Execute listeners on current thread if threadpool is shutting down

src/main/java/org/elasticsearch/action/support/TransportAction.java

@@ -22,7 +22,9 @@ package org.elasticsearch.action.support;
 import org.elasticsearch.ElasticSearchException;
 import org.elasticsearch.action.*;
 import org.elasticsearch.common.component.AbstractComponent;
+import org.elasticsearch.common.logging.ESLogger;
 import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.util.concurrent.EsRejectedExecutionException;
 import org.elasticsearch.threadpool.ThreadPool;
 
 import static org.elasticsearch.action.support.PlainActionFuture.newFuture;
@@ -50,7 +52,7 @@ public abstract class TransportAction<Request extends ActionRequest, Response ex
 
     public void execute(Request request, ActionListener<Response> listener) {
         if (request.listenerThreaded()) {
-            listener = new ThreadedActionListener<Response>(threadPool, listener);
+            listener = new ThreadedActionListener<Response>(threadPool, listener, logger);
         }
         ActionRequestValidationException validationException = request.validate();
         if (validationException != null) {
@@ -67,19 +69,23 @@ public abstract class TransportAction<Request extends ActionRequest, Response ex
 
     protected abstract void doExecute(Request request, ActionListener<Response> listener);
 
-    static class ThreadedActionListener<Response> implements ActionListener<Response> {
+    static final class ThreadedActionListener<Response> implements ActionListener<Response> {
 
         private final ThreadPool threadPool;
 
         private final ActionListener<Response> listener;
 
-        ThreadedActionListener(ThreadPool threadPool, ActionListener<Response> listener) {
+        private final ESLogger logger;
+
+        ThreadedActionListener(ThreadPool threadPool, ActionListener<Response> listener, ESLogger logger) {
             this.threadPool = threadPool;
             this.listener = listener;
+            this.logger = logger;
         }
 
         @Override
         public void onResponse(final Response response) {
+            try {
                 threadPool.generic().execute(new Runnable() {
                     @Override
                     public void run() {
@@ -90,16 +96,33 @@ public abstract class TransportAction<Request extends ActionRequest, Response ex
                         }
                     }
                 });
+            } catch (EsRejectedExecutionException ex) {
+                logger.debug("Can not run threaded action, exectuion rejected [{}] running on current thread", listener);
+                /* we don't care if that takes long since we are shutting down. But if we not respond somebody could wait
+                 * for the response on the listener side which could be a remote machine so make sure we push it out there.*/
+                try {
+                    listener.onResponse(response);
+                } catch (Throwable e) {
+                    listener.onFailure(e);
+                }
+            }
         }
         
         @Override
         public void onFailure(final Throwable e) {
+            try {
                 threadPool.generic().execute(new Runnable() {
                     @Override
                     public void run() {
                         listener.onFailure(e);
                     }
                 });
+            } catch (EsRejectedExecutionException ex) {
+                logger.debug("Can not run threaded action, exectuion rejected for listener [{}] running on current thread", listener);
+                /* we don't care if that takes long since we are shutting down. But if we not respond somebody could wait
+                 * for the response on the listener side which could be a remote machine so make sure we push it out there.*/
+                listener.onFailure(e);
+            }
         }
     }
 }