diff --git a/src/main/java/com/alibaba/druid/pool/DruidDataSource.java b/src/main/java/com/alibaba/druid/pool/DruidDataSource.java
index b84aff1329..96ad305528 100644
--- a/src/main/java/com/alibaba/druid/pool/DruidDataSource.java
+++ b/src/main/java/com/alibaba/druid/pool/DruidDataSource.java
@@ -431,10 +431,20 @@ public class DruidDataSource extends DruidAbstractDataSource implements DruidDat
             if (count == 0) {
                 lowWater.signal();
 
-                notEmpty.awaitNanos(nanos);
+                long estimate = nanos;
+                for (;;) {
+                    estimate = notEmpty.awaitNanos(estimate);
 
-                if (count == 0) {
-                    return null;
+                    if (count == 0) {
+                        if (estimate > 0) {
+                            nanos = estimate;
+                            continue;
+                        }
+                        
+                        return null;
+                    }
+                    
+                    break;
                 }
             }
 
diff --git a/src/test/java/com/alibaba/druid/pool/benckmark/Case3.java b/src/test/java/com/alibaba/druid/pool/benckmark/Case3.java
new file mode 100644
index 0000000000..e34691f8e1
--- /dev/null
+++ b/src/test/java/com/alibaba/druid/pool/benckmark/Case3.java
@@ -0,0 +1,115 @@
+package com.alibaba.druid.pool.benckmark;
+
+import java.sql.Connection;
+import java.text.NumberFormat;
+import java.util.concurrent.CountDownLatch;
+
+import javax.sql.DataSource;
+
+import junit.framework.TestCase;
+
+import org.apache.commons.dbcp.BasicDataSource;
+
+import com.alibaba.druid.TestUtil;
+import com.alibaba.druid.pool.DruidDataSource;
+
+public class Case3 extends TestCase {
+
+    private String  jdbcUrl;
+    private String  user;
+    private String  password;
+    private String  driverClass;
+    private int     maxIdle         = 40;
+    private int     maxActive       = 140;
+    private int     maxWait         = 50;
+    private String  validationQuery = "SELECT 1";
+    private int     threadCount     = 14;
+    private int     loopCount       = 5;
+    final int       LOOP_COUNT      = 1000 * 100;
+    private boolean testOnBorrow    = true;
+
+    protected void setUp() throws Exception {
+        jdbcUrl = "jdbc:fake:dragoon_v25masterdb";
+        user = "dragoon25";
+        password = "dragoon25";
+        driverClass = "com.alibaba.druid.mock.MockDriver";
+    }
+
+    public void test_0() throws Exception {
+        DruidDataSource dataSource = new DruidDataSource();
+
+        dataSource.setMaxActive(maxActive);
+        dataSource.setMaxIdle(maxIdle);
+        dataSource.setMaxWait(maxWait);
+        dataSource.setPoolPreparedStatements(true);
+        dataSource.setDriverClassName(driverClass);
+        dataSource.setUrl(jdbcUrl);
+        dataSource.setPoolPreparedStatements(true);
+        dataSource.setUsername(user);
+        dataSource.setPassword(password);
+        dataSource.setValidationQuery(validationQuery);
+        dataSource.setTestOnBorrow(testOnBorrow);
+
+        for (int i = 0; i < loopCount; ++i) {
+            p0(dataSource, "druid", threadCount);
+        }
+        System.out.println();
+    }
+
+    public void test_1() throws Exception {
+        final BasicDataSource dataSource = new BasicDataSource();
+
+        dataSource.setMaxActive(maxActive);
+        dataSource.setMaxIdle(maxIdle);
+        dataSource.setMaxWait(maxWait);
+        dataSource.setPoolPreparedStatements(true);
+        dataSource.setDriverClassName(driverClass);
+        dataSource.setUrl(jdbcUrl);
+        dataSource.setPoolPreparedStatements(true);
+        dataSource.setUsername(user);
+        dataSource.setPassword(password);
+        dataSource.setValidationQuery("SELECT 1");
+        dataSource.setTestOnBorrow(testOnBorrow);
+
+        for (int i = 0; i < loopCount; ++i) {
+            p0(dataSource, "dbcp", threadCount);
+        }
+        System.out.println();
+    }
+
+    private void p0(final DataSource dataSource, String name, int threadCount) throws Exception {
+
+        final CountDownLatch startLatch = new CountDownLatch(1);
+        final CountDownLatch endLatch = new CountDownLatch(1);
+        for (int i = 0; i < threadCount; ++i) {
+            Thread thread = new Thread() {
+
+                public void run() {
+                    try {
+                        startLatch.await();
+
+                        for (int i = 0; i < LOOP_COUNT; ++i) {
+                            Connection conn = dataSource.getConnection();
+                            conn.close();
+                        }
+                    } catch (Exception ex) {
+                        ex.printStackTrace();
+                    }
+                    endLatch.countDown();
+                }
+            };
+            thread.start();
+        }
+        long startMillis = System.currentTimeMillis();
+        long startYGC = TestUtil.getYoungGC();
+        long startFullGC = TestUtil.getFullGC();
+        startLatch.countDown();
+        endLatch.await();
+
+        long millis = System.currentTimeMillis() - startMillis;
+        long ygc = TestUtil.getYoungGC() - startYGC;
+        long fullGC = TestUtil.getFullGC() - startFullGC;
+
+        System.out.println("thread " + threadCount + " " + name + " millis : " + NumberFormat.getInstance().format(millis) + ", YGC " + ygc + " FGC " + fullGC);
+    }
+}