\n| \u63a8\u8350\u4f7f\u7528<\/td>\n | \u4e0d\u63a8\u8350<\/td>\n | \u63a8\u8350<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/p>\n\u56db\u3001\u7ebf\u7a0b\u540c\u6b65\u673a\u5236<\/h3>\n<\/p>\n4.1 synchronized\u5173\u952e\u5b57\u8be6\u89e3<\/h4>\n<\/p>\nsynchronized\u662fJava\u4e2d\u6700\u57fa\u672c\u7684\u540c\u6b65\u673a\u5236，\u7528\u4e8e\u89e3\u51b3\u591a\u7ebf\u7a0b\u8bbf\u95ee\u5171\u4eab\u8d44\u6e90\u7684\u7ebf\u7a0b\u5b89\u5168\u95ee\u9898\u3002<\/p>\n<\/p>\n 4.1.1 \u540c\u6b65\u65b9\u6cd5<\/h5>\npublic class SynchronizedMethodDemo {
\n private int counter = 0;<\/p>\n \/\/ \u540c\u6b65\u5b9e\u4f8b\u65b9\u6cd5
\n public synchronized void increment() {
\n counter++;
\n }<\/p>\n \/\/ \u540c\u6b65\u9759\u6001\u65b9\u6cd5
\n public static synchronized void staticMethod() {
\n System.out.println("\u540c\u6b65\u9759\u6001\u65b9\u6cd5");
\n }<\/p>\n public static void main(String[] args) throws InterruptedException {
\n SynchronizedMethodDemo demo = new SynchronizedMethodDemo();<\/p>\n \/\/ \u521b\u5efa\u591a\u4e2a\u7ebf\u7a0b\u5e76\u53d1\u4fee\u6539counter
\n Thread[] threads = new Thread[10];
\n for (int i = 0; i < threads.length; i++) {
\n threads[i] = new Thread(() -> {
\n for (int j = 0; j < 1000; j++) {
\n demo.increment();
\n }
\n });
\n threads[i].start();
\n }<\/p>\n \/\/ \u7b49\u5f85\u6240\u6709\u7ebf\u7a0b\u6267\u884c\u5b8c\u6210
\n for (Thread thread : threads) {
\n thread.join();
\n }<\/p>\n System.out.println("\u6700\u7ec8counter\u503c: " + demo.counter); \/\/ \u5e94\u8be5\u8f93\u51fa10000
\n }
\n}<\/p>\n 4.1.2 \u540c\u6b65\u4ee3\u7801\u5757<\/h5>\npublic class SynchronizedBlockDemo {
\n private int counter = 0;
\n private final Object lock = new Object(); \/\/ \u4e13\u7528\u9501\u5bf9\u8c61<\/p>\n \/\/ \u4f7f\u7528synchronized\u4ee3\u7801\u5757
\n public void increment() {
\n synchronized (lock) { \/\/ \u4f7f\u7528\u4e13\u7528\u9501\u5bf9\u8c61
\n counter++;
\n }
\n }<\/p>\n \/\/ \u540c\u6b65this\u5bf9\u8c61
\n public void incrementThis() {
\n synchronized (this) {
\n counter++;
\n }
\n }<\/p>\n \/\/ \u540c\u6b65Class\u5bf9\u8c61
\n public static void staticBlockMethod() {
\n synchronized (SynchronizedBlockDemo.class) {
\n System.out.println("\u540c\u6b65\u4ee3\u7801\u5757 – Class\u5bf9\u8c61\u9501");
\n }
\n }<\/p>\n public static void main(String[] args) throws InterruptedException {
\n SynchronizedBlockDemo demo = new SynchronizedBlockDemo();<\/p>\n Runnable task = () -> {
\n for (int i = 0; i < 1000; i++) {
\n demo.increment();
\n }
\n };<\/p>\n Thread thread1 = new Thread(task);
\n Thread thread2 = new Thread(task);<\/p>\n thread1.start();
\n thread2.start();<\/p>\n thread1.join();
\n thread2.join();<\/p>\n System.out.println("Counter\u503c: " + demo.counter); \/\/ \u5e94\u8be5\u8f93\u51fa2000
\n }
\n}<\/p>\n 4.2 volatile\u5173\u952e\u5b57<\/h4>\n<\/p>\nvolatile\u5173\u952e\u5b57\u7528\u4e8e\u786e\u4fdd\u53d8\u91cf\u7684\u53ef\u89c1\u6027\u548c\u6709\u5e8f\u6027，\u4f46\u4e0d\u80fd\u4fdd\u8bc1\u539f\u5b50\u6027\u3002<\/p>\n public class VolatileDemo {
