fix: Remove Thread.yield()

Author: vorburger

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

@@ -27,6 +27,14 @@ protected Task(I input) {
     /**
      * The main logic of the task.
      *
+     * <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.
+     *
      * @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

@@ -30,7 +30,7 @@ public LongIncrementingTask(Input input, CheckedConsumer<Long, IOException> prog
     protected Output execute() throws Exception {
         for (long i = 0; i < input.max; i++) {
             progressConsumer.accept(i);
-            Thread.yield();
+            // Do *NOT* Thread.yield(); that makes it really horribly slow, by like a factor x100!
             if (Thread.currentThread().isInterrupted())
                 throw new InterruptedException("Task was interrupted");
             Threads.sleep(input.sleep);
@@ -44,7 +44,7 @@ protected Output execute() throws Exception {
     private static void simpleLoop(long max, Duration sleep) throws InterruptedException {
         var start = Instant.now();
         for (long i = 0; i < max; i++) {
-            // Thread.yield();
+            // Do *NOT* Thread.yield(); that makes it really horribly slow, by like a factor x100!
             Threads.sleep(sleep);
         }
         var duration = Duration.between(start, Instant.now());