[PATCH 1/6] cyclictest: Centralize clock option parsing

["Thomas Weißschuh (Schneider Electric)" <thomas.weissschuh@linutronix.de>]

Currently the lookup of the clockid from the commandline options is done
in multiple places. This makes the addition of symbolic clock names and
new clocks cumbersome.

Move all of the clock option parsing into a new helper function.

As a side-effect fix an off-by-one error in the validation of the
clock command line argument.

The new variable can not be named 'clock' as that would conflict with
the libc function of the same name.

Signed-off-by: Thomas Weißschuh (Schneider Electric) <thomas.weissschuh@linutronix.de>
---
 src/cyclictest/cyclictest.c | 35 ++++++++++++++++++-----------------
 1 file changed, 18 insertions(+), 17 deletions(-)

diff --git a/src/cyclictest/cyclictest.c b/src/cyclictest/cyclictest.c
index 960c90560668..592cf9d9387d 100644
--- a/src/cyclictest/cyclictest.c
+++ b/src/cyclictest/cyclictest.c
@@ -1022,7 +1022,7 @@ static int priority;
 static int policy = SCHED_OTHER;	/* default policy if not specified */
 static int num_threads = 1;
 static int max_cycles;
-static int clocksel = 0;
+static clockid_t used_clock;
 static int quiet;
 static int interval = DEFAULT_INTERVAL;
 static int distance = -1;
@@ -1031,10 +1031,17 @@ static struct bitmask *main_affinity_mask = NULL;
 static int smp = 0;
 static int setaffinity = AFFINITY_UNSPECIFIED;
 
-static int clocksources[] = {
-	CLOCK_MONOTONIC,
-	CLOCK_REALTIME,
-};
+static int handleclock(const char *clockarg)
+{
+	if (strcmp(clockarg, "0") == 0)
+		used_clock = CLOCK_MONOTONIC;
+	else if (strcmp(clockarg, "1") == 0)
+		used_clock = CLOCK_REALTIME;
+	else
+		return 1;
+
+	return 0;
+}
 
 static void handlepolicy(char *polname)
 {
@@ -1195,7 +1202,7 @@ static void process_options(int argc, char *argv[], int max_cpus)
 			tracelimit = atoi(optarg); break;
 		case 'c':
 		case OPT_CLOCK:
-			clocksel = atoi(optarg); break;
+			error |= handleclock(optarg); break;
 		case OPT_DEFAULT_SYSTEM:
 			power_management = 1; break;
 		case 'd':
@@ -1377,9 +1384,6 @@ static void process_options(int argc, char *argv[], int max_cpus)
 			      "on this processor\n");
 	}
 
-	if (clocksel < 0 || clocksel > ARRAY_SIZE(clocksources))
-		error = 1;
-
 	if (oscope_reduction < 1)
 		error = 1;
 
@@ -1983,7 +1987,6 @@ int main(int argc, char **argv)
 		warn("High resolution timers not available\n");
 
 	if (check_clock_resolution) {
-		int clock;
 		uint64_t diff;
 		int k;
 		uint64_t min_non_zero_diff = UINT64_MAX;
@@ -1994,9 +1997,7 @@ int main(int argc, char **argv)
 		struct timespec *time;
 		int times;
 
-		clock = clocksources[clocksel];
-
-		if (clock_getres(clock, &res))
+		if (clock_getres(used_clock, &res))
 			warn("clock_getres failed");
 		else
 			reported_resolution = (NSEC_PER_SEC * res.tv_sec) + res.tv_nsec;
@@ -2009,9 +2010,9 @@ int main(int argc, char **argv)
 		 * This will reliably capture resolution <= 500 usec.
 		 */
 		times = 1000;
-		clock_gettime(clock, &prev);
+		clock_gettime(used_clock, &prev);
 		for (k=0; k < times; k++)
-			clock_gettime(clock, &now);
+			clock_gettime(used_clock, &now);
 
 		diff = calcdiff_ns(now, prev);
 		if (diff == 0) {
@@ -2035,7 +2036,7 @@ int main(int argc, char **argv)
 		time = calloc(times, sizeof(*time));
 
 		for (k=0; k < times; k++)
-			clock_gettime(clock, &time[k]);
+			clock_gettime(used_clock, &time[k]);
 
 		info(ct_debug, "For %d consecutive calls to clock_gettime():\n", times);
 		info(ct_debug, "time, delta time (nsec)\n");
@@ -2193,7 +2194,7 @@ int main(int argc, char **argv)
 		}
 		if (priospread)
 			priority--;
-		par->clock = clocksources[clocksel];
+		par->clock = used_clock;
 		par->mode = mode;
 		par->timermode = timermode;
 		par->signal = signum;

-- 
2.53.0