wildfire chat server source initial submit

broker/src/main/java/win/liyufan/im/SpinLock.java

@@ -0,0 +1,21 @@
+package win.liyufan.im;
+
+import java.util.concurrent.atomic.AtomicReference;
+
+public class SpinLock {
+    //java中原子（CAS）操作
+    AtomicReference<Thread> owner = new AtomicReference<>();//持有自旋锁的线程对象
+    private int count;
+    public void lock() {
+        Thread cur = Thread.currentThread();
+        //lock函数将owner设置为当前线程，并且预测原来的值为空。unlock函数将owner设置为null，并且预测值为当前线程。当有第二个线程调用lock操作时由于owner值不为空，导致循环
+
+        //一直被执行，直至第一个线程调用unlock函数将owner设置为null，第二个线程才能进入临界区。
+        while (!owner.compareAndSet(null, cur)){
+        }
+    }
+    public void unLock() {
+        Thread cur = Thread.currentThread();
+        owner.compareAndSet(cur, null);
+    }
+}