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authorPatrik Nyblom <[email protected]>2012-04-13 17:23:30 +0200
committerPatrik Nyblom <[email protected]>2012-05-04 11:47:18 +0200
commit689ba6e5657867eb3efbcb9a2dbec4aa98ddac5d (patch)
treeabcb8ceea7dcd0dd44a670f77c973ad0fe60802f /erts/emulator
parentc5d6ce6a07478c5ac19fdf2df244c4b837888d08 (diff)
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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.
Diffstat (limited to 'erts/emulator')
-rw-r--r--erts/emulator/drivers/common/inet_drv.c23
1 files changed, 21 insertions, 2 deletions
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<len;++i) fprintf(stderr,"0x%02X, ", (unsigned) ptr[i]); fprintf(stderr,"\r\n");} */
while(len >= 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;