clean: Use Threads.sleep() utility in SlowTask

Author: vorburger

src/dev/enola/be/task/Task.java

@@ -2,6 +2,8 @@
 
 import static java.util.Objects.requireNonNull;
 
+import dev.enola.common.concurrent.Threads;
+
 import java.time.Duration;
 import java.time.Instant;
 import java.util.Optional;
@@ -30,10 +32,15 @@ protected Task(I input) {
      * <p>This method is called by the {@link TaskExecutor} when the task is executed. It will run
      * in a virtual thread of modern Java. For long-running tasks, please ensure to periodically
      * check for interruption via {@link Thread#isInterrupted()} and terminate early if so, by
-     * throwing {@link InterruptedException}. Please do not, under any circumstances, use the
-     * ancient {@link Thread#yield()} method within implementations of this method (or anywhere
-     * really anymore, nowadays); as it will cause performance degradation by a factor of x100 for
-     * no benefit at all anymore on modern Java, especially on virtual threads.
+     * throwing {@link InterruptedException}.
+     *
+     * <p>Please do not, under any circumstances, use the ancient {@link Thread#yield()} method
+     * within implementations of this method (or anywhere really anymore, nowadays); as it will
+     * cause performance degradation by a factor of x100 for no benefit at all anymore on modern
+     * Java, especially on virtual threads. If you must "simulate work", then please use our {@link
+     * Threads#sleep(Duration)} utility (instead of the JDK {@link Thread#sleep(long)}), which
+     * correctly handles interruption. (But this should really should only be required in tests and
+     * demos, not ever for any real work load.)
      *
      * @return output, never null (use {@link Empty#INSTANCE}; or {@link Optional}, if needed)
      * @throws Exception in case of any failure

src/dev/enola/be/task/demo/LongIncrementingTask.java

@@ -6,6 +6,7 @@
 import dev.enola.be.task.TaskExecutor;
 import dev.enola.be.task.demo.LongIncrementingTask.Input;
 import dev.enola.be.task.demo.LongIncrementingTask.Output;
+import dev.enola.common.concurrent.Threads;
 import dev.enola.common.function.CheckedConsumer;
 import dev.enola.common.log.JulConfigurer;
 

src/dev/enola/be/task/test/SlowTask.java

@@ -1,17 +1,18 @@
 package dev.enola.be.task.test;
 
 import dev.enola.be.task.Task;
+import dev.enola.common.concurrent.Threads;
 
 import java.time.Duration;
 
 public class SlowTask extends Task<String, String> {
 
-    private final long sleepMillis;
+    private final Duration sleep;
     private final Duration timeout;
 
     public SlowTask(String input, long sleepMillis, Duration timeout) {
         super(input);
-        this.sleepMillis = sleepMillis;
+        this.sleep = Duration.ofMillis(sleepMillis);
         this.timeout = timeout;
     }
 
@@ -26,13 +27,7 @@ public Duration timeout() {
 
     @Override
     protected String execute() throws Exception {
-        try {
-            Thread.sleep(sleepMillis);
-            return "Completed: " + input;
-
-        } catch (InterruptedException e) {
-            Thread.currentThread().interrupt();
-            throw e;
-        }
+        Threads.sleep(sleep);
+        return "Completed: " + input;
     }
 }

src/dev/enola/be/task/demo/Threads.java …dev/enola/common/concurrent/Threads.javasrc/dev/enola/be/task/demo/Threads.java renamed to src/dev/enola/common/concurrent/Threads.java src/dev/enola/be/task/demo/Threads.java renamed to src/dev/enola/common/concurrent/Threads.java

@@ -1,8 +1,8 @@
-package dev.enola.be.task.demo;
+package dev.enola.common.concurrent;
 
 import java.time.Duration;
 
-final class Threads {
+public final class Threads {
 
     // from
     // https://github.com/enola-dev/enola/blob/main/java/dev/enola/common/concurrent/Threads.java
@@ -19,8 +19,8 @@ final class Threads {
      * article</a>, or <a
      * href="https://www.yegor256.com/2015/10/20/interrupted-exception.html">yegor256.com Blog
      * Post</a> and <a href="https://github.com/google/guava/issues/1219">Google Guava Issue
-     * #1219</a>, as well as Google Guava's Uninterruptibles.sleepUninterruptibly(Duration) (which does
-     * something different from this).
+     * #1219</a>, as well as Google Guava's Uninterruptibles.sleepUninterruptibly(Duration) (which
+     * does something different from this).
      *
      * @param duration Duration to sleep
      * @throws InterruptedException if interrupted