[tpop3d-discuss][PATCH]: avoid tons of time() calls

[Arkadiusz Miskiewicz]

Hi,

I've just checked that on busy server I get
nearly 10000 time() calls per second!

# grep  19:36:04 OUT |grep time | wc -l
9668

where OUT is output from strace -tt -f -F -s 200 -p 5571 -o OUT
(5571 is main parent of all tpop3d childs).

Do we need to call it so often?

In most cases if (!(c = connections[i])) will just continue and I see no point
to check time every iteration.

--- netloop.c       2006-06-26 07:30:25.000000000 +0200
+++ netloop.c   2006-06-28 19:46:00.000000000 +0200
@@ -387,16 +387,20 @@
     static size_t i;
     size_t i0;
     time_t start;
+    int latency = 1;

     time(&start);

-    for (i0 = (i + max_connections - 1) % max_connections; time(NULL) < start 
+ LATENCY && i != i0; i = (i + 1) % max_connections) {
+    for (i0 = (i + max_connections - 1) % max_connections; latency && i != i0; 
i = (i + 1) % max_connections) {
         connection c;
         int r;

         if (!(c = connections[i]))
             continue;

+       if (time(NULL) >= start + LATENCY)
+               latency = 0;
+
         if (i > 0 && post_fork) {
             connections[0] = c;
             connections[i] = NULL;

-- 
Arkadiusz Miśkiewicz        PLD/Linux Team
arekm / maven.pl            http://ftp.pld-linux.org/