From 899be14b8a69f7e5911b77d5a109309a832a2515 Mon Sep 17 00:00:00 2001
From: wenshao <szujobs@hotmail.com>
Date: Fri, 17 Aug 2012 07:53:09 +0800
Subject: [PATCH] add dynamic change maxActive support

---
 .../alibaba/druid/pool/DruidDataSource.java   | 10 ++++-
 .../druid/bvt/pool/MaxActiveChangeTest.java   | 45 +++++++++++++++----
 2 files changed, 45 insertions(+), 10 deletions(-)

diff --git a/src/main/java/com/alibaba/druid/pool/DruidDataSource.java b/src/main/java/com/alibaba/druid/pool/DruidDataSource.java
index f50e74fe50..b752155e6c 100644
--- a/src/main/java/com/alibaba/druid/pool/DruidDataSource.java
+++ b/src/main/java/com/alibaba/druid/pool/DruidDataSource.java
@@ -252,6 +252,14 @@ public class DruidDataSource extends DruidAbstractDataSource implements DruidDat
         if (this.maxActive == maxActive) {
             return;
         }
+        
+        if (maxActive < this.minIdle) {
+            throw new IllegalArgumentException("maxActive less than minIdle, " + maxActive + " < " + this.minIdle);
+        }
+        
+        if (maxActive == 0) {
+            throw new IllegalArgumentException("maxActive can't not set zero");
+        }
 
         if (!inited) {
             this.maxActive = maxActive;
@@ -259,7 +267,7 @@ public class DruidDataSource extends DruidAbstractDataSource implements DruidDat
         }
 
         if (LOG.isInfoEnabled()) {
-            LOG.info("set maxActive " + this.maxActive + " -> " + maxActive);
+            LOG.info("maxActive modified : " + this.maxActive + " -> " + maxActive);
         }
 
         lock.lock();
diff --git a/src/test/java/com/alibaba/druid/bvt/pool/MaxActiveChangeTest.java b/src/test/java/com/alibaba/druid/bvt/pool/MaxActiveChangeTest.java
index 9145a1a2d8..a7eef8e904 100644
--- a/src/test/java/com/alibaba/druid/bvt/pool/MaxActiveChangeTest.java
+++ b/src/test/java/com/alibaba/druid/bvt/pool/MaxActiveChangeTest.java
@@ -45,35 +45,62 @@ public class MaxActiveChangeTest extends TestCase {
             Assert.assertEquals(3, connect(4));
             Assert.assertEquals(3, dataSource.getPoolingCount());
         }
-        
+
         dataSource.setMaxActive(4);
-        
+
         for (int i = 0; i < 10; ++i) {
             Assert.assertEquals(4, connect(4));
             Assert.assertEquals(4, dataSource.getPoolingCount());
         }
-        
+
         dataSource.shrink();
         Assert.assertEquals(1, dataSource.getPoolingCount());
-        
+
         for (int i = 0; i < 10; ++i) {
             Assert.assertEquals(4, connect(4));
             Assert.assertEquals(4, dataSource.getPoolingCount());
         }
-        
+
         Assert.assertEquals(4, dataSource.getPoolingCount());
         dataSource.setMaxActive(3);
-        
+
         Assert.assertEquals(4, dataSource.getPoolingCount());
-        
+
         dataSource.shrink();
         Assert.assertEquals(1, dataSource.getPoolingCount());
-        
+
         // 确保收缩之后不会再长上去
         for (int i = 0; i < 10; ++i) {
             Assert.assertEquals(3, connect(4));
             Assert.assertEquals(3, dataSource.getPoolingCount());
         }
+
+        dataSource.setMaxActive(2);
+        dataSource.shrink();
+        Assert.assertEquals(1, dataSource.getPoolingCount());
+
+        for (int i = 0; i < 10; ++i) {
+            Assert.assertEquals(2, connect(3));
+            Assert.assertEquals(2, dataSource.getPoolingCount());
+        }
+
+        dataSource.setMaxActive(1);
+        dataSource.shrink();
+        Assert.assertEquals(1, dataSource.getPoolingCount());
+
+        for (int i = 0; i < 10; ++i) {
+            Assert.assertEquals(1, connect(2));
+            Assert.assertEquals(1, dataSource.getPoolingCount());
+        }
+
+        Exception error = null;
+        try {
+            dataSource.setMaxActive(0);
+        } catch (IllegalArgumentException e) {
+            error = e;
+        }
+        Assert.assertNotNull(error);
+        Assert.assertEquals(1, dataSource.getMaxActive());
     }
 
     public int connect(int count) throws Exception {
@@ -91,7 +118,7 @@ public class MaxActiveChangeTest extends TestCase {
         for (int i = 0; i < count; ++i) {
             JdbcUtils.close(connections[i]);
         }
-        
+
         return successCount;
     }
 }