2 files changed, 25 insertions, 8 deletions
diff --git a/metrics/src/vespa/metrics/metrictimer.cpp b/metrics/src/vespa/metrics/metrictimer.cpp
index 84d4844104d..a3b0f215d58 100644
--- a/metrics/src/vespa/metrics/metrictimer.cpp
+++ b/metrics/src/vespa/metrics/metrictimer.cpp
@@ -3,13 +3,18 @@
 
 namespace metrics {
 
-MetricTimer::MetricTimer()
+MetricTimer::MetricTimer() noexcept
+    : _startTime(std::chrono::steady_clock::now())
 {
     // Amusingly enough, steady_clock was not actually steady by default on
     // GCC < 4.8.1, so add a bit of compile-time paranoia just to make sure.
     static_assert(std::chrono::steady_clock::is_steady,
                   "Old/broken STL implementation; steady_clock not steady");
-    _startTime = std::chrono::steady_clock::now();
+}
+
+MetricTimer::MetricTimer(std::chrono::steady_clock::time_point start_time) noexcept
+    : _startTime(start_time)
+{
 }
 
 } // metrics
diff --git a/metrics/src/vespa/metrics/metrictimer.h b/metrics/src/vespa/metrics/metrictimer.h
index 8a338432362..133cd819489 100644
--- a/metrics/src/vespa/metrics/metrictimer.h
+++ b/metrics/src/vespa/metrics/metrictimer.h
@@ -15,7 +15,19 @@ namespace metrics {
 
 class MetricTimer {
 public:
-    MetricTimer();
+    // Start time point set by system steady clock
+    MetricTimer() noexcept;
+    // Start time point explicitly given
+    explicit MetricTimer(std::chrono::steady_clock::time_point start_time) noexcept;
+
+    template<typename AvgVal, typename TotVal, bool SumOnAdd>
+    AvgVal stop(std::chrono::steady_clock::time_point now, ValueMetric<AvgVal, TotVal, SumOnAdd>& metric) const {
+        const auto delta = now - _startTime;
+        using ToDuration = std::chrono::duration<AvgVal, std::milli>;
+        const auto deltaMs(std::chrono::duration_cast<ToDuration>(delta).count());
+        metric.addValue(deltaMs);
+        return deltaMs;
+    }
 
     /**
      * Adds ms passed since this timer was constructed to given value metric.
@@ -26,11 +38,11 @@ public:
      */
     template<typename AvgVal, typename TotVal, bool SumOnAdd>
     AvgVal stop(ValueMetric<AvgVal, TotVal, SumOnAdd>& metric) const {
-        const auto delta = std::chrono::steady_clock::now() - _startTime;
-        using ToDuration = std::chrono::duration<AvgVal, std::milli>;
-        const auto deltaMs(std::chrono::duration_cast<ToDuration>(delta).count());
-        metric.addValue(deltaMs);
-        return deltaMs;
+        return stop(std::chrono::steady_clock::now(), metric);
+    }
+
+    [[nodiscard]] std::chrono::steady_clock::time_point start_time() const noexcept {
+        return _startTime;
     }
 
 private: