From 10673e56ee3f2b7206c0949480085920cf1d721c Mon Sep 17 00:00:00 2001
From: ppisa <ppisa>
Date: Wed, 16 Aug 2006 12:50:45 +0000
Subject: [PATCH] Program canping extended to provide option for selection of
 real-time priorities.

---
 src/canping.c | 67 ++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 66 insertions(+), 1 deletion(-)

diff --git a/src/canping.c b/src/canping.c
index 10c605e..eb829b3 100644
--- a/src/canping.c
+++ b/src/canping.c
@@ -20,6 +20,16 @@
 
 //#define DEBUG 1
 //#define DEBUG 2
+#define WITH_RTPRIO
+
+#ifdef WITH_RTPRIO
+#include <sched.h>
+
+int sched_policy = SCHED_OTHER;
+int sched_rtprio;
+
+#endif
+
 
 #ifndef DEBUG
 #define dbg(level, fmt, arg...) do {} while (0)
@@ -445,6 +455,28 @@ void start_slaves(int slaves, int first_id)
 	}
 }
 
+#ifdef WITH_RTPRIO
+int set_sched_policy_and_prio(int policy, int rtprio)
+{
+	struct sched_param scheduling_parameters;
+	int maxprio=sched_get_priority_max(policy);
+	int minprio=sched_get_priority_min(policy);
+
+	if((rtprio < minprio) || (rtprio > maxprio)) {
+		fprintf(stderr, "The priority for requested policy is out of <%d, %d> range\n",
+				minprio, maxprio);
+		return -1;
+	}
+
+	scheduling_parameters.sched_priority = rtprio;
+
+	if (0 != pthread_setschedparam(pthread_self(), policy, &scheduling_parameters))	{
+		perror("pthread_setschedparam error");
+	}
+	return 0;
+}
+#endif
+
 void print_help(void)
 {
 	printf("Usage: canping -m <master threads> [other options]\n"
@@ -461,6 +493,10 @@ void print_help(void)
 	       "  -w ms		wait ms miliseconds between sending pings\n"
 	       "  -y            synchronize threads before start (doesn't test race conditions\n"
 	       "                between open and read/write)\n"
+#ifdef WITH_RTPRIO
+	       "  -r            run at realtime priority\n"
+	       "  -R P:prio     run at realtime priority prio, policy RR or FF\n"
+#endif
 	       "\n"
 	       "Example: canping -m 10 -vv\n"
 		);
@@ -471,7 +507,7 @@ int parse_options(int argc, char *argv[])
 	int c;
 	
 	opterr = 0;
-	while ((c = getopt (argc, argv, "c:d:hi:l:m:os:t:vw:y")) != -1)
+	while ((c = getopt (argc, argv, "c:d:hi:l:m:os:t:vw:yrR:")) != -1)
 		switch (c)
 		{
 		case 'c':
@@ -513,6 +549,28 @@ int parse_options(int argc, char *argv[])
 		case 'y':
 			option_synch_start = 1;
 			break;
+#ifdef WITH_RTPRIO
+		case 'r':
+			sched_policy = SCHED_FIFO;
+			sched_rtprio = (sched_get_priority_min(SCHED_FIFO) +
+					sched_get_priority_max(SCHED_FIFO)) / 2;
+			break;
+		case 'R':
+			if(!isalpha(*optarg)) {
+				sched_policy = SCHED_FIFO;
+			} else if(!strncmp(optarg,"FF:",3)) {
+				sched_policy = SCHED_FIFO;
+				optarg += 3;
+			} else if(!strncmp(optarg,"RR:",3)) {
+				sched_policy = SCHED_RR;
+				optarg += 3;
+			} else {
+				fprintf (stderr, "Unknown policy %s\n", optarg);
+				exit(EXIT_BAD_PARAM);
+			}
+			sched_rtprio = atoi(optarg);
+			break;
+#endif
 		case '?':
 			if (isprint (optopt))
 				fprintf (stderr, "Unknown option `-%c'.\n", optopt);
@@ -606,6 +664,13 @@ int main(int argc, char *argv[])
 {
 	parse_options(argc, argv);
 
+#ifdef WITH_RTPRIO
+	if(sched_policy != SCHED_OTHER)
+		if(set_sched_policy_and_prio(sched_policy, sched_rtprio) <0)
+			exit(EXIT_BAD_PARAM);
+#endif
+
+
 	thread_list_init_head(&master_threads);
 	thread_list_init_head(&slave_threads);
 
-- 
2.39.2