On 07/06/2011 03:58 PM, Mladen Turk wrote:
On 07/06/2011 02:52 PM, Eric van der Maarel wrote:
Hi,
Recently I proposed a fix for the select version of apr_pollset_poll
implementation, that prevents cpu going to 100% when all clients have
disconnected
(http://mail-archives.apache.org/mod_mbox/apr-dev/201106.mbox/browser). It
actually provides the select impl. of poll with the ability to issue
APR_POLLHUPP return events.
Jeff, could you please have a look at it and post any remarks you might
have.
If Jeff can't, I can ;)
Ok. Just thought it'd be more Jeff's cup of tea. Thanks.
1. One byte is enough; eg. recv(s,&c, 1, MSG_PEEK)
sure
2. Not sure that other platforms *always* set POLLHUP for
half closed sockets.
It doesn't always set POLLHUP. When socket is in accepted state,
select() keeps it in the read set and reading with recv() returns 0
graceful disconnect, possibly sudden disconnect) then POLLHUP is set.
Seems appropriate to me. When recv() result <0 POLLERR flag is set.
Part of my concern is recv() can return 0 when a socket is ready for
accept(). We just cannot detect this situation proper. My assumption is
here that it cannot happen with sockets in the poller: they are in
accept()-ed state already.
3. Missing an actual .diff -u file
added
How do I get about to get a patch like this adopted in the apr source?
Create a proper patch. It can be a while until someone
does your homework :)
the diff enough?
Thanks,
Eric
Regards
diff -u select.c.orig select.c
--- select.c.orig 2009-10-02 18:24:00.000000000 +0200
+++ select.c 2011-07-07 14:55:29.000000000 +0200
@@ -149,6 +149,14 @@
break;
}
if (FD_ISSET(fd, &readset)) {
+ char c;
+ int r = recv(fd, &c, 1, MSG_PEEK);
+ if (r == 0) {
+ aprset[i].rtnevents |= APR_POLLHUP;
+ }
+ else if (r < 0) {
+ aprset[i].rtnevents |= APR_POLLERR;
+ }
aprset[i].rtnevents |= APR_POLLIN;
}
if (FD_ISSET(fd, &writeset)) {
@@ -399,6 +407,14 @@
pollset->p->result_set[j] = pollset->p->query_set[i];
pollset->p->result_set[j].rtnevents = 0;
if (FD_ISSET(fd, &readset)) {
+ char c;
+ int r = recv(fd, &c, 1, MSG_PEEK);
+ if (r == 0) {
+ pollset->p->result_set[j].rtnevents |= APR_POLLHUP;
+ }
+ else if (r < 0) {
+ pollset->p->result_set[j].rtnevents |= APR_POLLERR;
+ }
pollset->p->result_set[j].rtnevents |= APR_POLLIN;
}
if (FD_ISSET(fd, &writeset)) {
--
-------------------------------------------
| Eric van der Maarel |
| NEDAP IDEAS |
| eric.vandermaa...@nedap.com |
-------------------------------------------^[ZZ
