ReadWriteLockDemo

Author: ZHENFENG13

src/chapter3/ReadWriteLockDemo.java

@@ -0,0 +1,77 @@
+package chapter3;
+
+import java.util.Random;
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReentrantLock;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
+
+/**
+ * Created by 13 on 2017/5/5.
+ */
+public class ReadWriteLockDemo {
+    private static Lock lock = new ReentrantLock();
+    private static ReentrantReadWriteLock reentrantReadWriteLock = new ReentrantReadWriteLock();
+    private static Lock readLock = reentrantReadWriteLock.readLock();
+    private static Lock writeLock = reentrantReadWriteLock.writeLock();
+    private int value;
+
+    public Object handleRead(Lock lock) throws InterruptedException {
+        try {
+            lock.lock();
+            Thread.sleep(1000);//模拟读操作
+            System.out.println("读操作:" + value);
+            return value;
+        } finally {
+            lock.unlock();
+        }
+    }
+
+    public void handleWrite(Lock lock, int index) throws InterruptedException {
+        try {
+            lock.lock();
+            Thread.sleep(1000);//模拟写操作
+            System.out.println("写操作:" + value);
+            value = index;
+        } finally {
+            lock.unlock();
+        }
+    }
+
+    public static void main(String args[]) {
+        final ReadWriteLockDemo demo = new ReadWriteLockDemo();
+
+        Runnable readRunnable = new Runnable() {
+            @Override
+            public void run() {
+                //分别使用两种锁来运行,性能差别很直观的就体现出来,使用读写锁后读操作可以并行,节省了大量时间
+                try {
+                    demo.handleRead(readLock);
+                    //demo.handleRead(lock);
+                } catch (InterruptedException e) {
+                    e.printStackTrace();
+                }
+
+            }
+        };
+
+        Runnable writeRunnable = new Runnable() {
+            @Override
+            public void run() {
+                //分别使用两种锁来运行,性能差别很直观的就体现出来
+                try {
+                    demo.handleWrite(writeLock, new Random().nextInt(100));
+                    //demo.handleWrite(lock, new Random().nextInt(100));
+                } catch (InterruptedException e) {
+                    e.printStackTrace();
+                }
+
+            }
+        };
+        for (int i = 0; i < 18; i++) {
+            new Thread(readRunnable).start();
+        }
+        for (int i = 18; i < 20; i++) {
+            new Thread(writeRunnable).start();
+        }
+    }
+}