From 4715706f85a6c4d7f7af564c10cb379e1d880c03 Mon Sep 17 00:00:00 2001
From: Steffen Vogel <post@steffenvogel.de>
Date: Sun, 21 Oct 2018 20:24:32 +0100
Subject: [PATCH] timing: add new function to compare timestamps

---
 common/include/villas/timing.h | 3 +++
 common/lib/timing.c            | 8 ++++++++
 2 files changed, 11 insertions(+)

diff --git a/common/include/villas/timing.h b/common/include/villas/timing.h
index 8a887ec5f..17e0d9d9a 100644
--- a/common/include/villas/timing.h
+++ b/common/include/villas/timing.h
@@ -32,6 +32,9 @@
 extern "C" {
 #endif
 
+/** Compare two timestamps. Return zero if they are equal */
+ssize_t time_cmp(const struct timespec *a, const struct timespec *b);
+
 /** Get delta between two timespec structs */
 struct timespec time_diff(const struct timespec *start, const struct timespec *end);
 
diff --git a/common/lib/timing.c b/common/lib/timing.c
index 9324c895a..980b6e203 100644
--- a/common/lib/timing.c
+++ b/common/lib/timing.c
@@ -84,3 +84,11 @@ double time_delta(const struct timespec *start, const struct timespec *end)
 
 	return time_to_double(&diff);
 }
+
+ssize_t time_cmp(const struct timespec *a, const struct timespec *b)
+{
+	ssize_t sd = a->tv_sec - b->tv_sec;
+	ssize_t nsd = a->tv_nsec - b->tv_nsec;
+
+	return sd != 0 ? sd : nsd;
+}