[246406] Thread-safe support for Lazy Loading

releng/org.eclipse.rse.updatesite/site.xml

@@ -405,7 +405,7 @@
    </category-def>
 <!-- END_3_0_1 -->
 <!-- BEGIN_3_1 -->
-   <feature url="features/org.eclipse.rse.core_3.0.100.qualifier.jar" id="org.eclipse.rse.core" version="3.0.100.qualifier">
+   <feature url="features/org.eclipse.rse.core_3.1.0.qualifier.jar" id="org.eclipse.rse.core" version="3.1.0.qualifier">
       <category name="TM and RSE 3.1"/>
    </feature>
    <feature url="features/org.eclipse.rse.dstore_3.0.100.qualifier.jar" id="org.eclipse.rse.dstore" version="3.0.100.qualifier">
@@ -417,10 +417,10 @@
    <feature url="features/org.eclipse.rse.local_2.1.1.qualifier.jar" id="org.eclipse.rse.local" version="2.1.1.qualifier">
       <category name="TM and RSE 3.1"/>
    </feature>
-   <feature url="features/org.eclipse.rse_3.0.100.qualifier.jar" id="org.eclipse.rse" version="3.0.100.qualifier">
+   <feature url="features/org.eclipse.rse_3.1.0.qualifier.jar" id="org.eclipse.rse" version="3.1.0.qualifier">
       <category name="TM and RSE 3.1"/>
    </feature>
-   <feature url="features/org.eclipse.rse.sdk_3.0.100.qualifier.jar" id="org.eclipse.rse.sdk" version="3.0.100.qualifier">
+   <feature url="features/org.eclipse.rse.sdk_3.1.0.qualifier.jar" id="org.eclipse.rse.sdk" version="3.1.0.qualifier">
       <category name="TM and RSE 3.1"/>
    </feature>
    <feature url="features/org.eclipse.rse.ssh_2.1.100.qualifier.jar" id="org.eclipse.rse.ssh" version="2.1.100.qualifier">

rse/features/org.eclipse.rse-feature/feature.xml

@@ -2,7 +2,7 @@
 <feature
       id="org.eclipse.rse"
       label="%featureName"
-      version="3.0.100.qualifier"
+      version="3.1.0.qualifier"
       provider-name="%providerName"
       plugin="org.eclipse.rse"
       image="eclipse_update_120.jpg">

rse/features/org.eclipse.rse.core-feature/feature.xml

@@ -2,7 +2,7 @@
 <feature
       id="org.eclipse.rse.core"
       label="%featureName"
-      version="3.0.100.qualifier"
+      version="3.1.0.qualifier"
       provider-name="%providerName"
       plugin="org.eclipse.rse.core">
 

rse/features/org.eclipse.rse.sdk-feature/feature.xml

@@ -2,7 +2,7 @@
 <feature
       id="org.eclipse.rse.sdk"
       label="%featureName"
-      version="3.0.100.qualifier"
+      version="3.1.0.qualifier"
       provider-name="%providerName"
       image="eclipse_update_120.jpg">
 

rse/plugins/org.eclipse.rse.services/META-INF/MANIFEST.MF

@@ -2,7 +2,7 @@ Manifest-Version: 1.0
 Bundle-ManifestVersion: 2
 Bundle-Name: %pluginName
 Bundle-SymbolicName: org.eclipse.rse.services;singleton:=true
-Bundle-Version: 3.0.100.qualifier
+Bundle-Version: 3.1.0.qualifier
 Bundle-Activator: org.eclipse.rse.internal.services.Activator
 Bundle-Vendor: %providerName
 Bundle-Localization: plugin

