testcases/lib: Add tst_sleep

So that we can finally sleep for less than 1 second in shell testcases.

+ documentation in the test-writing-guidelines

Signed-off-by: Cyril Hrubis <chrubis@suse.cz>

3 files changed, 109 insertions, 2 deletions

diff --git a/testcases/lib/.gitignore b/testcases/lib/.gitignore
new file mode 100644
index 000000000..8886b34c4
--- /dev/null
+++ b/testcases/lib/.gitignore
@@ -0,0 +1 @@
+tst_sleep
diff --git a/testcases/lib/Makefile b/testcases/lib/Makefile
index 88c7344ff..0bfb149eb 100644
--- a/testcases/lib/Makefile
+++ b/testcases/lib/Makefile
@@ -24,8 +24,8 @@ top_srcdir		?= ../..
 
 include $(top_srcdir)/include/mk/env_pre.mk
 
-INSTALL_TARGETS		:= *.sh
+INSTALL_TARGETS		:= *.sh tst_sleep
 
-MAKE_TARGETS		:=
+MAKE_TARGETS		:= tst_sleep
 
 include $(top_srcdir)/include/mk/generic_leaf_target.mk
diff --git a/testcases/lib/tst_sleep.c b/testcases/lib/tst_sleep.c
new file mode 100644
index 000000000..b1d95cb6f
--- /dev/null
+++ b/testcases/lib/tst_sleep.c
@@ -0,0 +1,106 @@
+/*
+ * Copyright (c) 2016 Cyril Hrubis <chrubis@suse.cz>
+ *
+ * This program 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 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+
+static void print_help(void)
+{
+	printf("Usage: tst_usleep interval[s|ms|us]\n\n");
+	printf("       If no unit is specified the interval is in seconds\n");
+}
+
+static struct unit {
+	const char *unit;
+	long mul;
+} units[] = {
+	{"",   1000000},
+	{"s",  1000000},
+	{"ms", 1000},
+	{"us", 1},
+};
+
+static unsigned int units_len = sizeof(units) / sizeof(*units);
+
+int main(int argc, char *argv[])
+{
+	int opt;
+	long interval, secs = 0, usecs = 0;
+	unsigned int i;
+	char *end;
+
+	while ((opt = getopt(argc, argv, ":h")) != -1) {
+		switch (opt) {
+		case 'h':
+			print_help();
+			return 0;
+		default:
+			print_help();
+			return 1;
+		}
+	}
+
+	if (optind >= argc) {
+		fprintf(stderr, "ERROR: Expected interval argument\n\n");
+		print_help();
+		return 1;
+	}
+
+	interval = strtol(argv[optind], &end, 10);
+
+	if (argv[optind] == end) {
+		fprintf(stderr, "ERROR: Invalid interval '%s'\n\n",
+		        argv[optind]);
+		print_help();
+		return 1;
+	}
+
+	for (i = 0; i < units_len; i++) {
+		if (!strcmp(units[i].unit, end))
+			break;
+	}
+
+	if (i >= units_len) {
+		fprintf(stderr, "ERROR: Invalid interval unit '%s'\n\n", end);
+		print_help();
+		return 1;
+	}
+
+	if (units[i].mul == 1000000)
+		secs = interval;
+
+	if (units[i].mul == 1000) {
+		secs = interval / 1000;
+		usecs = (interval % 1000) * 1000;
+	}
+
+	if (units[i].mul == 1) {
+		secs = interval / 1000000;
+		usecs = interval % 1000000;
+	}
+
+	if (secs)
+		sleep(secs);
+
+	if (usecs)
+		usleep(usecs);
+
+	return 0;
+}