\n \/\/ \u4f7f\u7528volatile\u4fdd\u8bc1\u53ef\u89c1\u6027
\n private volatile boolean running = true;
\n private volatile int counter = 0;<\/p>\n public void stop() {
\n running = false;
\n }<\/p>\n public void startThread() {
\n Thread worker = new Thread(() -> {
\n while (running) {
\n counter++;
\n try {
\n Thread.sleep(100);
\n } catch (InterruptedException e) {
\n e.printStackTrace();
\n }
\n }
\n System.out.println("\u7ebf\u7a0b\u5df2\u505c\u6b62，counter\u503c: " + counter);
\n });<\/p>\n worker.start();<\/p>\n \/\/ \u4e3b\u7ebf\u7a0b\u4f11\u77202\u79d2\u540e\u505c\u6b62\u5de5\u4f5c\u7ebf\u7a0b
\n try {
\n Thread.sleep(2000);
\n } catch (InterruptedException e) {
\n e.printStackTrace();
\n }
\n stop();
\n }<\/p>\n public static void main(String[] args) {
\n VolatileDemo demo = new VolatileDemo();
\n demo.startThread();
\n }
\n}<\/p>\n 4.3 \u7ebf\u7a0b\u5b89\u5168\u95ee\u9898\u53ca\u89e3\u51b3\u65b9\u6848<\/h4>\n<\/p>\n4.3.1 \u7ebf\u7a0b\u5b89\u5168\u95ee\u9898\u4ea7\u751f\u539f\u56e0<\/h5>\n<\/p>\n\u539f\u5b50\u6027\u95ee\u9898：\u4e00\u4e2a\u64cd\u4f5c\u4e0d\u80fd\u88ab\u4e2d\u65ad，\u8981\u4e48\u5168\u90e8\u6267\u884c，\u8981\u4e48\u90fd\u4e0d\u6267\u884c<\/li>\n\u53ef\u89c1\u6027\u95ee\u9898：\u4e00\u4e2a\u7ebf\u7a0b\u4fee\u6539\u4e86\u5171\u4eab\u53d8\u91cf\u7684\u503c，\u5176\u4ed6\u7ebf\u7a0b\u4e0d\u80fd\u7acb\u5373\u770b\u5230<\/li>\n\u6709\u5e8f\u6027\u95ee\u9898：\u6307\u4ee4\u91cd\u6392\u5e8f\u5bfc\u81f4\u4ee3\u7801\u6267\u884c\u987a\u5e8f\u4e0e\u9884\u671f\u4e0d\u7b26<\/li>\n4.3.2 \u7ebf\u7a0b\u5b89\u5168\u793a\u4f8b\u4e0e\u89e3\u51b3\u65b9\u6848<\/h5>\npublic class ThreadSafetyDemo {
\n \/\/ \u95ee\u9898\u793a\u4f8b：\u975e\u7ebf\u7a0b\u5b89\u5168\u7684\u8ba1\u6570\u5668
\n private int unsafeCounter = 0;<\/p>\n public void unsafeIncrement() {
\n unsafeCounter++; \/\/ \u975e\u539f\u5b50\u64cd\u4f5c，\u5b58\u5728\u7ebf\u7a0b\u5b89\u5168\u95ee\u9898
\n }<\/p>\n \/\/ \u89e3\u51b3\u65b9\u68481：\u4f7f\u7528synchronized
\n private int syncCounter = 0;<\/p>\n public synchronized void syncIncrement() {
\n syncCounter++;
\n }<\/p>\n \/\/ \u89e3\u51b3\u65b9\u68482：\u4f7f\u7528Atomic\u7c7b（\u63a8\u8350）
\n private AtomicInteger atomicCounter = new AtomicInteger(0);<\/p>\n public void atomicIncrement() {
\n atomicCounter.incrementAndGet();
\n }<\/p>\n \/\/ \u89e3\u51b3\u65b9\u68483：\u4f7f\u7528ReentrantLock
\n private int lockCounter = 0;
\n private ReentrantLock lock = new ReentrantLock();<\/p>\n public void lockIncrement() {
\n lock.lock();
\n try {
\n lockCounter++;
\n } finally {
\n lock.unlock(); \/\/ \u5fc5\u987b\u5728finally\u4e2d\u91ca\u653e\u9501
\n }
\n }<\/p>\n public static void main(String[] args) throws InterruptedException {
\n ThreadSafetyDemo demo = new ThreadSafetyDemo();
\n int threadCount = 100;
