jonatan-ivanov

package org.example;

import java.lang.management.ManagementFactory;
import java.lang.management.OperatingSystemMXBean;
import java.time.Instant;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.ForkJoinPool;

jonatan-ivanov

// from Jon Schneider
public class GaugeUpdateTrick {
    public static void main(String[] args) {
        AtomicLong lastCalculatedTime = new AtomicLong(0);
        AtomicLong gaugeValue = new AtomicLong(0);
        Gauge.builder("expensive", () -> {
            long curr = System.nanoTime();
            return gaugeValue.updateAndGet(old ->
                    lastCalculatedTime.updateAndGet(ts -> curr - ts > 10_000 ? curr : ts) == curr ? 0L /* new */ : old);
        });

jonatan-ivanov

import java.time.Duration;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.*;
import java.util.concurrent.atomic.AtomicInteger;

public class ForkJoinPoolDemo {
    private static final int SUBMISSIONS = 10;
    private static final int FORKS = 24;
    private static final int PARALLELISM = 5;