From: Tuukka Lehtonen <tuukka.lehtonen@semantum.fi>
Date: Wed, 20 Jun 2018 08:07:58 +0000 (+0300)
Subject: Allow ExecutorWorker thread pool shutdown
X-Git-Tag: v1.43.0~136^2~457
X-Git-Url: https://gerrit.simantics.org/r/gitweb?p=simantics%2Fplatform.git;a=commitdiff_plain;h=951846b17c8c02759b7a319b0f2952cafacb8bea

Allow ExecutorWorker thread pool shutdown

Also made the pool spawn daemon threads to allow shutdown regardless of
whether the pool is shut down or not.

gitlab #29

Change-Id: I680e15407c0fd0586070a212d291efd44dc28f5d
---

diff --git a/bundles/org.simantics.utils.thread/src/org/simantics/utils/threads/ExecutorWorker.java b/bundles/org.simantics.utils.thread/src/org/simantics/utils/threads/ExecutorWorker.java
index e63b304e9..698d99e97 100644
--- a/bundles/org.simantics.utils.thread/src/org/simantics/utils/threads/ExecutorWorker.java
+++ b/bundles/org.simantics.utils.thread/src/org/simantics/utils/threads/ExecutorWorker.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2007, 2010 Association for Decentralized Information Management
+ * Copyright (c) 2007, 2018 Association for Decentralized Information Management
  * in Industry THTH ry.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
@@ -8,58 +8,71 @@
  *
  * Contributors:
  *     VTT Technical Research Centre of Finland - initial API and implementation
+ *     Semantum Oy - added shutdown facilities
  *******************************************************************************/
-/*
- *
- * @author Toni Kalajainen
- */
+
 package org.simantics.utils.threads;
 
 import java.util.concurrent.Callable;
 import java.util.concurrent.ScheduledFuture;
 import java.util.concurrent.ScheduledThreadPoolExecutor;
 import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
 
-
+/**
+ * @author Toni Kalajainen
+ * @author Tuukka Lehtonen
+ */
 public class ExecutorWorker {
-	
-	private static ExecutorWorker instance;
-	
-	static class DelayedExecution implements Comparable<DelayedExecution> {
-		Executable executable;
-		long executionTime;
-		@Override
-		public int compareTo(DelayedExecution o) {
-			if (o.executionTime<executionTime) return -1;
-			if (o.executionTime>executionTime) return 1;
-			return 0;
-		}
-	}
 
-	public static ExecutorWorker getInstance()
-	{
-		if (instance == null)
-			instance = new ExecutorWorker();
+	private static volatile ExecutorWorker instance;
+
+	public static ExecutorWorker getInstance() {
+		if (instance == null) {
+			synchronized (ExecutorWorker.class) {
+				if (instance == null)
+					instance = new ExecutorWorker();
+			}
+		}
 		return instance;
 	}
-	
-	ExecutorWorker() {		
-	}	
 
-	ScheduledThreadPoolExecutor pool = new ScheduledThreadPoolExecutor(1);
-	
+	private ExecutorWorker() {}
+
+	private final AtomicInteger counter = new AtomicInteger(0);
+	private final ThreadGroup threadGroup = new ThreadGroup("ExecutorWorker-Group");
+	private ScheduledThreadPoolExecutor pool = new ScheduledThreadPoolExecutor(1, r -> {
+		Thread t = new Thread(threadGroup, r, "ExecutorWorker-" + (counter.incrementAndGet()));
+		if (!t.isDaemon())
+			t.setDaemon(true);
+		if (t.getPriority() != Thread.NORM_PRIORITY)
+			t.setPriority(Thread.NORM_PRIORITY);
+		return t;
+	});
+
 	public synchronized ScheduledFuture<Object> timerExec(final Executable executable, int delay)
 	{
-		Callable<Object> c = new Callable<Object>() {
-			@Override
-			public Object call() throws Exception {
-                // FIXME: executable.runnable gets called twice!
-				ThreadUtils.asyncExec(executable.threadAccess, executable.runnable);
-				//executable.runnable.run();
-				return null;
-			}
-		};		
+		Callable<Object> c = () -> {
+			ThreadUtils.asyncExec(executable.threadAccess, executable.runnable);
+			return null;
+		};
 		return pool.schedule(c, delay, TimeUnit.MILLISECONDS);
 	}
 
+	private void shutdownThis() {
+		ScheduledThreadPoolExecutor e = pool;
+		if (e != null) {
+			pool = null;
+			ThreadUtils.shutdownAndAwaitTermination(e, 1000);
+		}
+	}
+
+	public static synchronized void shutdown() {
+		ExecutorWorker i = instance;
+		if (i != null) {
+			instance = null;
+			i.shutdownThis();
+		}
+	}
+
 }
diff --git a/bundles/org.simantics.utils.thread/src/org/simantics/utils/threads/ThreadUtils.java b/bundles/org.simantics.utils.thread/src/org/simantics/utils/threads/ThreadUtils.java
index cd8d6027e..15e818416 100644
--- a/bundles/org.simantics.utils.thread/src/org/simantics/utils/threads/ThreadUtils.java
+++ b/bundles/org.simantics.utils.thread/src/org/simantics/utils/threads/ThreadUtils.java
@@ -882,7 +882,7 @@ public class ThreadUtils {
      * 
      * @param pool {@link ExecutorService} to shut down
      */
-    private static void shutdownAndAwaitTermination(ExecutorService pool, long timeoutMs) {
+    static void shutdownAndAwaitTermination(ExecutorService pool, long timeoutMs) {
         //long t = System.currentTimeMillis();
         pool.shutdown(); // Disable new tasks from being submitted
         try {
diff --git a/bundles/org.simantics.workbench/src/org/simantics/workbench/internal/SimanticsWorkbenchAdvisor.java b/bundles/org.simantics.workbench/src/org/simantics/workbench/internal/SimanticsWorkbenchAdvisor.java
index 591c7fd42..29ee52e61 100644
--- a/bundles/org.simantics.workbench/src/org/simantics/workbench/internal/SimanticsWorkbenchAdvisor.java
+++ b/bundles/org.simantics.workbench/src/org/simantics/workbench/internal/SimanticsWorkbenchAdvisor.java
@@ -106,6 +106,7 @@ import org.simantics.ui.jobs.SessionGarbageCollectorJob;
 import org.simantics.ui.workbench.PerspectiveBarsActivator;
 import org.simantics.ui.workbench.PerspectiveContextActivator;
 import org.simantics.utils.logging.TimeLogger;
+import org.simantics.utils.threads.ExecutorWorker;
 import org.simantics.utils.threads.ThreadUtils;
 import org.simantics.utils.ui.dialogs.ShowError;
 import org.simantics.utils.ui.dialogs.ShowMessage;
@@ -749,6 +750,7 @@ public class SimanticsWorkbenchAdvisor extends WorkbenchAdvisor {
 
                 progress.subTask("Thread pools");
                 ThreadUtils.shutdown();
+                ExecutorWorker.shutdown();
                 progress.worked(5);
 
                 progress.subTask("Clear index status");