\r\n"); */ tcp_deliver((tcp_descriptor *) desc, 0); return ctl_reply(INET_REP_OK, NULL, 0, rbuf, rsize); + default: + /* fprintf(stderr,"Triggered tcp_recv by setopt.\r\n"); */ + /* + * Same as above, but active changed to once w/o header type + * change, so try a read instead of just deliver. + */ + tcp_recv((tcp_descriptor *) desc, 0); + return ctl_reply(INET_REP_OK, NULL, 0, rbuf, rsize); } } @@ -9196,6 +9214,7 @@ static int tcp_inet_input(tcp_descriptor* desc, HANDLE event) #endif ASSERT(!INETP(desc)->is_ignored); DEBUGF(("tcp_inet_input(%ld) {s=%d\r\n", port, desc->inet.s)); + /* XXX fprintf(stderr,"tcp_inet_input(%ld) {s=%d}\r\n",(long) desc->inet.port, desc->inet.s); */ if (desc->inet.state == INET_STATE_ACCEPTING) { SOCKET s; unsigned int len; -- cgit v1.2.3