\n int incrementPerThread = 1000;<\/p>\n \/\/ \u6d4b\u8bd5\u975e\u7ebf\u7a0b\u5b89\u5168\u7248\u672c
\n testUnsafe(demo, threadCount, incrementPerThread);<\/p>\n \/\/ \u6d4b\u8bd5Atomic\u7248\u672c
\n testAtomic(demo, threadCount, incrementPerThread);
\n }<\/p>\n private static void testUnsafe(ThreadSafetyDemo demo, int threadCount, int incrementPerThread)
\n throws InterruptedException {
\n demo.unsafeCounter = 0;
\n Thread[] threads = new Thread[threadCount];<\/p>\n long startTime = System.currentTimeMillis();
\n for (int i = 0; i < threadCount; i++) {
\n threads[i] = new Thread(() -> {
\n for (int j = 0; j < incrementPerThread; j++) {
\n demo.unsafeIncrement();
\n }
\n });
\n threads[i].start();
\n }<\/p>\n for (Thread thread : threads) {
\n thread.join();
\n }<\/p>\n long endTime = System.currentTimeMillis();
\n System.out.println("\u975e\u7ebf\u7a0b\u5b89\u5168 – \u7ed3\u679c: " + demo.unsafeCounter +
\n ", \u9884\u671f: " + (threadCount * incrementPerThread) +
\n ", \u8017\u65f6: " + (endTime – startTime) + "ms");
\n }<\/p>\n private static void testAtomic(ThreadSafetyDemo demo, int threadCount, int incrementPerThread)
\n throws InterruptedException {
\n demo.atomicCounter.set(0);
\n Thread[] threads = new Thread[threadCount];<\/p>\n long startTime = System.currentTimeMillis();
\n for (int i = 0; i < threadCount; i++) {
\n threads[i] = new Thread(() -> {
\n for (int j = 0; j < incrementPerThread; j++) {
\n demo.atomicIncrement();
\n }
\n });
\n threads[i].start();
\n }<\/p>\n for (Thread thread : threads) {
\n thread.join();
\n }<\/p>\n long endTime = System.currentTimeMillis();
\n System.out.println("Atomic\u7c7b – \u7ed3\u679c: " + demo.atomicCounter.get() +
\n ", \u9884\u671f: " + (threadCount * incrementPerThread) +
\n ", \u8017\u65f6: " + (endTime – startTime) + "ms");
\n }
\n}<\/p>\n \u4e94\u3001\u5e76\u53d1\u5de5\u5177\u7c7b<\/h3>\n<\/p>\n5.1 ThreadPoolExecutor\u7ebf\u7a0b\u6c60<\/h4>\n<\/p>\n\u7ebf\u7a0b\u6c60\u80fd\u591f\u6709\u6548\u7ba1\u7406\u7ebf\u7a0b\u8d44\u6e90，\u63d0\u9ad8\u7a0b\u5e8f\u6027\u80fd\u3002<\/p>\n import java.util.concurrent.*;
\nimport java.util.concurrent.atomic.AtomicInteger;<\/p>\n public class ThreadPoolDemo {
\n private static final AtomicInteger taskNumber = new AtomicInteger(1);<\/p>\n public static void main(String[] args) {
\n \/\/ \u521b\u5efa\u7ebf\u7a0b\u6c60
\n ThreadPoolExecutor executor = new ThreadPoolExecutor(
\n 2, \/\/ \u6838\u5fc3\u7ebf\u7a0b\u6570
\n 4, \/\/ \u6700\u5927\u7ebf\u7a0b\u6570
\n 60L, \/\/ \u7a7a\u95f2\u7ebf\u7a0b\u5b58\u6d3b\u65f6\u95f4
\n TimeUnit.SECONDS, \/\/ \u65f6\u95f4\u5355\u4f4d
\n new ArrayBlockingQueue<>(10), \/\/ \u4efb\u52a1\u961f\u5217
\n Executors.defaultThreadFactory(), \/\/ \u7ebf\u7a0b\u5de5\u5382
\n new ThreadPoolExecutor.CallerRunsPolicy() \/\/ \u62d2\u7edd\u7b56\u7565
\n );<\/p>\n \/\/ \u63d0\u4ea4\u4efb\u52a1
\n for (int i = 0; i < 15; i++) {
\n final int taskId = taskNumber.getAndIncrement();
\n executor.submit(() -> {
