[Dubbo-1665] Elegant shutdown under tomcat #1665

all/pom.xml

@@ -319,6 +319,13 @@
             <scope>compile</scope>
             <optional>true</optional>
         </dependency>
+        <dependency>
+            <groupId>com.alibaba</groupId>
+            <artifactId>dubbo-bootstrap</artifactId>
+            <version>${project.version}</version>
+            <scope>compile</scope>
+            <optional>true</optional>
+        </dependency>
         <dependency>
             <groupId>com.alibaba</groupId>
             <artifactId>hessian-lite</artifactId>
@@ -418,6 +425,7 @@
                                     <include>com.alibaba:dubbo-serialization-fst</include>
                                     <include>com.alibaba:dubbo-serialization-kryo</include>
                                     <include>com.alibaba:dubbo-serialization-jdk</include>
+                                    <include>com.alibaba:dubbo-bootstrap</include>
                                 </includes>
                             </artifactSet>
                             <transformers>

dubbo-bootstrap/pom.xml

@@ -0,0 +1,47 @@
+<!--
+  Licensed to the Apache Software Foundation (ASF) under one or more
+  contributor license agreements.  See the NOTICE file distributed with
+  this work for additional information regarding copyright ownership.
+  The ASF licenses this file to You under the Apache License, Version 2.0
+  (the "License"); you may not use this file except in compliance with
+  the License.  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+  -->
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <artifactId>dubbo-parent</artifactId>
+        <groupId>com.alibaba</groupId>
+        <version>2.6.2-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>dubbo-bootstrap</artifactId>
+
+
+    <dependencies>
+        <dependency>
+            <groupId>com.alibaba</groupId>
+            <artifactId>dubbo-config-api</artifactId>
+            <version>${project.parent.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.alibaba</groupId>
+            <artifactId>dubbo-common</artifactId>
+            <version>${project.parent.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.alibaba</groupId>
+            <artifactId>dubbo-registry-api</artifactId>
+            <version>${project.parent.version}</version>
+        </dependency>
+    </dependencies>
+</project>

dubbo-bootstrap/src/main/java/org/apache/dubbo/bootstrap/DubboBootstrap.java

@@ -0,0 +1,133 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.dubbo.bootstrap;
+
+import com.alibaba.dubbo.common.extension.ExtensionLoader;
+import com.alibaba.dubbo.common.logger.Logger;
+import com.alibaba.dubbo.common.logger.LoggerFactory;
+import com.alibaba.dubbo.config.ServiceConfig;
+import com.alibaba.dubbo.registry.support.AbstractRegistryFactory;
+import com.alibaba.dubbo.rpc.Protocol;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+/**
+ * A bootstrap class to easily start and stop Dubbo via programmatic API.
+ * The bootstrap class will be responsible to cleanup the resources during stop.
+ */
+public class DubboBootstrap {
+
+    private static final Logger logger = LoggerFactory.getLogger(DubboBootstrap.class);
+
+    /**
+     * The list of ServiceConfig
+     */
+    private List<ServiceConfig> serviceConfigList;
+
+    /**
+     * Has it already been destroyed or not?
+     */
+    private final AtomicBoolean destroyed;
+
+    /**
+     * The shutdown hook used when Dubbo is running under embedded environment
+     */
+    private Thread shutdownHook;
+
+    public DubboBootstrap() {
+        this.serviceConfigList = new ArrayList<ServiceConfig>();
+        this.destroyed = new AtomicBoolean(false);
+        this.shutdownHook = new Thread(new Runnable() {
+            @Override
+            public void run() {
+                if (logger.isInfoEnabled()) {
+                    logger.info("Run shutdown hook now.");
+                }
+                destroy();
+            }
+        }, "DubboShutdownHook");
+    }
+
+    /**
+     * Register service config to bootstrap, which will be called during {@link DubboBootstrap#stop()}
+     * @param serviceConfig the service
+     * @return the bootstrap instance
+     */
+    public DubboBootstrap regsiterServiceConfig(ServiceConfig serviceConfig) {
+        serviceConfigList.add(serviceConfig);
+        return this;
+    }
+
+    public void start() {
+        registerShutdownHook();
+        for (ServiceConfig serviceConfig: serviceConfigList) {
+            serviceConfig.export();
+        }
+    }
+
+    public void stop() {
+        for (ServiceConfig serviceConfig: serviceConfigList) {
+            serviceConfig.unexport();
+        }
+        destroy();
+        removeShutdownHook();
+    }
+
+    /**
+     * Register the shutdown hook
+     */
+    public void registerShutdownHook() {
+        Runtime.getRuntime().addShutdownHook(shutdownHook);
+    }
+
+    /**
+     * Remove this shutdown hook
+     */
+    public void removeShutdownHook() {
+        try {
+            Runtime.getRuntime().removeShutdownHook(shutdownHook);
+        }
+        catch (IllegalStateException ex) {
+            // ignore - VM is already shutting down
+        }
+    }
+
+    /**
+     * Destroy all the resources, including registries and protocols.
+     */
+    private void destroy() {
+        if (!destroyed.compareAndSet(false, true)) {
+            return;
+        }
+        // destroy all the registries
+        AbstractRegistryFactory.destroyAll();
+        // destroy all the protocols
+        ExtensionLoader<Protocol> loader = ExtensionLoader.getExtensionLoader(Protocol.class);
+        for (String protocolName : loader.getLoadedExtensions()) {
+            try {
+                Protocol protocol = loader.getLoadedExtension(protocolName);
+                if (protocol != null) {
+                    protocol.destroy();
+                }
+            } catch (Throwable t) {
+                logger.warn(t.getMessage(), t);
+            }
+        }
+    }
+}

