From 9922b4a419ecad5c9d4ea9e351f5e66e55fad84b Mon Sep 17 00:00:00 2001 From: Håkon Hallingstad Date: Thu, 20 Dec 2018 14:08:42 +0100 Subject: ThreadLocalRandom is recommended over Random in multithreaded environments, try 2 --- .../java/com/yahoo/vespa/service/executor/RunletExecutorImpl.java | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) (limited to 'service-monitor/src') diff --git a/service-monitor/src/main/java/com/yahoo/vespa/service/executor/RunletExecutorImpl.java b/service-monitor/src/main/java/com/yahoo/vespa/service/executor/RunletExecutorImpl.java index 1f647a7fb31..1e2547cc762 100644 --- a/service-monitor/src/main/java/com/yahoo/vespa/service/executor/RunletExecutorImpl.java +++ b/service-monitor/src/main/java/com/yahoo/vespa/service/executor/RunletExecutorImpl.java @@ -4,10 +4,10 @@ package com.yahoo.vespa.service.executor; import com.yahoo.log.LogLevel; import java.time.Duration; -import java.util.Random; import java.util.concurrent.ConcurrentHashMap; import java.util.concurrent.ScheduledFuture; import java.util.concurrent.ScheduledThreadPoolExecutor; +import java.util.concurrent.ThreadLocalRandom; import java.util.concurrent.TimeUnit; import java.util.concurrent.atomic.AtomicInteger; import java.util.logging.Logger; @@ -18,9 +18,6 @@ import java.util.logging.Logger; public class RunletExecutorImpl implements RunletExecutor { private static Logger logger = Logger.getLogger(RunletExecutorImpl.class.getName()); - // About 'static': Javadoc says "Instances of java.util.Random are threadsafe." - private static final Random random = new Random(); - private final AtomicInteger executionId = new AtomicInteger(0); private final ConcurrentHashMap cancellables = new ConcurrentHashMap<>(); private final ScheduledThreadPoolExecutor executor; @@ -30,7 +27,7 @@ public class RunletExecutorImpl implements RunletExecutor { } public Cancellable scheduleWithFixedDelay(Runlet runlet, Duration delay) { - Duration initialDelay = Duration.ofMillis((long) random.nextInt((int) delay.toMillis())); + Duration initialDelay = Duration.ofMillis((long) ThreadLocalRandom.current().nextInt((int) delay.toMillis())); CancellableImpl cancellable = new CancellableImpl(runlet); ScheduledFuture future = executor.scheduleWithFixedDelay(cancellable, initialDelay.toMillis(), delay.toMillis(), TimeUnit.MILLISECONDS); cancellable.setPeriodicExecutionCancellationCallback(() -> future.cancel(false)); -- cgit v1.2.3