From 90a89e0055b6bfb91f1c63d8194bd966a1068b9c Mon Sep 17 00:00:00 2001
From: Winston Chang <winston@stdout.org>
Date: Mon, 28 Jun 2021 15:13:24 -0500
Subject: [PATCH] Use monotonically-increasing time stamps. Fixes #150

---
 src/timestamp_unix.cpp | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/timestamp_unix.cpp b/src/timestamp_unix.cpp
index 28f0ac86..ab4efdec 100644
--- a/src/timestamp_unix.cpp
+++ b/src/timestamp_unix.cpp
@@ -5,9 +5,9 @@
 #include "timeconv.h"
 
 void get_current_time(timespec *ts) {
-  timeval tv;
-  gettimeofday(&tv, NULL);
-  *ts = timevalToTimespec(tv);
+  // CLOCK_MONOTONIC ensures that we never get timestamps that go backward in
+  // time due to clock adjustment. https://github.com/r-lib/later/issues/150
+  clock_gettime(CLOCK_MONOTONIC, ts);
 }
 
 class TimestampImplPosix : public TimestampImpl {