dubbo-common/src/main/java/com/alibaba/dubbo/common/utils/ExecutorUtil.java

@@ -43,19 +43,27 @@ public static boolean isTerminated(Executor executor) {
         return false;
     }
 
+    /**
+     * Use the shutdown pattern from:
+     *  https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/ExecutorService.html
+     * @param executor the Executor to shutdown
+     * @param timeout the timeout in milliseconds before termination
+     */
     public static void gracefulShutdown(Executor executor, int timeout) {
         if (!(executor instanceof ExecutorService) || isTerminated(executor)) {
             return;
         }
         final ExecutorService es = (ExecutorService) executor;
         try {
-            es.shutdown(); // Disable new tasks from being submitted
+            // Disable new tasks from being submitted
+            es.shutdown();
         } catch (SecurityException ex2) {
             return;
         } catch (NullPointerException ex2) {
             return;
         }
         try {
+            // Wait a while for existing tasks to terminate
             if (!es.awaitTermination(timeout, TimeUnit.MILLISECONDS)) {
                 es.shutdownNow();
             }

dubbo-config/dubbo-config-api/src/main/java/com/alibaba/dubbo/config/AbstractConfig.java

@@ -73,18 +73,6 @@ public abstract class AbstractConfig implements Serializable {
         legacyProperties.put("dubbo.service.url", "dubbo.service.address");
     }
 
-    static {
-        Runtime.getRuntime().addShutdownHook(new Thread(new Runnable() {
-            @Override
-            public void run() {
-                if (logger.isInfoEnabled()) {
-                    logger.info("Run shutdown hook now.");
-                }
-                ProtocolConfig.destroyAll();
-            }
-        }, "DubboShutdownHook"));
-    }
-
     protected String id;
 
     private static String convertLegacyValue(String key, String value) {

dubbo-config/dubbo-config-api/src/main/java/com/alibaba/dubbo/config/ProtocolConfig.java

@@ -21,7 +21,6 @@
 import com.alibaba.dubbo.common.status.StatusChecker;
 import com.alibaba.dubbo.common.threadpool.ThreadPool;
 import com.alibaba.dubbo.config.support.Parameter;
-import com.alibaba.dubbo.registry.support.AbstractRegistryFactory;
 import com.alibaba.dubbo.remoting.Codec;
 import com.alibaba.dubbo.remoting.Dispatcher;
 import com.alibaba.dubbo.remoting.Transporter;
@@ -30,7 +29,6 @@
 import com.alibaba.dubbo.rpc.Protocol;
 
 import java.util.Map;
-import java.util.concurrent.atomic.AtomicBoolean;
 
