From bec1a49a5413b1f716cb4c335d7477c2c54f9d01 Mon Sep 17 00:00:00 2001
From: Nik Everett <nik9000@gmail.com>
Date: Wed, 21 Jun 2017 12:21:48 -0400
Subject: [PATCH] Javadoc: ThreadPool doesn't reject while shutdown (#23678)

It caught me offguard yesterday that our executors won't always
reject when the ThreadPool is shutdown.
---
 .../elasticsearch/threadpool/ThreadPool.java    | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/core/src/main/java/org/elasticsearch/threadpool/ThreadPool.java b/core/src/main/java/org/elasticsearch/threadpool/ThreadPool.java
index b61da9c27f1..e7efe3ba3be 100644
--- a/core/src/main/java/org/elasticsearch/threadpool/ThreadPool.java
+++ b/core/src/main/java/org/elasticsearch/threadpool/ThreadPool.java
@@ -54,6 +54,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.concurrent.Executor;
 import java.util.concurrent.ExecutorService;
+import java.util.concurrent.RejectedExecutionException;
 import java.util.concurrent.RejectedExecutionHandler;
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.ScheduledFuture;
@@ -298,16 +299,24 @@ public class ThreadPool extends AbstractComponent implements Closeable {
     }
 
     /**
-     * Get the generic executor service. This executor service {@link Executor#execute(Runnable)} method will run the {@link Runnable} it
-     * is given in the {@link ThreadContext} of the thread that queues it.
+     * Get the generic {@link ExecutorService}. This executor service
+     * {@link Executor#execute(Runnable)} method will run the {@link Runnable} it is given in the
+     * {@link ThreadContext} of the thread that queues it.
+     * <p>
+     * Warning: this {@linkplain ExecutorService} will not throw {@link RejectedExecutionException}
+     * if you submit a task while it shutdown. It will instead silently queue it and not run it.
      */
     public ExecutorService generic() {
         return executor(Names.GENERIC);
     }
 
     /**
-     * Get the executor service with the given name. This executor service's {@link Executor#execute(Runnable)} method will run the
-     * {@link Runnable} it is given in the {@link ThreadContext} of the thread that queues it.
+     * Get the {@link ExecutorService} with the given name. This executor service's
+     * {@link Executor#execute(Runnable)} method will run the {@link Runnable} it is given in the
+     * {@link ThreadContext} of the thread that queues it.
+     * <p>
+     * Warning: this {@linkplain ExecutorService} might not throw {@link RejectedExecutionException}
+     * if you submit a task while it shutdown. It will instead silently queue it and not run it.
      *
      * @param name the name of the executor service to obtain
      * @throws IllegalArgumentException if no executor service with the specified name exists