iaveryanov

public final class Utils {

	private Utils() {
	}
	
	public static void echo(String msg) {
		System.out.println(msg);
	}

	public static void sleep(int millis) {

iaveryanov

Latency Comparison Numbers
--------------------------
L1 cache reference                            0.5 ns
Branch mispredict                             5   ns
L2 cache reference                            7   ns             14x L1 cache
Mutex lock/unlock                            25   ns
Main memory reference                       100   ns             20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy              3,000   ns
Send 1K bytes over 1 Gbps network        10,000   ns    0.01 ms
Read 4K randomly from SSD*              150,000   ns    0.15 ms

iaveryanov

<%@ page language="java" contentType="text/html;charset=UTF-8" %>
<%@ page import="org.apache.log4j.Level" %>
<%@ page import="org.apache.log4j.LogManager" %>
<%@ page import="org.apache.log4j.Logger" %>
<%@ page import="java.util.HashMap" %>
<%@ page import="java.util.Enumeration" %>
<%@ page import="java.util.Set" %>
<%@ page import="java.util.Arrays" %>
<% 
   /* This was originally suggested by Nelz on http://nelz.net/2008/04/08/log4j-runtime-configuration */

iaveryanov

private boolean decTillZero(AtomicLong counter) {
    while (true) {
        long current = counter.get();
        if (current == 0) {
            return false;
        }
        long next = current - 1;
        if (counter.compareAndSet(current, next)) {
            return true;
        }

iaveryanov

    /**
     * Atomically adds the given value to the current value.
     *
     * @param delta the value to add
     * @return the previous value
     */
    public final long getAndAdd(long delta) {
        while (true) {
            long current = get();
            long next = current + delta;

iaveryanov

package ru.inlinetelecom.vn2.util;

import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicLong;

/**
 * вариант с uncontended lock (getAvailableProcessors >= worker_count

iaveryanov

package ru.inlinetelecom.vn2.util;

import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicLong;

/**
 * вариант с uncontended lock (getAvailableProcessors >= worker_count

iaveryanov

package ru;

public interface InterfaceJava8 {

    public static void main(String[] args) {
        System.out.println("Hello from interface! It is java 8!");
    }
}

iaveryanov

package lambda.puzzle;

// source: http://arhipov.blogspot.ru/2014/02/java-8-lambdas-unintentional-puzzle.html
public class Forrest {
    public Runnable wrooom(){
        return () -> { System.out.println("Hello, lambda!"); };
    }

    public static void main(String[] args) {
        Runnable runnable = new Forrest().wrooom();

iaveryanov

package ru;

// origin source: http://arhipov.blogspot.ru/2014/02/java-8-lambdas-unintentional-puzzle.html
// my gist with puzzle https://gist.github.com/iaveryanov/10990181
public class Forrest {
    public Runnable wrooom(){
        return new Runnable() {
            @Override
            public void run() {
                System.out.println("Hello, lambda!");