git add DruidDataSource async init support.

src/main/java/com/alibaba/druid/pool/DruidDataSource.java

@@ -186,6 +186,14 @@ public class DruidDataSource extends DruidAbstractDataSource implements DruidDat
         configFromPropety(System.getProperties());
     }
 
+    public boolean isAsyncInit() {
+        return asyncInit;
+    }
+
+    public void setAsyncInit(boolean asyncInit) {
+        this.asyncInit = asyncInit;
+    }
+
     public void configFromPropety(Properties properties) {
         {
             String property = properties.getProperty("druid.name");
@@ -818,6 +826,7 @@ public class DruidDataSource extends DruidAbstractDataSource implements DruidDat
 
             SQLException connectError = null;
 
+            boolean asyncInit = this.asyncInit && createScheduler == null;
             if (!asyncInit) {
                 try {
                     // init connections
@@ -2211,7 +2220,14 @@ public class DruidDataSource extends DruidAbstractDataSource implements DruidDat
                 try {
                     boolean emptyWait = true;
 
-                    if (createError != null && poolingCount == 0 && !discardChanged) {
+                    if (createError != null
+                            && poolingCount == 0
+                            && !discardChanged) {
+                        emptyWait = false;
+                    }
+
+                    if (emptyWait
+                            && asyncInit && createCount.get() < initialSize) {
                         emptyWait = false;
                     }
 

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

@@ -0,0 +1,33 @@
+package com.alibaba.druid.bvt.pool;
+
+import com.alibaba.druid.pool.DruidDataSource;
+import junit.framework.TestCase;
+
+public class AsyncInitTest extends TestCase {
+    private DruidDataSource dataSource;
+
+    protected void setUp() throws Exception {
+        dataSource = new DruidDataSource();
+        dataSource.setAsyncInit(true);
+        dataSource.setUrl("jdbc:mock:xxx");
+        dataSource.setInitialSize(10);
+        dataSource.setMaxActive(10);
+    }
+
+    protected void tearDown() throws Exception {
+        dataSource.close();
+    }
+
+    public void test_async_init() throws Exception {
+        dataSource.init();
+
+        for (int i = 0; i < 1000; ++i) {
+            if (dataSource.getPoolingCount() == dataSource.getInitialSize()) {
+                break;
+            }
+            Thread.sleep(10);
+        }
+        assertEquals(10, dataSource.getPoolingCount());
+        assertEquals(10, dataSource.getCreateCount());
+    }
+}