\n System.out.println("\u4efb\u52a1" + taskId + "\u5f00\u59cb\u6267\u884c – " +
\n Thread.currentThread().getName());
\n try {
\n Thread.sleep(1000); \/\/ \u6a21\u62df\u4efb\u52a1\u6267\u884c
\n } catch (InterruptedException e) {
\n e.printStackTrace();
\n }
\n System.out.println("\u4efb\u52a1" + taskId + "\u6267\u884c\u5b8c\u6210");
\n return "\u4efb\u52a1" + taskId + "\u7684\u7ed3\u679c";
\n });
\n }<\/p>\n \/\/ \u5173\u95ed\u7ebf\u7a0b\u6c60
\n executor.shutdown();
\n try {
\n \/\/ \u7b49\u5f85\u6240\u6709\u4efb\u52a1\u5b8c\u6210
\n if (!executor.awaitTermination(60, TimeUnit.SECONDS)) {
\n executor.shutdownNow();
\n }
\n } catch (InterruptedException e) {
\n executor.shutdownNow();
\n }
\n }
\n}<\/p>\n 5.2 CountDownLatch\u5012\u8ba1\u65f6\u95e8\u6813<\/h4>\n<\/p>\nCountDownLatch\u7528\u4e8e\u534f\u8c03\u591a\u4e2a\u7ebf\u7a0b\u4e4b\u95f4\u7684\u6267\u884c\u987a\u5e8f\u3002<\/p>\n import java.util.concurrent.*;
\nimport java.util.concurrent.atomic.AtomicInteger;<\/p>\n public class CountDownLatchDemo {
\n public static void main(String[] args) throws InterruptedException {
\n final int THREAD_COUNT = 5;
\n CountDownLatch startLatch = new CountDownLatch(1); \/\/ \u5f00\u59cb\u4fe1\u53f7
\n CountDownLatch endLatch = new CountDownLatch(THREAD_COUNT); \/\/ \u7ed3\u675f\u4fe1\u53f7
\n AtomicInteger resultSum = new AtomicInteger(0);<\/p>\n \/\/ \u521b\u5efa\u5e76\u542f\u52a8\u5de5\u4f5c\u7ebf\u7a0b
\n for (int i = 1; i <= THREAD_COUNT; i++) {
\n final int threadId = i;
\n new Thread(() -> {
\n try {
\n System.out.println("\u7ebf\u7a0b" + threadId + "\u51c6\u5907\u5c31\u7eea，\u7b49\u5f85\u5f00\u59cb\u4fe1\u53f7…");
\n startLatch.await(); \/\/ \u7b49\u5f85\u5f00\u59cb\u4fe1\u53f7<\/p>\n System.out.println("\u7ebf\u7a0b" + threadId + "\u5f00\u59cb\u6267\u884c\u4efb\u52a1");
\n int result = threadId * threadId; \/\/ \u6a21\u62df\u8ba1\u7b97\u4efb\u52a1
\n Thread.sleep(1000); \/\/ \u6a21\u62df\u8017\u65f6\u64cd\u4f5c<\/p>\n resultSum.addAndGet(result);
\n System.out.println("\u7ebf\u7a0b" + threadId + "\u6267\u884c\u5b8c\u6210，\u7ed3\u679c: " + result);<\/p>\n } catch (InterruptedException e) {
\n e.printStackTrace();
\n } finally {
\n endLatch.countDown(); \/\/ \u5b8c\u6210\u540e\u5012\u8ba1\u65f6
\n }
\n }).start();
\n }<\/p>\n \/\/ \u4e3b\u7ebf\u7a0b\u7b49\u5f85\u6240\u6709\u7ebf\u7a0b\u51c6\u5907\u5c31\u7eea
\n Thread.sleep(100);
\n System.out.println("\u4e3b\u7ebf\u7a0b：\u6240\u6709\u5de5\u4f5c\u7ebf\u7a0b\u51c6\u5907\u5c31\u7eea，\u53d1\u9001\u5f00\u59cb\u4fe1\u53f7！");
\n startLatch.countDown(); \/\/ \u53d1\u9001\u5f00\u59cb\u4fe1\u53f7<\/p>\n \/\/ \u7b49\u5f85\u6240\u6709\u5de5\u4f5c\u7ebf\u7a0b\u5b8c\u6210
\n endLatch.await();
\n System.out.println("\u4e3b\u7ebf\u7a0b：\u6240\u6709\u4efb\u52a1\u6267\u884c\u5b8c\u6210，\u603b\u548c: " + resultSum.get());
\n }
\n}<\/p>\n 5.3 \u5176\u4ed6\u5e38\u7528\u5de5\u5177\u7c7b\u7b80\u4ecb<\/h4>\n<\/p>\n\n- Semaphore（\u4fe1\u53f7\u91cf） ：\u63a7\u5236\u540c\u65f6\u8bbf\u95ee\u7279\u5b9a\u8d44\u6e90\u7684\u7ebf\u7a0b\u6570\u91cf<\/li>\n
