package com.winterbe.java8.samples.concurrent;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Semaphore;
import java.util.concurrent.TimeUnit;
import java.util.stream.IntStream;
/**
* @author Benjamin Winterberg
*/
public class Semaphore1 {
private static final int NUM_INCREMENTS = 10000;
private static Semaphore semaphore = new Semaphore(1);
private static int count = 0;
public static void main(String[] args) {
testIncrement();
}
private static void testIncrement() {
ExecutorService executor = Executors.newFixedThreadPool(2);
IntStream.range(0, NUM_INCREMENTS)
.forEach(i -> executor.submit(Semaphore1::increment));
ConcurrentUtils.stop(executor);
System.out.println("Increment: " + count);
}
private static void increment() {
boolean permit = false;
try {
permit = semaphore.tryAcquire(5, TimeUnit.SECONDS);
count++;
}
catch (InterruptedException e) {
throw new RuntimeException("could not increment");
}
finally {
if (permit) {
semaphore.release();
}
}
}
}