Improve readability

3 files changed, 31 insertions, 26 deletions

diff --git a/vespajlib/src/main/java/com/yahoo/concurrent/maintenance/Maintainer.java b/vespajlib/src/main/java/com/yahoo/concurrent/maintenance/Maintainer.java
index fdb73e405c0..7fa591a88ba 100644
--- a/vespajlib/src/main/java/com/yahoo/concurrent/maintenance/Maintainer.java
+++ b/vespajlib/src/main/java/com/yahoo/concurrent/maintenance/Maintainer.java
@@ -48,9 +48,7 @@ public abstract class Maintainer implements Runnable {
         this.ignoreCollision = ignoreCollision;
         this.clock = clock;
         this.successFactorBaseline = successFactorBaseline;
-        var startedAt = clock.instant();
-        Objects.requireNonNull(clusterHostnames);
-        Duration initialDelay = staggeredDelay(interval, startedAt, HostName.getLocalhost(), clusterHostnames)
+        Duration initialDelay = staggeredDelay(interval, HostName.getLocalhost(), clusterHostnames)
                                 .plus(Duration.ofSeconds(30)); // Let the system stabilize before maintenance
         service = new ScheduledThreadPoolExecutor(1, r -> new Thread(r, name() + "-worker"));
         service.scheduleAtFixedRate(this, initialDelay.toMillis(), interval.toMillis(), TimeUnit.MILLISECONDS);
@@ -149,11 +147,12 @@ public abstract class Maintainer implements Runnable {
     }
 
     /** Returns the initial delay of this calculated from cluster index of the hostname of this node, and the maintainer name. */
-    Duration staggeredDelay(Duration interval, Instant now, String hostname, List<String> clusterHostnames) {
+    Duration staggeredDelay(Duration interval, String hostname, List<String> clusterHostnames) {
         Objects.requireNonNull(clusterHostnames);
         if ( ! clusterHostnames.contains(hostname))
             return interval;
 
+        Instant now = clock.instant();
         long nodeOffset = clusterHostnames.indexOf(hostname) * interval.toMillis() / clusterHostnames.size();
         long maintainerOffset = getClass().getName().hashCode() % interval.toMillis();
         long totalOffset = nodeOffset + maintainerOffset;
diff --git a/vespajlib/src/test/java/com/yahoo/concurrent/maintenance/MaintainerTest.java b/vespajlib/src/test/java/com/yahoo/concurrent/maintenance/MaintainerTest.java
index 01e23c81971..a65af1e264e 100644
--- a/vespajlib/src/test/java/com/yahoo/concurrent/maintenance/MaintainerTest.java
+++ b/vespajlib/src/test/java/com/yahoo/concurrent/maintenance/MaintainerTest.java
@@ -2,6 +2,7 @@
 package com.yahoo.concurrent.maintenance;
 
 import com.yahoo.concurrent.UncheckedTimeoutException;
+import com.yahoo.test.ManualClock;
 import org.junit.Test;
 
