- djm@cvs.openbsd.org 2012/04/11 13:16:19
[channels.c channels.h clientloop.c serverloop.c]
don't spin in accept() when out of fds (ENFILE/ENFILE) - back off for a
while; ok deraadt@ markus@
diff --git a/channels.c b/channels.c
index e5783b1..cacd2fe 100644
--- a/channels.c
+++ b/channels.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: channels.c,v 1.316 2012/03/29 23:54:36 dtucker Exp $ */
+/* $OpenBSD: channels.c,v 1.317 2012/04/11 13:16:19 djm Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -311,6 +311,7 @@
c->istate = CHAN_INPUT_OPEN;
c->flags = 0;
channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, 0);
+ c->notbefore = 0;
c->self = found;
c->type = type;
c->ctype = ctype;
@@ -1339,6 +1340,8 @@
}
if (newsock < 0) {
error("accept: %.100s", strerror(errno));
+ if (errno == EMFILE || errno == ENFILE)
+ c->notbefore = time(NULL) + 1;
return;
}
set_nodelay(newsock);
@@ -1482,6 +1485,8 @@
newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
if (newsock < 0) {
error("accept: %.100s", strerror(errno));
+ if (errno == EMFILE || errno == ENFILE)
+ c->notbefore = time(NULL) + 1;
return;
}
set_nodelay(newsock);
@@ -1514,7 +1519,10 @@
addrlen = sizeof(addr);
newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
if (newsock < 0) {
- error("accept from auth socket: %.100s", strerror(errno));
+ error("accept from auth socket: %.100s",
+ strerror(errno));
+ if (errno == EMFILE || errno == ENFILE)
+ c->notbefore = time(NULL) + 1;
return;
}
nc = channel_new("accepted auth socket",
@@ -1917,6 +1925,8 @@
if ((newsock = accept(c->sock, (struct sockaddr*)&addr,
&addrlen)) == -1) {
error("%s accept: %s", __func__, strerror(errno));
+ if (errno == EMFILE || errno == ENFILE)
+ c->notbefore = time(NULL) + 1;
return;
}
@@ -2067,16 +2077,21 @@
}
static void
-channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset)
+channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset,
+ time_t *unpause_secs)
{
static int did_init = 0;
u_int i, oalloc;
Channel *c;
+ time_t now;
if (!did_init) {
channel_handler_init();
did_init = 1;
}
+ now = time(NULL);
+ if (unpause_secs != NULL)
+ *unpause_secs = 0;
for (i = 0, oalloc = channels_alloc; i < oalloc; i++) {
c = channels[i];
if (c == NULL)
@@ -2087,10 +2102,30 @@
else
continue;
}
- if (ftab[c->type] != NULL)
- (*ftab[c->type])(c, readset, writeset);
+ if (ftab[c->type] != NULL) {
+ /*
+ * Run handlers that are not paused.
+ */
+ if (c->notbefore <= now)
+ (*ftab[c->type])(c, readset, writeset);
+ else if (unpause_secs != NULL) {
+ /*
+ * Collect the time that the earliest
+ * channel comes off pause.
+ */
+ debug3("%s: chan %d: skip for %d more seconds",
+ __func__, c->self,
+ (int)(c->notbefore - now));
+ if (*unpause_secs == 0 ||
+ (c->notbefore - now) < *unpause_secs)
+ *unpause_secs = c->notbefore - now;
+ }
+ }
channel_garbage_collect(c);
}
+ if (unpause_secs != NULL && *unpause_secs != 0)
+ debug3("%s: first channel unpauses in %d seconds",
+ __func__, (int)*unpause_secs);
}
/*
@@ -2099,7 +2134,7 @@
*/
void
channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
- u_int *nallocp, int rekeying)
+ u_int *nallocp, int *minwait_secs, int rekeying)
{
u_int n, sz, nfdset;
@@ -2122,7 +2157,8 @@
memset(*writesetp, 0, sz);
if (!rekeying)
- channel_handler(channel_pre, *readsetp, *writesetp);
+ channel_handler(channel_pre, *readsetp, *writesetp,
+ minwait_secs);
}
/*
@@ -2132,7 +2168,7 @@
void
channel_after_select(fd_set *readset, fd_set *writeset)
{
- channel_handler(channel_post, readset, writeset);
+ channel_handler(channel_post, readset, writeset, NULL);
}