- CyclicBarrier（\u5faa\u73af\u6805\u680f） ：\u8ba9\u4e00\u7ec4\u7ebf\u7a0b\u5230\u8fbe\u4e00\u4e2a\u5c4f\u969c\u65f6\u88ab\u963b\u585e，\u76f4\u5230\u6700\u540e\u4e00\u4e2a\u7ebf\u7a0b\u5230\u8fbe\u5c4f\u969c\u65f6，\u6240\u6709\u88ab\u5c4f\u969c\u62e6\u622a\u7684\u7ebf\u7a0b\u624d\u4f1a\u7ee7\u7eed\u6267\u884c<\/li>\n
- ConcurrentHashMap：\u7ebf\u7a0b\u5b89\u5168\u7684HashMap\u5b9e\u73b0<\/li>\n
- BlockingQueue：\u963b\u585e\u961f\u5217，\u652f\u6301\u7ebf\u7a0b\u5b89\u5168\u7684\u751f\u4ea7-\u6d88\u8d39\u6a21\u5f0f<\/li>\n<\/ul>\n
\u516d\u3001\u5b9e\u8df5\u5efa\u8bae<\/h3>\n<\/p>\n6.1 \u5e76\u53d1\u7f16\u7a0b\u5e38\u89c1\u95ee\u9898\u53ca\u907f\u5751\u6307\u5357<\/h4>\n<\/p>\n6.1.1 \u6b7b\u9501\u95ee\u9898<\/h5>\npublic class DeadlockDemo {
\n private static final Object lock1 = new Object();
\n private static final Object lock2 = new Object();<\/p>\n public static void main(String[] args) {
\n Thread thread1 = new Thread(() -> {
\n synchronized (lock1) {
\n System.out.println("\u7ebf\u7a0b1\u83b7\u53d6lock1");
\n try { Thread.sleep(100); } catch (InterruptedException e) {}
\n System.out.println("\u7ebf\u7a0b1\u7b49\u5f85lock2");
\n synchronized (lock2) {
\n System.out.println("\u7ebf\u7a0b1\u83b7\u53d6lock2");
\n }
\n }
\n });<\/p>\n Thread thread2 = new Thread(() -> {
\n synchronized (lock2) {
\n System.out.println("\u7ebf\u7a0b2\u83b7\u53d6lock2");
\n try { Thread.sleep(100); } catch (InterruptedException e) {}
\n System.out.println("\u7ebf\u7a0b2\u7b49\u5f85lock1");
\n synchronized (lock1) {
\n System.out.println("\u7ebf\u7a0b2\u83b7\u53d6lock1");
\n }
\n }
\n });<\/p>\n thread1.start();
\n thread2.start();
\n \/\/ \u53ef\u80fd\u4ea7\u751f\u6b7b\u9501
\n }
\n}<\/p>\n \u907f\u5751\u5efa\u8bae：<\/p>\n<\/p>\n \n- \u907f\u514d\u5d4c\u5957\u9501<\/li>\n
- \u6309\u7167\u56fa\u5b9a\u987a\u5e8f\u83b7\u53d6\u9501<\/li>\n
- \u8bbe\u7f6e\u9501\u8d85\u65f6\u65f6\u95f4<\/li>\n
- \u4f7f\u7528tryLock()\u66ff\u4ee3lock()<\/li>\n<\/ul>\n
6.1.2 \u8d44\u6e90\u6cc4\u6f0f<\/h5>\n\/\/ \u9519\u8bef\u793a\u4f8b：\u7ebf\u7a0b\u6c60\u672a\u6b63\u786e\u5173\u95ed
\npublic class ResourceLeakDemo {
\n public static void wrongExample() {
\n ThreadPoolExecutor executor = (ThreadPoolExecutor) Executors.newFixedThreadPool(10);
\n executor.submit(() -> System.out.println("\u4efb\u52a1\u6267\u884c"));
\n \/\/ \u5fd8\u8bb0\u8c03\u7528shutdown()，\u5bfc\u81f4\u7ebf\u7a0b\u6c60\u65e0\u6cd5\u5173\u95ed
\n }<\/p>\n \/\/ \u6b63\u786e\u793a\u4f8b
\n public static void correctExample() {
\n ThreadPoolExecutor executor = (ThreadPoolExecutor) Executors.newFixedThreadPool(10);
\n try {
\n executor.submit(() -> System.out.println("\u4efb\u52a1\u6267\u884c"));
\n } finally {
\n executor.shutdown(); \/\/ \u786e\u4fdd\u7ebf\u7a0b\u6c60\u88ab\u5173\u95ed
\n }
\n }
