List
package com.mmall.concurrency.example.commonUnsafe; import com.mmall.concurrency.annoations.NotThreadSafe; import lombok.extern.slf4j.Slf4j; import java.util.ArrayList; import java.util.List; import java.util.concurrent.CountDownLatch; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import java.util.concurrent.Semaphore; @Slf4j @NotThreadSafe public class ArrayListExample { // 请求总数 public static int clientTotal = 5000; // 同时并发执行的线程数 public static int threadTotal = 200; private static List<Integer> list = new ArrayList<>(); public static void main(String[] args) throws Exception { ExecutorService executorService = Executors.newCachedThreadPool(); final Semaphore semaphore = new Semaphore(threadTotal); final CountDownLatch countDownLatch = new CountDownLatch(clientTotal); for (int i = 0; i < clientTotal; i++) { final int count = i; executorService.execute(() -> { try { semaphore.acquire(); update(count); semaphore.release(); } catch (Exception e) { log.error("exception", e); } countDownLatch.countDown(); }); } countDownLatch.await(); executorService.shutdown(); log.info("size:{}", list.size()); } private static void update(int i) { list.add(i); } } // 输出 size:4988
解决方案一（同步容器：Vector）
package com.mmall.concurrency.example.syncContainer; import com.mmall.concurrency.annoations.ThreadSafe; import lombok.extern.slf4j.Slf4j; import java.util.List; import java.util.Vector; import java.util.concurrent.CountDownLatch; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import java.util.concurrent.Semaphore; @Slf4j @ThreadSafe public class VectorExample1 { // 请求总数 public static int clientTotal = 5000; // 同时并发执行的线程数 public static int threadTotal = 200; private static List<Integer> list = new Vector<>(); public static void main(String[] args) throws Exception { ExecutorService executorService = Executors.newCachedThreadPool(); final Semaphore semaphore = new Semaphore(threadTotal); final CountDownLatch countDownLatch = new CountDownLatch(clientTotal); for (int i = 0; i < clientTotal; i++) { final int count = i; executorService.execute(() -> { try { semaphore.acquire(); update(count); semaphore.release(); } catch (Exception e) { log.error("exception", e); } countDownLatch.countDown(); }); } countDownLatch.await(); executorService.shutdown(); log.info("size:{}", list.size()); } private static void update(int i) { list.add(i); } } // 输出 size:5000
解决方案二（同步容器：synchronizedList）
package com.mmall.concurrency.example.syncContainer; import com.google.common.collect.Lists; import com.mmall.concurrency.annoations.ThreadSafe; import lombok.extern.slf4j.Slf4j; import java.util.Collections; import java.util.List; import java.util.Vector; import java.util.concurrent.CountDownLatch; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import java.util.concurrent.Semaphore; @Slf4j @ThreadSafe public class CollectionsExample1 { // 请求总数 public static int clientTotal = 5000; // 同时并发执行的线程数 public static int threadTotal = 200; private static List<Integer> list = Collections.synchronizedList(Lists.newArrayList()); public static void main(String[] args) throws Exception { ExecutorService executorService = Executors.newCachedThreadPool(); final Semaphore semaphore = new Semaphore(threadTotal); final CountDownLatch countDownLatch = new CountDownLatch(clientTotal); for (int i = 0; i < clientTotal; i++) { final int count = i; executorService.execute(() -> { try { semaphore.acquire(); update(count); semaphore.release(); } catch (Exception e) { log.error("exception", e); } countDownLatch.countDown(); }); } countDownLatch.await(); executorService.shutdown(); log.info("size:{}", list.size()); } private static void update(int i) { list.add(i); } } // 输出 szie:5000