rse/plugins/org.eclipse.rse.services/clientserver/org/eclipse/rse/services/clientserver/messages/SystemMessageFile.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2002, 2007 IBM Corporation and others.
+ * Copyright (c) 2002, 2008 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -7,12 +7,13 @@
  *
  * Initial Contributors:
  * The following IBM employees contributed to the Remote System Explorer
- * component that contains this file: David McKnight, Kushal Munir, 
+ * component that contains this file: David McKnight, Kushal Munir,
- * Michael Berger, David Dykstal, Phil Coulthard, Don Yantzi, Eric Simpson, 
+ * Michael Berger, David Dykstal, Phil Coulthard, Don Yantzi, Eric Simpson,
  * Emily Bruner, Mazen Faraj, Adrian Storisteanu, Li Ding, and Kent Hawley.
- * 
+ *
  * Contributors:
- * {Name} (company) - description of contribution.
+ * David McKnight   (IBM)  [246406] [performance] Timeout waiting when loading SystemPreferencesManager$ModelChangeListener during startup
+ * Martin Oberhuber (Wind River) - [246406] Thread-safe support for Lazy Loading
  *******************************************************************************/
 
 package org.eclipse.rse.services.clientserver.messages;
@@ -24,8 +25,11 @@ import java.io.InputStream;
 import java.io.PrintWriter;
 import java.net.URI;
 import java.net.URISyntaxException;
+import java.net.URL;
+import java.util.Collections;
 import java.util.Hashtable;
 import java.util.LinkedList;
+import java.util.List;
 import java.util.Vector;
 
 import javax.xml.parsers.DocumentBuilder;
@@ -44,17 +48,20 @@ import org.xml.sax.SAXParseException;
 
 
 /**
- * Use this class to open, and parse, a RSE-style message file.  
+ * Use this class to open, and parse, a RSE-style message file.
  */
 public class SystemMessageFile implements ErrorHandler
 {
 
-	
+	/**
-	private static final LinkedList msgfList=new LinkedList();
+	 * List<MessageFileInfo> of loaded message files to avoid double loading.
+	 * Must be synchronized since queried from multiple Threads.
+	 */
+	private static final List msgfList = Collections.synchronizedList(new LinkedList());
 	private MessageFileInfo msgFile;
 	private String defaultMsgFileLocation;
 	private InputStream dtdInputStream;
-	// the following is an attempt to improve response time, and reduce memory requirements, by 
+	// the following is an attempt to improve response time, and reduce memory requirements, by
 	//  caching SystemMessage objects for previously issued messages. Phil
 	private Hashtable messages = new Hashtable();
 	// XML TAG AND ELEMENT NAMES...
@@ -68,19 +75,24 @@ public class SystemMessageFile implements ErrorHandler
 	private static final String XML_ATTR_ID          = "ID"; //$NON-NLS-1$
 	private static final String XML_ATTR_INDICATOR   = "Indicator"; //$NON-NLS-1$
 	private static final String XML_ATTR_NAME        = "Name"; //$NON-NLS-1$
-						
+
-						
+	// when using lazy loading, this is the thread that loads the message file
-						
+	private final Thread fLoadThread;
+
+	// indicates whether the lazy load thread is done
+	private boolean fLoadThreadFinished = false;
+
 	/**
-	 * Inner class
+	 * File info node in msgfList to avoid duplicate loading.
+	 * Thread-safe since immutable.
 	 */
-	private class MessageFileInfo 
+	private static class MessageFileInfo
 	{
-		private String filename=null;
+		private final String filename;
-		private String shortName=null;
+		private final String shortName;
-		private Document xmlDocument=null;
+		private final Document xmlDocument;
-		
+
-		public MessageFileInfo(String ucFileName, String lcFileName, Document doc) 
+		public MessageFileInfo(String ucFileName, String lcFileName, Document doc)
 		{
 			filename=ucFileName;
 			int idx=lcFileName.lastIndexOf('\\');
@@ -88,61 +100,159 @@ public class SystemMessageFile implements ErrorHandler
 			  idx = lcFileName.lastIndexOf('/');
 			if (idx >= 0)
 			  shortName = lcFileName.substring(idx+1);
-			else 
+			else
 			  shortName = lcFileName;
 			xmlDocument=doc;
 		}
-		
+
-		public String getMessageFullFileName() 
+		public String getMessageFullFileName()
 		{
 			return filename;
 		}
-		public String getMessageShortFileName() 
+		public String getMessageShortFileName()
 		{
 			return shortName;
 		}
-		
+
-		public Document getXMLDocument() 
+		public Document getXMLDocument()
 		{
 			return xmlDocument;
 		}
 	}
 
