concurrent test

whatsmars-common/src/test/java/org/hongxi/java/util/concurrent/FIFOMutex.java

+package org.hongxi.java.util.concurrent;
+
+import java.util.Queue;
+import java.util.concurrent.ConcurrentLinkedQueue;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.locks.LockSupport;
+
+/**
+ * @author shenhongxi 2019/09/01
+ * 公平(先进先出)互斥锁
+ */
+public class FIFOMutex {
+
+    private final AtomicBoolean locked = new AtomicBoolean(false);
+    private final Queue<Thread> waiters = new ConcurrentLinkedQueue<>();
+
+    public void lock() {
+        boolean wasInterrupted = false;
+        Thread current = Thread.currentThread();
+        waiters.add(current);
+
+        // 只有队首的线程可以获取锁
+        while (waiters.peek() != current || !locked.compareAndSet(false, true)) {
+            LockSupport.park(this);
+            if (Thread.interrupted())
+                wasInterrupted = true;
+        }
+
+        waiters.remove();
+        if (wasInterrupted)
+            current.interrupt();
+    }
+
+    public void unlock() {
+        locked.set(false);
+        LockSupport.unpark(waiters.peek());
+    }
+}

whatsmars-common/src/test/java/org/hongxi/java/util/concurrent/LockSupportTest.java

@@ -4,6 +4,7 @@ import java.util.concurrent.locks.LockSupport;
 
 /**
  * @author shenhongxi 2019/8/13
+ * @see FIFOMutex
  */
 public class LockSupportTest {