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/*
This file is part of GNUnet.
Copyright (C) 2001-2013 GNUnet e.V.
GNUnet is free software: you can redistribute it and/or modify it
under the terms of the GNU General Public License as published
by the Free Software Foundation, either version 3 of the License,
or (at your option) any later version.
GNUnet is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Affero General Public License for more details.
*/
/**
* @file util/test_scheduler_delay.c
* @brief testcase for delay of scheduler, measures how
* precise the timers are. Expect values between 0.2 and 2 ms on
* modern machines.
*/
#include "platform.h"
#include "gnunet_util_lib.h"
static struct GNUNET_TIME_Absolute target;
static int i;
static unsigned long long cumDelta;
#define INCR 47
#define MAXV 5000
/**
* Signature of the main function of a task.
*
* @param cls closure
*/
static void
test_task (void *cls)
{
struct GNUNET_TIME_Absolute now;
now = GNUNET_TIME_absolute_get ();
if (now.abs_value_us > target.abs_value_us)
cumDelta += (now.abs_value_us - target.abs_value_us);
else
cumDelta += (target.abs_value_us - now.abs_value_us);
target =
GNUNET_TIME_relative_to_absolute (GNUNET_TIME_relative_multiply
(GNUNET_TIME_UNIT_MICROSECONDS, i));
FPRINTF (stderr, "%s", ".");
if (i > MAXV)
{
FPRINTF (stderr, "%s", "\n");
return;
}
GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_relative_multiply
(GNUNET_TIME_UNIT_MICROSECONDS, i),
&test_task,
NULL);
i += INCR;
}
int
main (int argc, char *argv[])
{
GNUNET_log_setup ("test-scheduler-delay",
"WARNING",
NULL);
target = GNUNET_TIME_absolute_get ();
GNUNET_SCHEDULER_run (&test_task, NULL);
FPRINTF (stdout,
"Sleep precision: %llu microseconds (average delta). ",
cumDelta / (MAXV / INCR));
if (cumDelta <= 500 * MAXV / INCR)
FPRINTF (stdout, "%s", "Timer precision is excellent.\n");
else if (cumDelta <= 5000 * MAXV / INCR) /* 5 ms average deviation */
FPRINTF (stdout, "%s", "Timer precision is good.\n");
else if (cumDelta > 25000 * MAXV / INCR)
FPRINTF (stdout, "%s", "Timer precision is awful.\n");
else
FPRINTF (stdout, "%s", "Timer precision is acceptable.\n");
return 0;
}
/* end of test_scheduler_delay.c */
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