 	/**
-	 * Constructor
+	 * Thread for loading a message file asynchronously.
-	 * @param messageFileName - a key used to determine if a message file has already been loaded. 
+	 *
-	 * Usually the name of the xml file containing the message file. 
+	 * Opens Streams, creates an internal message file info object holding the
-	 * @param messageFile the stream containing the message file.
+	 * DTD, and closes Streams. In case of error, the message file info object
-	 * @param dtdStream the stream containing the dtd for this message file.
+	 * is not set (remains <code>null</code>).
+	 *
+	 * As a result,
+	 * <ul>
+	 * <li>The {@link #msgFile} variable is set to the loaded message file info
+	 * node if successful.</li>
+	 * <li>The {@link #fLoadThreadFinished} is guaranteed to be set
+	 * <code>true</code>.</li>
+	 * <li>All waiting Threads are notified.</li>
+	 * </ul>
 	 */
-	public SystemMessageFile (String messageFileName, InputStream messageFile, InputStream dtdStream) 
+	private class LoadThread extends Thread {
+		private URL _messageFileURL;
+		private URL _dtdURL;
+		private String _messageFileName;
+
+		public LoadThread(String messageFileName, URL messageFileURL, URL dtdURL) {
+			_messageFileName = messageFileName;
+			_messageFileURL = messageFileURL;
+			_dtdURL = dtdURL;
+		}
+
+		public void run() {
+			InputStream messageFile = null;
+			InputStream dtdFile = null;
+			try {
+				messageFile = _messageFileURL.openStream();
+				dtdFile = _dtdURL.openStream();
+				SystemMessageFile realFile = new SystemMessageFile(_messageFileName, messageFile, dtdFile);
+				msgFile = realFile.msgFile;
+			} catch (IOException e) {
+				// problem loading message file -- msgFile is not set.
+			} finally {
+				// Notify that work is finished before closing Streams -
+				// Avoid not getting this set due to a RuntimeError
+				synchronized (this) {
+					fLoadThreadFinished = true;
+					notifyAll();
+				}
+				if (messageFile != null) {
+					try {
+						safeClose(messageFile);
+					} finally {
+						if (dtdFile != null)
+							safeClose(dtdFile);
+					}
+				}
+			}
+		}
+
+		private void safeClose(InputStream s) {
+			try {
+				s.close();
+			} catch (IOException e) {
+				/* ignore */
+			}
+		}
+	}
+
+
+
+	/**
+	 * Constructor to use for lazy loading of a system message file.
+	 *
+	 * The difference between the {@link #SystemMessageFile(String,InputStream,InputStream)}
+	 * constructor and this one is that the former loads the message file synchronously while
+	 * this one loads the message file in a thread.  The message file and DTD URLs are passed
+	 * in here so that the opening of their input streams can be deferred until the time when
+	 * the worker thread is started and able to load the message file.
+	 *
+	 * @param messageFileName the name of the system message file
+	 * @param msgFileURL the URL to the message file
+	 * @param dtdURL the URL to the DTD for the message file
+	 *
+	 * @since 3.1
+	 */
+	public SystemMessageFile(final String messageFileName, final URL msgFileURL, final URL dtdURL)
 	{
 		// have we already loaded this message file?
 		msgFile = getFromCache(messageFileName);
-		
+		if (msgFile == null){
-		// now, we haven't. Load it now.		
+			// will set msgFile variable and fLoadThreadFinished when done
+			fLoadThread = new LoadThread(messageFileName, msgFileURL, dtdURL);
+			fLoadThread.start();
+		}
+		else { // there's already a cached message file for this
+			// no need to load it, just use the msgFile
+			fLoadThread = null;
+		}
+	}
+
+
+	/**
+	 * Constructor
+	 * @param messageFileName - a key used to determine if a message file has already been loaded.
+	 * Usually the name of the xml file containing the message file.
+	 * @param messageFile the stream containing the message file.
+	 * @param dtdStream the stream containing the dtd for this message file.
+	 */
+	public SystemMessageFile (String messageFileName, InputStream messageFile, InputStream dtdStream)
+	{
+		// have we already loaded this message file?
+		msgFile = getFromCache(messageFileName);
+
+		// now, we haven't. Load it now.
 		this.dtdInputStream = dtdStream;
-		if (msgFile == null) 
+		if (msgFile == null)
 		{
 			Document doc = loadAndParseXMLFile(messageFile);
 			msgFile=new MessageFileInfo(messageFileName.toUpperCase(), messageFileName, doc);
 			msgfList.add(msgFile);
 			//scanForDuplicates(); // don't keep this for production. Too expensive
-		}		
+		}
+		fLoadThread = null;
 	}
 
