Github user spmallette commented on a diff in the pull request:
https://github.com/apache/tinkerpop/pull/899#discussion_r206483311
--- Diff:
gremlin-server/src/main/java/org/apache/tinkerpop/gremlin/server/ResponseHandlerContext.java
---
@@ -0,0 +1,85 @@
+/*
+ * 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.tinkerpop.gremlin.server;
+
+import org.apache.tinkerpop.gremlin.driver.message.ResponseMessage;
+import org.apache.tinkerpop.gremlin.driver.message.ResponseStatusCode;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.concurrent.atomic.AtomicBoolean;
+
+/**
+ * A context for asynchronously writing response messages related to a
particular request.
+ * <p>The "write" methods of this class ensure that at most one {@link
ResponseStatusCode#isFinalResponse() final}
+ * response message is written to the underlying channel. Attempts to
write more than one final response message will
+ * be ignored with a warning log message.</p>
+ * <p>Note: an object of this class should be used instead of writing to
the channel directly when multiple threads
+ * are expected to produce final response messages concurrently. Callers
must ensure that the same
+ * {@link ResponseHandlerContext} is used by all threads writing response
messages for the same request.</p>
+ *
+ * @author Dmitri Bourlatchkov
+ */
+public class ResponseHandlerContext {
+ private static final Logger logger =
LoggerFactory.getLogger(ResponseHandlerContext.class);
+
+ private final Context context;
+ private final AtomicBoolean finalResponseWritten = new AtomicBoolean();
+
+ public ResponseHandlerContext(Context context) {
--- End diff --
Please make a pass through your PR to look for additional places where you
can `final` variables - it's our code style to be explicit in that way.
---
