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+/*---------------------------------------------------------------
+ * Copyright (c) 2014
+ * Broadcom Corporation
+ * All Rights Reserved.
+ *---------------------------------------------------------------
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated
+ * documentation files (the "Software"), to deal in the Software
+ * without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute,
+ * sublicense, and/or sell copies of the Software, and to permit
+ * persons to whom the Software is furnished to do
+ * so, subject to the following conditions:
+ *
+ *
+ * Redistributions of source code must retain the above
+ * copyright notice, this list of conditions and
+ * the following disclaimers.
+ *
+ *
+ * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following
+ * disclaimers in the documentation and/or other materials
+ * provided with the distribution.
+ *
+ *
+ * Neither the name of Broadcom Coporation,
+ * nor the names of its contributors may be used to endorse
+ * or promote products derived from this Software without
+ * specific prior written permission.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE CONTIBUTORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ * ________________________________________________________________
+ *
+ * checkdelay.c
+ * Simple tool to measure mean/min/max of nanosleep
+ * by Robert J. McMahon (rjmcmahon@rjmcmahon.com, rmcmahon@broadcom.com)
+ * ------------------------------------------------------------------- */
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <ctype.h>
+#include <unistd.h>
+#include "headers.h"
+#include "util.h"
+#include "delay.h"
+#if HAVE_SCHED_SETSCHEDULER
+#include <sched.h>
+#ifdef HAVE_MLOCKALL
+#include <sys/mman.h>
+#endif
+#endif
+
+
+
+#define BILLION 1000000000
+#define MILLION 1000000
+
+int main (int argc, char **argv) {
+ double sum=0;
+ double time1, time2;
+ double delta, max=0, min=-1;
+ int ix, delay=1,loopcount=1000;
+ int c;
+ int clockgettime = 0, kalman = 0;
+#if HAVE_DECL_CPU_SET
+ int affinity = 0;
+#endif
+#if HAVE_SCHED_SETSCHEDULER
+ int realtime = 0;
+ struct sched_param sp;
+#endif
+#ifdef HAVE_CLOCK_GETTIME
+ struct timespec t1;
+#else
+ struct timeval t1;
+#endif
+
+ while ((c=getopt(argc, argv, "a:bkd:i:r")) != -1)
+ switch (c) {
+ case 'b':
+ clockgettime = 1;
+ break;
+ case 'k':
+ kalman = 1;
+ break;
+ case 'd':
+ delay = atoi(optarg);
+ break;
+ case 'i':
+ loopcount = atoi(optarg);
+ break;
+#if HAVE_DECL_CPU_SET
+ case 'a':
+ affinity=atoi(optarg);
+ break;
+#endif
+#if HAVE_SCHED_SETSCHEDULER
+ case 'r':
+ realtime = 1;
+ break;
+#endif
+ case '?':
+ fprintf(stderr,"Usage -b busyloop, -d usec delay, -i iterations"
+#if HAVE_DECL_CPU_SET
+ ", -a affinity"
+#endif
+#if HAVE_SCHED_SETSCHEDULER
+ ", -r realtime"
+#endif
+ "\n");
+ return 1;
+ default:
+ abort();
+ }
+
+#ifndef HAVE_NANOSLEEP
+ clockgettime = 1;
+#endif
+
+#if HAVE_SCHED_SETSCHEDULER
+ if (realtime) {
+ fprintf(stdout,"Setting scheduler to realtime via SCHED_RR\n");
+ // SCHED_OTHER, SCHED_FIFO, SCHED_RR
+ sp.sched_priority = sched_get_priority_max(SCHED_RR);
+ WARN_errno(sched_setscheduler(0, SCHED_RR, &sp) < 0,
+ "Client set scheduler");
+#ifdef HAVE_MLOCKALL
+ // lock the threads memory
+ WARN_errno(mlockall(MCL_CURRENT | MCL_FUTURE) != 0, "mlockall");
+#endif
+ }
+#if HAVE_DECL_CPU_SET
+ if (affinity) {
+ fprintf(stdout,"CPU affinity set to %d\n", affinity);
+ cpu_set_t myset;
+ CPU_ZERO(&myset);
+ CPU_SET(affinity,&myset);
+ }
+#endif
+#endif
+ if (loopcount > 1000)
+ fprintf(stdout,"Measuring %s over %.0e iterations using %d usec delay\n",
+ kalman ? "kalman" :
+ clockgettime ? "clock_gettime" : "nanosleep",
+ (double) loopcount, delay);
+ else
+ fprintf(stdout,"Measuring %s over %d iterations using %d usec delay\n",
+ kalman ? "kalman" :
+ clockgettime ? "clock_gettime" : "nanosleep",
+ loopcount, delay);
+ fflush(stdout);
+ for (ix=0; ix < loopcount; ix++) {
+ // Find the max jitter for delay call
+#ifdef HAVE_CLOCK_GETTIME
+ clock_gettime(CLOCK_REALTIME, &t1);
+ time1 = t1.tv_sec + (t1.tv_nsec / 1000000000.0);
+#else
+ gettimeofday( &t1, NULL );
+ time1 = t1.tv_sec + (t1.tv_usec / 1000000.0);
+#endif
+#ifdef HAVE_KALMAN
+ if (kalman) {
+ delay_kalman(delay);
+ } else
+#endif
+ if (clockgettime) {
+ delay_busyloop(delay);
+ } else {
+#ifdef HAVE_NANOSLEEP
+ delay_nanosleep(delay);
+#endif
+ }
+#ifdef HAVE_CLOCK_GETTIME
+ clock_gettime(CLOCK_REALTIME, &t1);
+ time2 = t1.tv_sec + (t1.tv_nsec / 1000000000.0);
+#else
+ gettimeofday( &t1, NULL );
+ time2 = t1.tv_sec + (t1.tv_usec / 1000000.0);
+#endif
+ delta = (time2 - time1) * 1e6;
+ if (delta > max) {
+ max = delta;
+ }
+ if (delta < min || min < 0) {
+ min = delta;
+ }
+ sum += (double) delta;
+ }
+ fprintf(stdout,"delay=%.03f/%.03f/%.03f usec (mean/min/max)\n",
+ (sum / loopcount), min, max);
+ return(0);
+}