\n}<\/p>\n 6.2 \u6027\u80fd\u4f18\u5316\u65b9\u5411<\/h4>\n<\/p>\n - \u5408\u7406\u4f7f\u7528\u7ebf\u7a0b\u6c60：\u6839\u636e\u4efb\u52a1\u7c7b\u578b\u9009\u62e9\u5408\u9002\u7684\u7ebf\u7a0b\u6c60\u53c2\u6570<\/li>\n
- \u51cf\u5c11\u9501\u7c92\u5ea6：\u4f7f\u7528\u7ec6\u7c92\u5ea6\u9501\u4ee3\u66ff\u7c97\u7c92\u5ea6\u9501<\/li>\n
- \u4f7f\u7528\u65e0\u9501\u7f16\u7a0b：\u4f18\u5148\u4f7f\u7528Atomic\u7c7b\u548c\u5e76\u53d1\u96c6\u5408<\/li>\n
- \u907f\u514d\u4e0a\u4e0b\u6587\u5207\u6362：\u51cf\u5c11\u7ebf\u7a0b\u521b\u5efa\u548c\u9500\u6bc1\u5f00\u9500<\/li>\n
- \u5408\u7406\u8bbe\u7f6e\u7ebf\u7a0b\u6570\u91cf：\u901a\u5e38\u8bbe\u7f6e\u4e3aCPU\u6838\u5fc3\u6570\u76841-2\u500d<\/li>\n
import java.util.concurrent.*;
\nimport java.util.concurrent.atomic.AtomicLong;<\/p>\n public class PerformanceOptimizationDemo {
\n \/\/ \u6027\u80fd\u5bf9\u6bd4：\u540c\u6b65\u65b9\u5f0f vs \u65e0\u9501\u65b9\u5f0f
\n private long syncCounter = 0;
\n private AtomicLong atomicCounter = new AtomicLong(0);<\/p>\n \/\/ \u540c\u6b65\u65b9\u5f0f
\n public synchronized void syncIncrement() {
\n syncCounter++;
\n }<\/p>\n \/\/ \u65e0\u9501\u65b9\u5f0f
\n public void atomicIncrement() {
\n atomicCounter.incrementAndGet();
\n }<\/p>\n public static void main(String[] args) throws InterruptedException {
\n PerformanceOptimizationDemo demo = new PerformanceOptimizationDemo();
\n int threadCount = 10;
\n int operations = 1000000;<\/p>\n \/\/ \u6d4b\u8bd5synchronized\u6027\u80fd
\n long syncStart = System.currentTimeMillis();
\n testSyncMethod(demo, threadCount, operations);
\n long syncEnd = System.currentTimeMillis();<\/p>\n \/\/ \u6d4b\u8bd5Atomic\u6027\u80fd
\n long atomicStart = System.currentTimeMillis();
\n testAtomicMethod(demo, threadCount, operations);
\n long atomicEnd = System.currentTimeMillis();<\/p>\n System.out.println("synchronized\u8017\u65f6: " + (syncEnd – syncStart) + "ms");
\n System.out.println("Atomic\u8017\u65f6: " + (atomicEnd – atomicStart) + "ms");
\n }<\/p>\n private static void testSyncMethod(PerformanceOptimizationDemo demo,
\n int threadCount, int operations)
\n throws InterruptedException {
\n demo.syncCounter = 0;
\n CountDownLatch latch = new CountDownLatch(threadCount);<\/p>\n for (int i = 0; i < threadCount; i++) {
\n new Thread(() -> {
\n for (int j = 0; j < operations; j++) {
\n demo.syncIncrement();
\n }
\n latch.countDown();
\n }).start();
\n }<\/p>\n latch.await();
\n }<\/p>\n private static void testAtomicMethod(PerformanceOptimizationDemo demo,
\n int threadCount, int operations)
\n throws InterruptedException {
\n demo.atomicCounter.set(0);
\n CountDownLatch latch = new CountDownLatch(threadCount);<\/p>\n for (int i = 0; i < threadCount; i++) {
\n new Thread(() -> {
\n for (int j = 0; j < operations; j++) {
\n demo.atomicIncrement();
\n }
\n latch.countDown();
\n }).start();
\n }<\/p>\n latch.await();
\n }
