time: add benchmarking capabilities.

Signed-off-by: Gediminas Jakutis <gediminas@varciai.lt>

2 files changed, 77 insertions, 0 deletions

diff --git a/src/time/benchmark.c b/src/time/benchmark.c
new file mode 100644
index 0000000..543275a
--- /dev/null
+++ b/src/time/benchmark.c
@@ -0,0 +1,76 @@
+/*
+ * The Rin Library – time module, benchmarking section
+ *
+ * Copyright (C) 2019 Gediminas Jakutis
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; version 2.1
+ * of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
+ */
+
+#include <time.h>
+#include <errno.h>
+#include <sys/resource.h>
+#include "rin/time.h"
+#include "time_private.h"
+
+#if defined CLOCK_MONOTONIC
+#	define RIN_CLOCK_WALL_COUNTER CLOCK_MONOTONIC
+#else
+#	define RIN_CLOCK_WALL_COUNTER CLOCK_REALTIME
+#endif /* defined CLOCK_MONOTONIC */
+
+static struct bench {
+	int status;
+	struct rusage runtime;
+	struct timespec wall;
+} bench = {0};
+
+
+int rin_bench_start(void)
+{
+	if (bench.status) {
+		return EAGAIN;
+	}
+
+	bench.status = 1;
+	clock_gettime(RIN_CLOCK_WALL_COUNTER, &bench.wall);
+	getrusage(RUSAGE_SELF, &bench.runtime);
+
+	return 0;
+}
+
+int rin_bench_stop(struct rin_bench_result *res)
+{
+	struct timespec wall;
+	struct rusage run;
+
+	if (!bench.status) {
+		return EAGAIN;
+	}
+
+	if (!res) {
+		return EINVAL;
+	}
+
+	getrusage(RUSAGE_SELF, &run);
+	clock_gettime(RIN_CLOCK_WALL_COUNTER, &wall);
+
+	res->wall = rin_time_sub(&wall, &bench.wall);
+	res->system = rin_timeval_sub(&run.ru_stime, &bench.runtime.ru_stime);
+	res->user = rin_timeval_sub(&run.ru_utime, &bench.runtime.ru_utime);
+	res->total = rin_timeval_add(&res->system, &res->user);
+
+	bench.status = 0;
+	return 0;
+}
diff --git a/src/time/meson.build b/src/time/meson.build
index 93c1a4d..5a6d9cc 100644
--- a/src/time/meson.build
+++ b/src/time/meson.build
@@ -1,5 +1,6 @@
 if get_option('time')
 	time_filenames = [
+		'benchmark.c',
 		'time.c',
 		'time_private.h',
 	]