add lock fair testcase

src/test/java/com/alibaba/druid/bvt/pool/LockFairTest.java

@@ -1,5 +1,6 @@
 package com.alibaba.druid.bvt.pool;
 
+import java.sql.Connection;
 import java.util.concurrent.locks.ReentrantLock;
 
 import junit.framework.Assert;
@@ -11,19 +12,50 @@ import com.alibaba.druid.util.JdbcUtils;
 public class LockFairTest extends TestCase {
 
     private DruidDataSource dataSource;
-    
+
     protected void setUp() throws Exception {
         dataSource = new DruidDataSource();
+        dataSource.setUrl("jdbc:mock:xx");
     }
-    
+
     protected void tearDown() throws Exception {
         JdbcUtils.close(dataSource);
     }
 
     public void test_fair() throws Exception {
-        Assert.assertEquals(false, ((ReentrantLock)dataSource.getLock()).isFair());
+        Assert.assertEquals(false, ((ReentrantLock) dataSource.getLock()).isFair());
         dataSource.setMaxWait(100);
+
+        Assert.assertEquals(true, ((ReentrantLock) dataSource.getLock()).isFair());
+        {
+            Connection conn = dataSource.getConnection();
+            conn.close();
+        }
+        dataSource.setMaxWait(110);
+
+        Assert.assertEquals(true, ((ReentrantLock) dataSource.getLock()).isFair());
+        {
+            Connection conn = dataSource.getConnection();
+            conn.close();
+        }
         
-        Assert.assertEquals(true, ((ReentrantLock)dataSource.getLock()).isFair());
+        dataSource.setMaxWait(0);
+
+        Assert.assertEquals(true, ((ReentrantLock) dataSource.getLock()).isFair());
+        {
+            Connection conn = dataSource.getConnection();
+            conn.close();
+        }
+    }
+
+    public void test_fair_1() throws Exception {
+
+        Connection conn = dataSource.getConnection();
+        conn.close();
+
+        Assert.assertEquals(false, ((ReentrantLock) dataSource.getLock()).isFair());
+        dataSource.setMaxWait(100);
+
+        Assert.assertEquals(false, ((ReentrantLock) dataSource.getLock()).isFair());
     }
 }