 import java.time.Duration;
@@ -23,29 +24,30 @@ public class MaintainerTest {
     public void staggering() {
         List<String> cluster = List.of("cfg1", "cfg2", "cfg3");
         Duration interval = Duration.ofMillis(300);
-        Instant now = Instant.ofEpochMilli(1000);
+        ManualClock clock = new ManualClock(Instant.ofEpochMilli(1000));
+
         // ∠( ᐛ 」∠)＿
-        class MaintainerWithBestHashE extends TestMaintainer { MaintainerWithBestHashE() { super(null, jobControl, new TestJobMetrics()); } }
-        class MaintainerWithBestHashF extends TestMaintainer { MaintainerWithBestHashF() { super(null, jobControl, new TestJobMetrics()); } }
-        class MaintainerWithBestHashG extends TestMaintainer { MaintainerWithBestHashG() { super(null, jobControl, new TestJobMetrics()); } }
-        Maintainer maintainer = new MaintainerWithBestHashF();
-        assertEquals(200, maintainer.staggeredDelay(interval, now, "cfg1", cluster).toMillis());
-        assertEquals(299, new MaintainerWithBestHashE().staggeredDelay(interval, now, "cfg2", cluster).toMillis());
-        assertEquals(0, maintainer.staggeredDelay(interval, now, "cfg2", cluster).toMillis());
-        assertEquals(1, new MaintainerWithBestHashG().staggeredDelay(interval, now, "cfg2", cluster).toMillis());
-        assertEquals(100, maintainer.staggeredDelay(interval, now, "cfg3", cluster).toMillis());
-
-        now = Instant.ofEpochMilli(1001);
-        assertEquals(199, maintainer.staggeredDelay(interval, now, "cfg1", cluster).toMillis());
-        assertEquals(299, maintainer.staggeredDelay(interval, now, "cfg2", cluster).toMillis());
-        assertEquals(99, maintainer.staggeredDelay(interval, now, "cfg3", cluster).toMillis());
-
-        now = Instant.ofEpochMilli(1101);
-        assertEquals(99, maintainer.staggeredDelay(interval, now, "cfg1", cluster).toMillis());
-        assertEquals(199, maintainer.staggeredDelay(interval, now, "cfg2", cluster).toMillis());
-        assertEquals(299, maintainer.staggeredDelay(interval, now, "cfg3", cluster).toMillis());
-
-        assertEquals(300, maintainer.staggeredDelay(interval, now, "cfg0", cluster).toMillis());
+        class MaintainerWithBestHashE extends TestMaintainer { MaintainerWithBestHashE() { super(jobControl, new TestJobMetrics(), clock); } }
+        class MaintainerWithBestHashF extends TestMaintainer { MaintainerWithBestHashF() { super(jobControl, new TestJobMetrics(), clock); } }
+        class MaintainerWithBestHashG extends TestMaintainer { MaintainerWithBestHashG() { super(jobControl, new TestJobMetrics(), clock); } }
+
+        assertEquals(200, new MaintainerWithBestHashF().staggeredDelay(interval, "cfg1", cluster).toMillis());
+        assertEquals(299, new MaintainerWithBestHashE().staggeredDelay(interval, "cfg2", cluster).toMillis());
+        assertEquals(  0, new MaintainerWithBestHashF().staggeredDelay(interval, "cfg2", cluster).toMillis());
+        assertEquals(  1, new MaintainerWithBestHashG().staggeredDelay(interval, "cfg2", cluster).toMillis());
+        assertEquals(100, new MaintainerWithBestHashF().staggeredDelay(interval, "cfg3", cluster).toMillis());
+
+        clock.advance(Duration.ofMillis(1));
+        assertEquals(199, new MaintainerWithBestHashF().staggeredDelay(interval, "cfg1", cluster).toMillis());
+        assertEquals(299, new MaintainerWithBestHashF().staggeredDelay(interval, "cfg2", cluster).toMillis());
+        assertEquals( 99, new MaintainerWithBestHashF().staggeredDelay(interval, "cfg3", cluster).toMillis());
+
+        clock.advance(Duration.ofMillis(100));
+        assertEquals( 99, new MaintainerWithBestHashF().staggeredDelay(interval, "cfg1", cluster).toMillis());
+        assertEquals(199, new MaintainerWithBestHashF().staggeredDelay(interval, "cfg2", cluster).toMillis());
+        assertEquals(299, new MaintainerWithBestHashF().staggeredDelay(interval, "cfg3", cluster).toMillis());
+
+        assertEquals(300, new MaintainerWithBestHashF().staggeredDelay(interval, "cfg0", cluster).toMillis());
     }
 
     @Test
diff --git a/vespajlib/src/test/java/com/yahoo/concurrent/maintenance/TestMaintainer.java b/vespajlib/src/test/java/com/yahoo/concurrent/maintenance/TestMaintainer.java
index 9e994312738..8c7ca1e18db 100644
--- a/vespajlib/src/test/java/com/yahoo/concurrent/maintenance/TestMaintainer.java
+++ b/vespajlib/src/test/java/com/yahoo/concurrent/maintenance/TestMaintainer.java
@@ -15,6 +15,10 @@ class TestMaintainer extends Maintainer {
     private double success = 1.0;
     private RuntimeException exceptionToThrow = null;
 
+    TestMaintainer(JobControl jobControl, JobMetrics jobMetrics, Clock clock) {
+        super(null, Duration.ofDays(1), clock, jobControl, jobMetrics, List.of(), false);
+    }
+
     TestMaintainer(String name, JobControl jobControl, JobMetrics jobMetrics) {
         super(name, Duration.ofDays(1), Clock.systemUTC(), jobControl, jobMetrics, List.of(), false);
     }