\n}<\/p>\n \u4e03\u3001\u603b\u7ed3<\/h3>\n<\/p>\nJava\u5e76\u53d1\u7f16\u7a0b\u662f\u6784\u5efa\u9ad8\u6027\u80fd\u5e94\u7528\u7684\u91cd\u8981\u6280\u672f，\u638c\u63e1\u5176\u6838\u5fc3\u6982\u5ff5\u548c\u5b9e\u8df5\u6280\u5de7\u5bf9\u5f00\u53d1\u8005\u81f3\u5173\u91cd\u8981\u3002\u672c\u6587\u4ece\u5e76\u53d1\u7f16\u7a0b\u7684\u57fa\u7840\u6982\u5ff5\u5165\u624b，\u8be6\u7ec6\u4ecb\u7ecd\u4e86Java\u4e2d\u7684\u7ebf\u7a0b\u521b\u5efa\u3001\u540c\u6b65\u673a\u5236\u3001\u5e76\u53d1\u5de5\u5177\u7c7b\u7b49\u6838\u5fc3\u5185\u5bb9，\u5e76\u63d0\u4f9b\u4e86\u4e30\u5bcc\u7684\u4ee3\u7801\u793a\u4f8b\u548c\u5b9e\u8df5\u5efa\u8bae\u3002<\/p>\n<\/p>\n \u6838\u5fc3\u77e5\u8bc6\u70b9\u56de\u987e：<\/p>\n<\/p>\n - \u8fdb\u7a0b\u4e0e\u7ebf\u7a0b：\u7406\u89e3\u8fdb\u7a0b\u548c\u7ebf\u7a0b\u7684\u533a\u522b，\u638c\u63e1\u5e76\u53d1\u4e0e\u5e76\u884c\u7684\u6982\u5ff5<\/li>\n
- \u7ebf\u7a0b\u521b\u5efa：\u4f18\u5148\u4f7f\u7528Runnable\u63a5\u53e3，\u907f\u514d\u7ee7\u627fThread\u7c7b\u7684\u5355\u7ee7\u627f\u9650\u5236<\/li>\n
- \u540c\u6b65\u673a\u5236：\u5408\u7406\u4f7f\u7528synchronized\u548cvolatile，\u7406\u89e3\u5176\u5e95\u5c42\u539f\u7406<\/li>\n
- \u7ebf\u7a0b\u5b89\u5168：\u8bc6\u522b\u7ebf\u7a0b\u5b89\u5168\u95ee\u9898，\u9009\u62e9\u5408\u9002\u7684\u89e3\u51b3\u65b9\u6848（Atomic\u7c7b\u3001Lock\u7b49）<\/li>\n
- \u5e76\u53d1\u5de5\u5177：\u719f\u7ec3\u4f7f\u7528\u7ebf\u7a0b\u6c60\u3001CountDownLatch\u7b49\u5e76\u53d1\u5de5\u5177\u63d0\u9ad8\u7a0b\u5e8f\u6027\u80fd<\/li>\n
- \u6027\u80fd\u4f18\u5316：\u901a\u8fc7\u51cf\u5c11\u9501\u7c92\u5ea6\u3001\u4f7f\u7528\u65e0\u9501\u7f16\u7a0b\u7b49\u65b9\u5f0f\u4f18\u5316\u5e76\u53d1\u6027\u80fd<\/li>\n
Java\u5e76\u53d1\u7f16\u7a0b\u7684\u53d1\u5c55\u5c55\u671b：<\/p>\n<\/p>\n \u968f\u7740Java\u7248\u672c\u7684\u4e0d\u65ad\u66f4\u65b0，\u5e76\u53d1\u7f16\u7a0bAPI\u4e5f\u5728\u6301\u7eed\u4f18\u5316\u3002Java 8\u5f15\u5165\u7684CompletableFuture\u5927\u5927\u7b80\u5316\u4e86\u5f02\u6b65\u7f16\u7a0b，Java 9\u7684\u54cd\u5e94\u5f0f\u7f16\u7a0b\u652f\u6301\u4e3a\u5e76\u53d1\u7f16\u7a0b\u5e26\u6765\u4e86\u65b0\u7684\u53ef\u80fd\u6027\u3002\u672a\u6765，Java\u5e76\u53d1\u7f16\u7a0b\u5c06\u66f4\u52a0\u6ce8\u91cd\u6027\u80fd\u4f18\u5316\u3001\u6613\u7528\u6027\u548c\u53ef\u7ef4\u62a4\u6027，\u5f00\u53d1\u8005\u9700\u8981\u6301\u7eed\u5b66\u4e60\u548c\u638c\u63e1\u65b0\u7684\u5e76\u53d1\u7f16\u7a0b\u6280\u672f\u3002<\/p><\/p>\n","protected":false},"excerpt":{"rendered":" \u4e00\u3001\u5f15\u8a00 \u5728\u5f53\u4eca\u8ba1\u7b97\u673a\u786c\u4ef6\u98de\u901f\u53d1\u5c55\u7684\u80cc\u666f\u4e0b，\u591a\u6838\u5904\u7406\u5668\u5df2\u7ecf\u6210\u4e3a\u6807\u51c6\u914d\u7f6e\u3002\u5982\u4f55\u5145\u5206\u5229\u7528\u591a\u6838CPU\u7684\u8ba1\u7b97\u80fd\u529b，\u63d0\u9ad8\u5e94\u7528\u7a0b\u5e8f\u7684\u6027\u80fd\u548c\u54cd\u5e94\u901f\u5ea6，\u6210\u4e3a\u6bcf\u4e2aJava\u5f00\u53d1\u8005\u5fc5\u987b\u638c\u63e1\u7684\u6838\u5fc3\u6280\u80fd\u3002\u5e76\u53d1\u7f16\u7a0b\u4f5c\u4e3a\u63d0\u5347\u7a0b\u5e8f\u6027\u80fd\u7684\u91cd\u8981\u624b\u6bb5，\u5728Java\u751f\u6001\u7cfb\u7edf\u4e2d\u5360\u636e\u7740\u91cd\u8981\u5730\u4f4d\u3002 