[fix][plugin][pulsar] Clean message context after message is recycled to prevent memory leak. (#405)

Author: tjiuming

apm-sniffer/apm-sdk-plugin/pulsar-common/src/main/java/org/apache/skywalking/apm/plugin/pulsar/common/MessageRecycleMethodInterceptor.java

@@ -0,0 +1,41 @@
+/*
+ * 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.skywalking.apm.plugin.pulsar.common;
+
+import java.lang.reflect.Method;
+import org.apache.skywalking.apm.agent.core.plugin.interceptor.enhance.EnhancedInstance;
+import org.apache.skywalking.apm.agent.core.plugin.interceptor.enhance.InstanceMethodsAroundInterceptor;
+import org.apache.skywalking.apm.agent.core.plugin.interceptor.enhance.MethodInterceptResult;
+
+public class MessageRecycleMethodInterceptor implements InstanceMethodsAroundInterceptor {
+    @Override
+    public void beforeMethod(EnhancedInstance objInst, Method method, Object[] allArguments, Class<?>[] argumentsTypes, MethodInterceptResult result) throws Throwable {
+        objInst.setSkyWalkingDynamicField(null);
+    }
+
+    @Override
+    public Object afterMethod(EnhancedInstance objInst, Method method, Object[] allArguments, Class<?>[] argumentsTypes, Object ret) throws Throwable {
+        return ret;
+    }
+
+    @Override
+    public void handleMethodException(EnhancedInstance objInst, Method method, Object[] allArguments, Class<?>[] argumentsTypes, Throwable t) {
+        // NOOP
+    }
+}

apm-sniffer/apm-sdk-plugin/pulsar-common/src/main/java/org/apache/skywalking/apm/plugin/pulsar/common/define/BaseMessageInstrumentation.java

@@ -18,6 +18,10 @@
 
 package org.apache.skywalking.apm.plugin.pulsar.common.define;
 
+import static net.bytebuddy.matcher.ElementMatchers.isMethod;
+import static net.bytebuddy.matcher.ElementMatchers.isPublic;
+import static net.bytebuddy.matcher.ElementMatchers.named;
+import static net.bytebuddy.matcher.ElementMatchers.takesArguments;
 import static org.apache.skywalking.apm.agent.core.plugin.match.NameMatch.byName;
 
 import net.bytebuddy.description.method.MethodDescription;
@@ -42,10 +46,12 @@ public class BaseMessageInstrumentation extends ClassInstanceMethodsEnhancePlugi
 
     public static final String ENHANCE_CLASS = "org.apache.pulsar.client.impl.MessageImpl";
     public static final String CONSTRUCTOR_INTERCEPTOR_CLASS = "org.apache.skywalking.apm.plugin.pulsar.common.MessageConstructorInterceptor";
+    public static final String ENHANCE_METHOD = "recycle";
+    public static final String METHOD_INTERCEPTOR_CLASS = "org.apache.skywalking.apm.plugin.pulsar.common.MessageRecycleMethodInterceptor";
 
     @Override
     public ConstructorInterceptPoint[] getConstructorsInterceptPoints() {
-        return new ConstructorInterceptPoint[] {
+        return new ConstructorInterceptPoint[]{
                 new ConstructorInterceptPoint() {
                     @Override
                     public ElementMatcher<MethodDescription> getConstructorMatcher() {
@@ -62,7 +68,24 @@ public String getConstructorInterceptor() {
 
     @Override
     public InstanceMethodsInterceptPoint[] getInstanceMethodsInterceptPoints() {
-        return new InstanceMethodsInterceptPoint[0];
+        return new InstanceMethodsInterceptPoint[]{
+                new InstanceMethodsInterceptPoint() {
+                    @Override
+                    public ElementMatcher<MethodDescription> getMethodsMatcher() {
+                        return isMethod().and(named(ENHANCE_METHOD)).and(isPublic()).and(takesArguments(0));
+                    }
+
+                    @Override
+                    public String getMethodsInterceptor() {
+                        return METHOD_INTERCEPTOR_CLASS;
+                    }
+
+                    @Override
+                    public boolean isOverrideArgs() {
+                        return false;
+                    }
+                }
+        };
     }
 
     @Override