X-Git-Url: https://git.opendaylight.org/gerrit/gitweb?a=blobdiff_plain;f=common%2Futil%2Fsrc%2Fmain%2Fjava%2Forg%2Fopendaylight%2Fyangtools%2Futil%2FExecutorServiceUtil.java;h=c6a933ab0d2fde82185a0436418430b1413c9664;hb=4f66528ebcf1603108218b8ebf48147d8ed3ad38;hp=36f729fb8ff69210e475ad67f8466f3dd973f5f0;hpb=cba18b8c8be59973f7d1b44a116f4ff1a0623183;p=yangtools.git

diff --git a/common/util/src/main/java/org/opendaylight/yangtools/util/ExecutorServiceUtil.java b/common/util/src/main/java/org/opendaylight/yangtools/util/ExecutorServiceUtil.java
index 36f729fb8f..c6a933ab0d 100644
--- a/common/util/src/main/java/org/opendaylight/yangtools/util/ExecutorServiceUtil.java
+++ b/common/util/src/main/java/org/opendaylight/yangtools/util/ExecutorServiceUtil.java
@@ -7,42 +7,47 @@
  */
 package org.opendaylight.yangtools.util;
 
+import com.google.common.util.concurrent.ForwardingBlockingQueue;
 import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.RejectedExecutionException;
 import java.util.concurrent.RejectedExecutionHandler;
 import java.util.concurrent.ThreadPoolExecutor;
-
+import java.util.concurrent.TimeUnit;
+import org.eclipse.jdt.annotation.NonNull;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import com.google.common.util.concurrent.ForwardingBlockingQueue;
-
 /**
  * Utility methods for dealing with {@link ExecutorService}s.
  */
 public final class ExecutorServiceUtil {
     private static final class WaitInQueueExecutionHandler implements RejectedExecutionHandler {
         @Override
+        @SuppressWarnings("checkstyle:parameterName")
         public void rejectedExecution(final Runnable r, final ThreadPoolExecutor executor) {
+            if (executor.isShutdown()) {
+                throw new RejectedExecutionException("Executor has been shutdown.");
+            }
+
             try {
                 executor.getQueue().put(r);
             } catch (InterruptedException e) {
-                LOG.debug("Intterupted while waiting for queue", e);
-                throw new RejectedExecutionException("Interrupted while waiting for queue", e);
+                LOG.debug("Interrupted while attempting to put to the queue", e);
+                throw new RejectedExecutionException("Interrupted while attempting to put to the queue", e);
             }
         }
     }
 
     private static final Logger LOG = LoggerFactory.getLogger(ExecutorServiceUtil.class);
-    private static final RejectedExecutionHandler WAIT_IN_QUEUE_HANDLER = new WaitInQueueExecutionHandler();
+    private static final @NonNull RejectedExecutionHandler WAIT_IN_QUEUE_HANDLER = new WaitInQueueExecutionHandler();
 
     private ExecutorServiceUtil() {
-        throw new UnsupportedOperationException("Utility class");
+        // Hidden on purpose
     }
 
     /**
-     * Create a {@link BlockingQueue} which does not allow for non-blocking addition to the queue.
+     * Creates a {@link BlockingQueue} which does not allow for non-blocking addition to the queue.
      * This is useful with {@link #waitInQueueExecutionHandler()} to turn force a
      * {@link ThreadPoolExecutor} to create as many threads as it is configured to before starting
      * to fill the queue.
@@ -50,9 +55,10 @@ public final class ExecutorServiceUtil {
      * @param delegate Backing blocking queue.
      * @return A new blocking queue backed by the delegate
      */
-    public <E> BlockingQueue<E> offerFailingBlockingQueue(final BlockingQueue<E> delegate) {
-        return new ForwardingBlockingQueue<E>() {
+    public static <E> @NonNull BlockingQueue<E> offerFailingBlockingQueue(final BlockingQueue<E> delegate) {
+        return new ForwardingBlockingQueue<>() {
             @Override
+            @SuppressWarnings("checkstyle:parameterName")
             public boolean offer(final E o) {
                 return false;
             }
@@ -65,12 +71,30 @@ public final class ExecutorServiceUtil {
     }
 
     /**
-     * Return a {@link RejectedExecutionHandler} which blocks on the {@link ThreadPoolExecutor}'s
+     * Returns a {@link RejectedExecutionHandler} which blocks on the {@link ThreadPoolExecutor}'s
      * backing queue if a new thread cannot be spawned.
      *
      * @return A shared RejectedExecutionHandler instance.
      */
-    public RejectedExecutionHandler waitInQueueExecutionHandler() {
+    public static @NonNull RejectedExecutionHandler waitInQueueExecutionHandler() {
         return WAIT_IN_QUEUE_HANDLER;
     }
+
+    /**
+     * Tries to shutdown the given executor gracefully by awaiting termination for the given
+     * timeout period. If the timeout elapses before termination, the executor is forcefully
+     * shutdown.
+     */
+    public static void tryGracefulShutdown(final @NonNull ExecutorService executor, final long timeout,
+            final @NonNull TimeUnit unit) {
+        executor.shutdown();
+
+        try {
+            if (!executor.awaitTermination(timeout, unit)) {
+                executor.shutdownNow();
+            }
+        } catch (InterruptedException e) {
+            executor.shutdownNow();
+        }
+    }
 }