 	/**
 	 * If the named message file has already been loaded return its
 	 * MessageFileInfo
-	 * @param messageFileName
+	 * @param messageFileName name of the message file
 	 * @return the MessageFileInfo for this message file
 	 */
 	protected MessageFileInfo getFromCache(String messageFileName)
 	{
-		for (int i=0; i<msgfList.size(); i++) 
+		for (int i=0; i<msgfList.size(); i++)
 		{
 			MessageFileInfo msgf=(MessageFileInfo)msgfList.get(i);
-			if (msgf.getMessageFullFileName().equals(messageFileName.toUpperCase())) 
+			if (msgf.getMessageFullFileName().equals(messageFileName.toUpperCase()))
 			{
 				return msgf;
 			}
@@ -150,33 +260,57 @@ public class SystemMessageFile implements ErrorHandler
 		return null;
 	}
 
+	/**
+	 * Waits until the message file is loaded or canceled due to error
+	 */
+	private void waitUntilLoaded() {
+		// fastpath: returns immediately if constructed synchronously
+		if (fLoadThread != null) {
+			// asynchronous load pending: wait until loaded or load canceled
+			synchronized (fLoadThread) {
+				while (!fLoadThreadFinished) {
+					try {
+						fLoadThread.wait();
+					} catch (InterruptedException e) {
+						// ignore since the Thread is guaranteed to finish
+					}
+				}
+			}
+		}
+	}
 
 	/**
-	 * Use this method to retrieve a message from the message file.
+	 * Use this method to retrieve a message from the message file. If this
-	 * @param msgId - the ID of the message to retrieve. This is the concatenation of the 
+	 * SystemMessageFile loaded from a thread, then the method will wait until
-	 *   message's component abbreviation, subcomponent abbreviation, and message ID as declared
+	 * the loading is complete before returning the message.
-	 *   in the message xml file.
+	 *
-	 * @return SystemMessage object
+	 * @param msgId - the ID of the message to retrieve. This is the
+	 *            concatenation of the message's component abbreviation,
+	 *            subcomponent abbreviation, and message ID as declared in the
+	 *            message XML file.
+	 * @return SystemMessage the SysteMessage object that corresponds to the
+	 *         message ID
 	 */
-	public SystemMessage getMessage(String msgId) 
+	public SystemMessage getMessage(String msgId)
 	{
+		waitUntilLoaded();
 		boolean echoErrorsToStandardOut = true;
 		// DY Defect 42605
-		if (msgFile.getXMLDocument() == null) 
+		if (msgFile == null || msgFile.getXMLDocument() == null)
 	    {
-	    	issueErrorMessage("No XML document for message file", echoErrorsToStandardOut); //$NON-NLS-1$
+	    	issueErrorMessage("No XML document for message file", echoErrorsToStandardOut);
             return null;
 	    }
-			
+
 	    // caching added by Phil to increase performance, and not to leave a trail of SystemMessage objects for
 	    //  the garbage collector. Hopefully, the extra memory for the cache does not defeat these benefits.
-	    SystemMessage msg = (SystemMessage)messages.get(msgFile.getMessageShortFileName()+":"+msgId); //$NON-NLS-1$
+		SystemMessage msg = (SystemMessage) messages.get(msgId);
 	    if (msg != null)
 	    {
 	    	//System.out.println("Reusing msg " + msgId);
 	        return msg;
 	    }
-	    
+
 	    // I guess the following line of code implies we only support a single component per message file... phil.
 	    // Code tweaked by Phil.
         //String componentAbbr=msgFile.getXMLDocument().getElementsByTagName("Component").item(0).getAttributes().getNamedItem("Abbr").getFirstChild().getNodeValue();
@@ -186,27 +320,27 @@ public class SystemMessageFile implements ErrorHandler
 	    NodeList componentElementList = msgFile.getXMLDocument().getElementsByTagName(XML_TAG_COMPONENT);
 	    if ((componentElementList == null) || (componentElementList.getLength() == 0))
 	    {
-	    	issueErrorMessage("Unable to find any Component elements",echoErrorsToStandardOut); //$NON-NLS-1$
+	    	issueErrorMessage("Unable to find any Component elements",echoErrorsToStandardOut);
             return null;
 	    }
 
