2 files changed, 13 insertions, 24 deletions
diff --git a/vespajlib/src/main/java/com/yahoo/concurrent/SystemTimer.java b/vespajlib/src/main/java/com/yahoo/concurrent/SystemTimer.java
index 8111d52a10f..c2fca806a85 100644
--- a/vespajlib/src/main/java/com/yahoo/concurrent/SystemTimer.java
+++ b/vespajlib/src/main/java/com/yahoo/concurrent/SystemTimer.java
@@ -42,21 +42,18 @@ public enum SystemTimer implements Timer {
 
     SystemTimer() {
         long napTime = adjustTimeoutByDetectedHz(Duration.ofMillis(1)).toMillis();
-        millis = TimeUnit.NANOSECONDS.toMillis(System.nanoTime());
-        Thread thread = new Thread() {
-
-            @Override
-            public void run() {
-                while (true) {
-                    millis = TimeUnit.NANOSECONDS.toMillis(System.nanoTime());
-                    try {
-                        Thread.sleep(napTime);
-                    } catch (InterruptedException e) {
-                        break;
-                    }
+        long creationNanos = System.nanoTime();
+        millis = TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - creationNanos);
+        Thread thread = new Thread(() -> {
+            while (true) {
+                millis = TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - creationNanos);
+                try {
+                    Thread.sleep(napTime);
+                } catch (InterruptedException e) {
+                    break;
                 }
             }
-        };
+        });
         thread.setDaemon(true);
         thread.setName("vespa-system-timer");
         thread.start();
diff --git a/vespajlib/src/main/java/com/yahoo/concurrent/Timer.java b/vespajlib/src/main/java/com/yahoo/concurrent/Timer.java
index c41c762c989..9328039aae6 100644
--- a/vespajlib/src/main/java/com/yahoo/concurrent/Timer.java
+++ b/vespajlib/src/main/java/com/yahoo/concurrent/Timer.java
@@ -20,16 +20,8 @@ public interface Timer {
      * @return The current value of the timer, in milliseconds.
      */
     long milliTime();
-    Timer monotonic = () -> TimeUnit.NANOSECONDS.toMillis(System.nanoTime());
-    static Timer wrap(Clock original) {
-        return new Timer() {
-            private final Clock clock = original;
-
-            @Override
-            public long milliTime() {
-                return clock.millis();
-            }
-        }; }
-
+    long creationNanos = System.nanoTime(); // Avoid monotonic timer overflow for the first 146 years of JVM uptime.
+    Timer monotonic = () -> TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - creationNanos);
+    static Timer wrap(Clock original) { return original::millis; }
     default Instant instant() { return Instant.ofEpochMilli(milliTime()); }
 }