 /**
  * ProtocolConfig
@@ -135,8 +133,6 @@ public class ProtocolConfig extends AbstractConfig {
     // if it's default
     private Boolean isDefault;
 
-    private static final AtomicBoolean destroyed = new AtomicBoolean(false);
-
     public ProtocolConfig() {
     }
 
@@ -149,27 +145,6 @@ public ProtocolConfig(String name, int port) {
         setPort(port);
     }
 
-    // TODO: 2017/8/30 to move this method somewhere else
-    public static void destroyAll() {
-        if (!destroyed.compareAndSet(false, true)) {
-            return;
-        }
-
-        AbstractRegistryFactory.destroyAll();
-
-        ExtensionLoader<Protocol> loader = ExtensionLoader.getExtensionLoader(Protocol.class);
-        for (String protocolName : loader.getLoadedExtensions()) {
-            try {
-                Protocol protocol = loader.getLoadedExtension(protocolName);
-                if (protocol != null) {
-                    protocol.destroy();
-                }
-            } catch (Throwable t) {
-                logger.warn(t.getMessage(), t);
-            }
-        }
-    }
-
     @Parameter(excluded = true)
     public String getName() {
         return name;

dubbo-config/dubbo-config-api/src/main/java/com/alibaba/dubbo/config/RegistryConfig.java

@@ -18,7 +18,6 @@
 
 import com.alibaba.dubbo.common.Constants;
 import com.alibaba.dubbo.config.support.Parameter;
-import com.alibaba.dubbo.registry.support.AbstractRegistryFactory;
 
 import java.util.Map;
 
@@ -96,13 +95,9 @@ public RegistryConfig(String address) {
         setAddress(address);
     }
 
-    public static void destroyAll() {
-        AbstractRegistryFactory.destroyAll();
-    }
-
-    @Deprecated
-    public static void closeAll() {
-        destroyAll();
+    public RegistryConfig(String address, String protocol) {
+        setAddress(address);
+        setProtocol(protocol);
     }
 
     public String getProtocol() {

dubbo-config/dubbo-config-api/src/test/java/com/alibaba/dubbo/config/ProtocolConfigTest.java

@@ -17,7 +17,6 @@
 
 package com.alibaba.dubbo.config;
 
-import com.alibaba.dubbo.common.extension.ExtensionLoader;
 import com.alibaba.dubbo.rpc.Protocol;
 import org.junit.Test;
 import org.mockito.Mockito;
@@ -32,15 +31,6 @@
 import static org.junit.Assert.assertThat;
 
 public class ProtocolConfigTest {
-    @Test
-    public void testDestroyAll() throws Exception {
-        Protocol protocol = Mockito.mock(Protocol.class);
-        MockProtocol2.delegate = protocol;
-        ExtensionLoader<Protocol> loader = ExtensionLoader.getExtensionLoader(Protocol.class);
-        loader.getExtension("mockprotocol2");
-        ProtocolConfig.destroyAll();
-        Mockito.verify(protocol).destroy();
-    }
 
     @Test
     public void testDestroy() throws Exception {

dubbo-config/dubbo-config-spring/pom.xml

@@ -35,14 +35,28 @@
             <artifactId>dubbo-config-api</artifactId>
             <version>${project.parent.version}</version>
         </dependency>
+        <dependency>
+            <groupId>com.alibaba</groupId>
+            <artifactId>dubbo-bootstrap</artifactId>
+            <version>${project.parent.version}</version>
+        </dependency>
         <dependency>
             <groupId>org.springframework</groupId>
             <artifactId>spring-beans</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-web</artifactId>
+        </dependency>
         <dependency>
             <groupId>org.springframework</groupId>
             <artifactId>spring-context</artifactId>
         </dependency>
+        <dependency>
+            <groupId>javax.servlet</groupId>
+            <artifactId>javax.servlet-api</artifactId>
+            <scope>provided</scope>
+        </dependency>
         <dependency>
             <groupId>com.alibaba</groupId>
             <artifactId>dubbo-registry-default</artifactId>