use dedicated method to shutdown search executor

also shut it down in webapp

Author: vladak

opengrok-indexer/src/main/java/org/opengrok/indexer/configuration/RuntimeEnvironment.java

@@ -203,6 +203,15 @@ private ExecutorService newSearchExecutor() {
                 });
     }
 
+    public void shutdownSearchExecutor() {
+        getSearchExecutor().shutdownNow();
+        try {
+            getSearchExecutor().awaitTermination(getIndexerCommandTimeout(), TimeUnit.SECONDS);
+        } catch (InterruptedException e) {
+            LOGGER.log(Level.WARNING, "failed to await shutdown of search executor", e);
+        }
+    }
+
     public ExecutorService getRevisionExecutor() {
         return lzRevisionExecutor.get();
     }

opengrok-indexer/src/main/java/org/opengrok/indexer/index/Indexer.java

@@ -413,7 +413,7 @@ public static void main(String[] argv) {
             System.err.println("Exception: " + e.getLocalizedMessage());
             System.exit(1);
         } finally {
-            env.getSearchExecutor().shutdownNow();
+            env.shutdownSearchExecutor();
             stats.report(LOGGER, "Indexer finished", "indexer.total");
         }
     }

opengrok-web/src/main/java/org/opengrok/web/WebappListener.java

@@ -18,7 +18,7 @@
  */
 
 /*
- * Copyright (c) 2007, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2007, 2022, Oracle and/or its affiliates. All rights reserved.
  * Portions Copyright (c) 2018, 2019, Chris Fraire <cfraire@me.com>.
  */
 package org.opengrok.web;
@@ -167,6 +167,7 @@ public void contextDestroyed(final ServletContextEvent servletContextEvent) {
         env.stopExpirationTimer();
         try {
             env.shutdownRevisionExecutor();
+            env.shutdownSearchExecutor();
         } catch (InterruptedException e) {
             LOGGER.log(Level.WARNING, "Could not shutdown revision executor", e);
         }