 	    Element componentElement = (Element)componentElementList.item(0);
         String componentAbbr = componentElement.getAttribute(XML_ATTR_ABBR);
-        
+
         // get list of all Subcomponent elements...
         NodeList subComponentList=msgFile.getXMLDocument().getElementsByTagName(XML_TAG_SUBCOMPONENT);
-        
+
         if ((subComponentList == null) || (subComponentList.getLength() == 0))
         {
-	    	issueErrorMessage("Unable to find any Subcomponent elements",echoErrorsToStandardOut); //$NON-NLS-1$
+	    	issueErrorMessage("Unable to find any Subcomponent elements",echoErrorsToStandardOut);
             return null;
         }
-          
+
         // fold given msg ID to uppercase
-        msgId = msgId.toUpperCase();                
+        msgId = msgId.toUpperCase();
-        
+
         // search for the right component/subcomponent match
-        for (int subComponentIdx=0; subComponentIdx<subComponentList.getLength(); subComponentIdx++) 
+        for (int subComponentIdx=0; subComponentIdx<subComponentList.getLength(); subComponentIdx++)
         {
         	//String subComponentAbbr=subComponentList.item(subComponentIdx).getAttributes().getNamedItem("Abbr").getFirstChild().getNodeValue();
         	Element subComponentElement = (Element)subComponentList.item(subComponentIdx);
@@ -216,23 +350,23 @@ public class SystemMessageFile implements ErrorHandler
         	char msgIndicator=' ';
         	String msgL1=""; //$NON-NLS-1$
         	String msgL2=""; //$NON-NLS-1$
-        		
+
         	// if the message prefix matches, then try to find the message
         	//if (msgPrefix.toUpperCase().equals(msgId.toUpperCase().substring(0,msgPrefix.length())) &&
         	//if (msgPrefix.equals(msgId.substring(0,msgPrefix.length())) &&
         	if (msgId.startsWith(msgPrefix) &&
-        		Character.isDigit(msgId.charAt(msgPrefix.length()))) 
+        		Character.isDigit(msgId.charAt(msgPrefix.length())))
         	{
         		//String msgNumber=msgId.toUpperCase().substring(msgPrefix.length());
         		String msgNumber=msgId.substring(msgPrefix.length());
         		Element messageListNode=null;
-        		
+
         		// search for the message list node
         		/*
         		for (Node node=subComponentList.item(subComponentIdx).getFirstChild();
         		     node!=null; node=node.getNextSibling())
         		{
-        		     if (node.getNodeName().equals("MessageList")) 
+        		     if (node.getNodeName().equals("MessageList"))
         		     {
         		     	messageListNode=node;
         		     	break;
@@ -243,17 +377,17 @@ public class SystemMessageFile implements ErrorHandler
         		  messageListNode = (Element)msgListNodes.item(0);
         		else
         		{
-	    	        issueWarningMessage("unable to find MessageList nodes for subComponent " + subComponentElement.getAttribute(XML_ATTR_NAME),echoErrorsToStandardOut); //$NON-NLS-1$
+	    	        issueWarningMessage("unable to find MessageList nodes for subComponent " + subComponentElement.getAttribute(XML_ATTR_NAME),echoErrorsToStandardOut);
         			continue;
         		}
-        			     
+
         		// search for the message node which has the right number
         		//for (Node node=messageListNode.getFirstChild();
         		//     node!=null; node=node.getNextSibling())
         		NodeList msgNodes = messageListNode.getElementsByTagName(XML_TAG_MESSAGE);
         		if ((msgNodes==null) || (msgNodes.getLength()==0))
         		{
-	    	        issueWarningMessage("unable to find Message nodes for subComponent " + subComponentElement.getAttribute(XML_ATTR_NAME),echoErrorsToStandardOut); //$NON-NLS-1$
+	    	        issueWarningMessage("unable to find Message nodes for subComponent " + subComponentElement.getAttribute(XML_ATTR_NAME),echoErrorsToStandardOut);
         			continue;
         		}
         		boolean match = false; // I added this so we stop looping when we find what we are looking for!!! Phil.
@@ -261,8 +395,8 @@ public class SystemMessageFile implements ErrorHandler
         		{
         			 Element node = (Element)msgNodes.item(msgIdx);
         		     // if the message number matches...