Java\u4ece\u8bde\u751f\u4e4b\u521d\u5c31\u5c06\u591a\u7ebf\u7a0b\u652f\u6301\u4f5c\u4e3a\u6838\u5fc3\u7279\u6027\u4e4b\u4e00，\u63d0\u4f9b\u4e86\u4e30\u5bcc\u7684\u5e76\u53d1\u7f16\u7a0bAPI\u548c\u5de5\u5177\u7c7b\u3002\u4ece\u57fa\u7840\u7684Thread\u7c7b\u5230\u9ad8\u7ea7\u7684\u5e76\u53d1\u96c6\u5408，\u4ece\u7b80\u5355\u7684\u540c\u6b65\u673a\u5236\u5230<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[99,190],"topic":[],"class_list":["post-71142","post","type-post","status-publish","format-standard","hentry","category-server","tag-java","tag-190"],"yoast_head":"\n Java\u5e76\u53d1\u7f16\u7a0b\u57fa\u7840\u89e3\u6790 - \u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.wsisp.com\/helps\/71142.html\" \/>\n<meta property=\"og:locale\" content=\"zh_CN\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Java\u5e76\u53d1\u7f16\u7a0b\u57fa\u7840\u89e3\u6790 - \u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3\" \/>\n<meta property=\"og:description\" content=\"\u4e00\u3001\u5f15\u8a00 \u5728\u5f53\u4eca\u8ba1\u7b97\u673a\u786c\u4ef6\u98de\u901f\u53d1\u5c55\u7684\u80cc\u666f\u4e0b，\u591a\u6838\u5904\u7406\u5668\u5df2\u7ecf\u6210\u4e3a\u6807\u51c6\u914d\u7f6e\u3002\u5982\u4f55\u5145\u5206\u5229\u7528\u591a\u6838CPU\u7684\u8ba1\u7b97\u80fd\u529b，\u63d0\u9ad8\u5e94\u7528\u7a0b\u5e8f\u7684\u6027\u80fd\u548c\u54cd\u5e94\u901f\u5ea6，\u6210\u4e3a\u6bcf\u4e2aJava\u5f00\u53d1\u8005\u5fc5\u987b\u638c\u63e1\u7684\u6838\u5fc3\u6280\u80fd\u3002\u5e76\u53d1\u7f16\u7a0b\u4f5c\u4e3a\u63d0\u5347\u7a0b\u5e8f\u6027\u80fd\u7684\u91cd\u8981\u624b\u6bb5，\u5728Java\u751f\u6001\u7cfb\u7edf\u4e2d\u5360\u636e\u7740\u91cd\u8981\u5730\u4f4d\u3002 Java\u4ece\u8bde\u751f\u4e4b\u521d\u5c31\u5c06\u591a\u7ebf\u7a0b\u652f\u6301\u4f5c\u4e3a\u6838\u5fc3\u7279\u6027\u4e4b\u4e00，\u63d0\u4f9b\u4e86\u4e30\u5bcc\u7684\u5e76\u53d1\u7f16\u7a0bAPI\u548c\u5de5\u5177\u7c7b\u3002\u4ece\u57fa\u7840\u7684Thread\u7c7b\u5230\u9ad8\u7ea7\u7684\u5e76\u53d1\u96c6\u5408，\u4ece\u7b80\u5355\u7684\u540c\u6b65\u673a\u5236\u5230\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.wsisp.com\/helps\/71142.html\" \/>\n<meta property=\"og:site_name\" content=\"\u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3\" \/>\n<meta property=\"article:published_time\" content=\"2026-02-03T01:24:41+00:00\" \/>\n<meta name=\"author\" content=\"admin\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"\u4f5c\u8005\" \/>\n\t<meta name=\"twitter:data1\" content=\"admin\" \/>\n\t<meta name=\"twitter:label2\" content=\"\u9884\u8ba1\u9605\u8bfb\u65f6\u95f4\" \/>\n\t<meta name=\"twitter:data2\" content=\"7 \u5206\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\/\/www.wsisp.com\/helps\/71142.html\",\"url\":\"https:\/\/www.wsisp.com\/helps\/71142.html\",\"name\":\"Java\u5e76\u53d1\u7f16\u7a0b\u57fa\u7840\u89e3\u6790 - 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