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/*
* (C) Finite State Machine Labs Inc. 2000 business@fsmlabs.com
*
* Released under the terms of GPL 2.
* Open RTLinux makes use of a patented process described in
* US Patent 5,995,745. Use of this process is governed
* by the Open RTLinux Patent License which can be obtained from
* www.fsmlabs.com/PATENT or by sending email to
* licensequestions@fsmlabs.com
*/
#include <stdio.h>
#include <errno.h>
#include <rtlinux_signal.h>
/* number of tests to run */
#define NUM_TESTS 32
/* time between each test */
#define HANGTIME (NSECS_PER_SEC / 32)
hrtime_t all_times[NUM_TESTS];
volatile int testnum;
void myhandler(int whatever)
{
if (testnum < NUM_TESTS) {
all_times[testnum] = gethrtime();
testnum++;
}
}
int main(void)
{
struct rtlinux_sigaction mysig, oldsig;
hrtime_t cur_drift, avg_drift, diff_time, worst_drift;
int i;
worst_drift = 0;
avg_drift = 0;
testnum = 0;
mysig.sa_handler = myhandler;
mysig.sa_flags = RTLINUX_SA_PERIODIC;
mysig.sa_period = HANGTIME;
if ((rtlinux_sigaction(RTLINUX_SIGTIMER0, &mysig, &oldsig))) {
perror("rtlinux_sigaction");
return (-1);
}
while (testnum < NUM_TESTS)
sleep(1);
mysig.sa_handler = RTLINUX_SIG_IGN;
if ((rtlinux_sigaction(RTLINUX_SIGTIMER0, &mysig, &oldsig))) {
perror("rtlinux_sigaction");
return (-1);
}
for (i = 1; i < NUM_TESTS; i++) {
diff_time = all_times[i] - all_times[i - 1];
cur_drift =
(diff_time <
HANGTIME) ? (HANGTIME -
diff_time) : (diff_time - HANGTIME);
avg_drift += cur_drift;
worst_drift =
(worst_drift < cur_drift) ? cur_drift : worst_drift;
}
avg_drift /= NUM_TESTS;
/* check to see if the worst case time was 50000 nanoseconds (50
* microseconds) or more */
fprintf(stderr,
"avg_drift: %d.%02d us\tworst_drift: %d.%02d us\n",
(long) avg_drift / 1000, (long) (avg_drift % 1000) / 10,
(long) worst_drift / 1000,
(long) (worst_drift % 1000) / 10);
if (worst_drift >= 50000) {
return (-1);
}
return (0);
}
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