-        		     //if (node.getNodeName().equals("Message") && node.getAttributes().getNamedItem("ID").getFirstChild().getNodeValue().toUpperCase().equals(msgNumber)) 
+        		     //if (node.getNodeName().equals("Message") && node.getAttributes().getNamedItem("ID").getFirstChild().getNodeValue().toUpperCase().equals(msgNumber))
-        		     if (node.getAttribute(XML_ATTR_ID).equals(msgNumber)) 
+        		     if (node.getAttribute(XML_ATTR_ID).equals(msgNumber))
         		     {
         		     	match = true;
         		     	// save the indicator value
@@ -270,18 +404,18 @@ public class SystemMessageFile implements ErrorHandler
         		     	msgIndicator=node.getAttribute(XML_ATTR_INDICATOR).toUpperCase().charAt(0);
         		     	// search for the l1 & l2 text
         		     	for (Node msgNode=node.getFirstChild();
-        		     	     msgNode!=null; msgNode=msgNode.getNextSibling()) 
+        		     	     msgNode!=null; msgNode=msgNode.getNextSibling())
         		     	{
-        		     	     // get Level One text	
+        		     	     // get Level One text
-        		     	     if (msgNode.getNodeName().equals(XML_TAG_LEVELONE)) 
+        		     	     if (msgNode.getNodeName().equals(XML_TAG_LEVELONE))
         		     	     	msgL1 = getNodeText(msgNode);
-        		     	     // get Level Two text	
+        		     	     // get Level Two text
-        		     	     else if (msgNode.getNodeName().equals(XML_TAG_LEVELTWO)) 
+        		     	     else if (msgNode.getNodeName().equals(XML_TAG_LEVELTWO))
         		     	     	msgL2 = getNodeText(msgNode);
         		     	}
-	        		    break;	
+	        		    break;
         		     }
-        		}        		
+        		}
         		if (!match)
         		{
         			/** TODO - DKM move this somewhere else since system message now needs to be eclipse independent
@@ -289,24 +423,15 @@ public class SystemMessageFile implements ErrorHandler
         			*/
         			return null;
         		}
-        		try 
+
-        		{   
+		       	msg = loadSystemMessage(componentAbbr, subComponentAbbr, msgNumber, msgIndicator, msgL1, msgL2);
-		       		msg = loadSystemMessage(componentAbbr, subComponentAbbr, msgNumber, msgIndicator, msgL1, msgL2);
+				messages.put(msgId, msg); // add to cache so we find it immediately next time!!
-		       		messages.put(msgFile.getMessageShortFileName()+":"+msgId, msg); // add to cache so we find it immediately next time!! //$NON-NLS-1$
+		       	return msg;
-		       		return msg;
-        		}
-        		catch (IndicatorException e) 
-        		{
-        			/** TODO - DKM move this somewhere else since system message now needs to be eclipse independent
-        			SystemBasePlugin.logError("MessageFile:getMessage: "+e.toString(), e);
-        			*/
-        		}
-       			break;
         	}
        	}
 		return null;
 	}
-	
+
 	/**
 	 * Override this to provide different extended SystemMessage implementation
 	 * @param componentAbbr a three letter component name
@@ -316,15 +441,14 @@ public class SystemMessageFile implements ErrorHandler
 	 * @param msgL1 the first level text that describes the error
 	 * @param msgL2 the second level text that provides details about the error and possible recovery
 	 * @return the SystemMessage
-	 * @throws IndicatorException if the message type indicator is invalid.
 	 * @see SystemMessage for message type indicator constants
 	 */
 	protected SystemMessage loadSystemMessage(String componentAbbr, String subComponentAbbr, String msgNumber, char msgIndicator,
-			String msgL1, String msgL2) throws IndicatorException
+			String msgL1, String msgL2)
 	{
 		return new SystemMessage(componentAbbr, subComponentAbbr, msgNumber, msgIndicator, msgL1, msgL2);
 	}
-	
+
 	/**
 	 * Get the level one text
 	 */
@@ -332,11 +456,11 @@ public class SystemMessageFile implements ErrorHandler
 	{
 		String nodeText = ""; //$NON-NLS-1$
 		for (Node textNode=msgNode.getFirstChild();
-        	 textNode!=null; textNode=textNode.getNextSibling())  
+        	 textNode!=null; textNode=textNode.getNextSibling())
         {
             if ((textNode.getNodeType()==Node.TEXT_NODE) && (textNode.getNodeValue().trim().length()>0))
         	   nodeText += textNode.getNodeValue();
-      	}  
+      	}
 		return nodeText.trim();
 	}
 
