[src/trunk]: src/external/bsd/libevent/dist/test Calibrate the amount of time...

[pgoyette <pgoyette%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/62be3a2e7543
branches:  trunk
changeset: 758612:62be3a2e7543
user:      pgoyette <pgoyette%NetBSD.org@localhost>
date:      Thu Nov 11 14:11:26 2010 +0000

description:
Calibrate the amount of time that a sleep() requires, and use that
interval instead of assuming that there are exactly 1000 real-time-clock
milliseconds per second!  On some ports when running under qemu, there
can be twice as many RTC milliseconds as expected.

This is part 2 of the changes required to make the libevent tests work
on port-amd64 under qemu.

diffstat:

 external/bsd/libevent/dist/test/regress.c |  34 ++++++++++++++++++++++++++++--
 1 files changed, 31 insertions(+), 3 deletions(-)

diffs (76 lines):

diff -r 469e2f4e8713 -r 62be3a2e7543 external/bsd/libevent/dist/test/regress.c
--- a/external/bsd/libevent/dist/test/regress.c Thu Nov 11 14:08:45 2010 +0000
+++ b/external/bsd/libevent/dist/test/regress.c Thu Nov 11 14:11:26 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: regress.c,v 1.1.1.1 2009/11/02 10:01:03 plunky Exp $   */
+/*     $NetBSD: regress.c,v 1.2 2010/11/11 14:11:26 pgoyette Exp $     */
 /*
  * Copyright (c) 2003, 2004 Niels Provos <provos%citi.umich.edu@localhost>
  * All rights reserved.
@@ -78,6 +78,8 @@
 static struct timeval tcalled;
 static struct event_base *global_base;
 
+static int interval;
+
 #define TEST1  "this is a test"
 #define SECONDS        1
 
@@ -183,6 +185,27 @@
 }
 
 static void
+calibrate(void)
+{
+       struct timeval start, end, diff;
+       int delta;
+
+       gettimeofday(&start, NULL);
+       sleep(SECONDS);
+       gettimeofday(&end, NULL);
+
+       timersub(&end, &start, &diff);
+
+       delta = diff.tv_sec * 1000 + diff.tv_usec / 1000;
+       if (delta < 0)
+               delta = -delta;
+
+       interval = delta;
+       fprintf(stdout, "Calibrated interval: %d sec = %d msec\n", SECONDS,
+               interval);
+}
+
+static void
 timeout_cb(int fd, short event, void *arg)
 {
        struct timeval tv;
@@ -194,7 +217,7 @@
        else
                evutil_timersub(&tset, &tcalled, &tv);
 
-       diff = tv.tv_sec*1000 + tv.tv_usec/1000 - SECONDS * 1000;
+       diff = tv.tv_sec*1000 + tv.tv_usec/1000 - interval;
        if (diff < 0)
                diff = -diff;
 
@@ -924,7 +947,7 @@
        evtimer_add(&ev, &tv);
 
        tv.tv_usec = 0;
-       tv.tv_sec = 1;
+       tv.tv_sec = SECONDS;
        event_loopexit(&tv);
 
        evutil_gettimeofday(&tv_start, NULL);
@@ -1625,6 +1648,11 @@
        if (signal(SIGPIPE, SIG_IGN) == SIG_ERR)
                return (1);
 #endif
+       /*
+        * Calibrate sleep() vs elapsed real-time
+        */
+       calibrate();
+
        setvbuf(stdout, NULL, _IONBF, 0);
 
        /* Initalize the event library */