原子累加器

package com.lx.top;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.atomic.AtomicLong;
import java.util.concurrent.atomic.LongAdder;
import java.util.function.Consumer;
import java.util.function.Supplier;

/**
 * 测试原子累加器
 */
public class Test {
	public static void main(String[] args) {
		// 一段代码被多次执行，jvm会进行优化
		for (int i = 0; i < 5; i++) {
			demo(
					() -> new AtomicLong(0),
					(adder) -> adder.getAndIncrement()
			);
		}
		
		// 一段代码被多次执行，jvm会进行优化
		for (int i = 0; i < 5; i++) {
			demo (
					() -> new LongAdder(),
					adder -> adder.increment()
			);
		}
		
	}
	
	/**
	 * @param1	提供累加器
	 * @param2	执行累加操作
	 */
	private static <T> void demo(Supplier<T> adderSupplier, Consumer<T> action) {
		T adder = adderSupplier.get();
		
		List<Thread> tList = new ArrayList<Thread>();
		// 4个线程，每人累加50万
		for (int i = 0; i < 4; i++) {
			tList.add(new Thread(() -> {
				for (int j = 0; j < 500000; j++) {
					action.accept(adder);
				}
			}));
		}
		
		long start = System.nanoTime();
		
		tList.forEach(t -> t.start());
		tList.forEach(t -> {
			try {
				t.join();
			} catch (Exception e) {
				e.printStackTrace();
			}
		});
		
		long end = System.nanoTime();
		
		System.out.println(adder + " cost: " + (end - start)/1000_000 + "ms");
	}
}

标签：java,int,累加器,原子,util,adder,new,import
来源： https://blog.csdn.net/lenglovexu/article/details/117441084