@@ -346,50 +470,51 @@ public class SystemMessageFile implements ErrorHandler
 	 * log file.
 	 * @return true if duplicates found.
 	 */
-	public boolean scanForDuplicates() 
+	public boolean scanForDuplicates()
 	{
 		boolean echoErrorsToStandardOut = true;
-		if (msgFile.getXMLDocument() == null) 
+		waitUntilLoaded();
-	    	return issueErrorMessage("No XML document for message file", echoErrorsToStandardOut); //$NON-NLS-1$
+		if (msgFile == null || msgFile.getXMLDocument() == null)
-			
+	    	return issueErrorMessage("No XML document for message file", echoErrorsToStandardOut);
+
         // parse out the Abbr attr of the first Component element
 	    NodeList componentElementList = msgFile.getXMLDocument().getElementsByTagName(XML_TAG_COMPONENT);
 	    if ((componentElementList == null) || (componentElementList.getLength() == 0))
-	    	return issueErrorMessage("Unable to find any Component elements",echoErrorsToStandardOut); //$NON-NLS-1$
+	    	return issueErrorMessage("Unable to find any Component elements",echoErrorsToStandardOut);
 
 	    Element componentElement = (Element)componentElementList.item(0);
         String componentAbbr = componentElement.getAttribute(XML_ATTR_ABBR);
-        
+
         // get list of all Subcomponent elements...
         NodeList subComponentList=msgFile.getXMLDocument().getElementsByTagName(XML_TAG_SUBCOMPONENT);
-        
+
         if ((subComponentList == null) || (subComponentList.getLength() == 0))
-	    	return issueErrorMessage("Unable to find any Subcomponent elements",echoErrorsToStandardOut); //$NON-NLS-1$
+	    	return issueErrorMessage("Unable to find any Subcomponent elements",echoErrorsToStandardOut);
-                  
+
         // scan all subcomponents...
         boolean anyDupes = false;
-        for (int subComponentIdx=0; subComponentIdx<subComponentList.getLength(); subComponentIdx++) 
+        for (int subComponentIdx=0; subComponentIdx<subComponentList.getLength(); subComponentIdx++)
         {
         	Element subComponentElement = (Element)subComponentList.item(subComponentIdx);
         	String subComponentAbbr = subComponentElement.getAttribute(XML_ATTR_ABBR);
         	String msgPrefix = (componentAbbr + subComponentAbbr).toUpperCase();
         	Vector msgsById = new Vector();
-        		
+
         	// search for the message list node
-        	Element messageListNode=null;        		
+        	Element messageListNode=null;
         	NodeList msgListNodes = subComponentElement.getElementsByTagName(XML_TAG_MESSAGeList);
         	if ((msgListNodes!=null) && (msgListNodes.getLength()>0))
         	  messageListNode = (Element)msgListNodes.item(0);
         	else
         	{
-	    	    issueWarningMessage("unable to find MessageList nodes for subComponent " + subComponentElement.getAttribute(XML_ATTR_NAME),echoErrorsToStandardOut); //$NON-NLS-1$
+	    	    issueWarningMessage("unable to find MessageList nodes for subComponent " + subComponentElement.getAttribute(XML_ATTR_NAME),echoErrorsToStandardOut);
         		continue;
         	}
-        			     
+
         	NodeList msgNodes = messageListNode.getElementsByTagName(XML_TAG_MESSAGE);
         	if ((msgNodes==null) || (msgNodes.getLength()==0))
         	{
-	    	        issueWarningMessage("unable to find Message nodes for subComponent " + subComponentElement.getAttribute(XML_ATTR_NAME),echoErrorsToStandardOut); //$NON-NLS-1$
+	    	        issueWarningMessage("unable to find Message nodes for subComponent " + subComponentElement.getAttribute(XML_ATTR_NAME),echoErrorsToStandardOut);
         			continue;
         	}
             for (int msgIdx = 0; (msgIdx < msgNodes.getLength()); msgIdx++)
@@ -399,7 +524,7 @@ public class SystemMessageFile implements ErrorHandler
         		 if (msgsById.contains(msgId))
         		 {
         		 	anyDupes = true;
-	    	        issueWarningMessage("Warning: duplicate message " + msgId + " found", echoErrorsToStandardOut); //$NON-NLS-1$ //$NON-NLS-2$
+	    	        issueWarningMessage("Warning: duplicate message " + msgId + " found", echoErrorsToStandardOut);
         		 }
         		 else
         		   msgsById.addElement(msgId);
@@ -414,25 +539,26 @@ public class SystemMessageFile implements ErrorHandler
 	 * @param fullFileName - the fully qualified name of the file to write to. Overwrites current contents.
 	 * @return true if it went well, false if it failed for some reason, such as given a bad file name. Errors written to standard out.
 	 */
-	public boolean printHTML(String fullFileName) 
+	public boolean printHTML(String fullFileName)
 	{
 		boolean echoErrorsToStandardOut = true;
-		if (msgFile.getXMLDocument() == null) 
+		waitUntilLoaded();
-	    	return issueErrorMessage("No XML document for message file", echoErrorsToStandardOut); //$NON-NLS-1$
+		if (msgFile == null || msgFile.getXMLDocument() == null)
-		
+	    	return issueErrorMessage("No XML document for message file", echoErrorsToStandardOut);
+
         // parse out the Abbr attr of the first Component element
 	    NodeList componentElementList = msgFile.getXMLDocument().getElementsByTagName(XML_TAG_COMPONENT);
 	    if ((componentElementList == null) || (componentElementList.getLength() == 0))
-	    	return issueErrorMessage("Unable to find any Component elements",echoErrorsToStandardOut); //$NON-NLS-1$
+	    	return issueErrorMessage("Unable to find any Component elements",echoErrorsToStandardOut);
 
 	    Element componentElement = (Element)componentElementList.item(0);
         String componentAbbr = componentElement.getAttribute(XML_ATTR_ABBR);
-        
+
         // get list of all Subcomponent elements...
         NodeList subComponentList=msgFile.getXMLDocument().getElementsByTagName(XML_TAG_SUBCOMPONENT);
-        
+
         if ((subComponentList == null) || (subComponentList.getLength() == 0))
-	    	return issueErrorMessage("Unable to find any Subcomponent elements",echoErrorsToStandardOut); //$NON-NLS-1$
+	    	return issueErrorMessage("Unable to find any Subcomponent elements",echoErrorsToStandardOut);
 
 		File outFile = new File(fullFileName);
 		PrintWriter outFileStream = null;
@@ -454,11 +580,11 @@ public class SystemMessageFile implements ErrorHandler
 		}
 		catch (IOException exc)
 		{
-			return issueErrorMessage("Unable to open given html file in printHTML: " + exc.getMessage(), echoErrorsToStandardOut); //$NON-NLS-1$
+			return issueErrorMessage("Unable to open given html file in printHTML: " + exc.getMessage(), echoErrorsToStandardOut);
 		}
 
         // pre-scan all subcomponents...
-        for (int subComponentIdx=0; subComponentIdx<subComponentList.getLength(); subComponentIdx++) 
+        for (int subComponentIdx=0; subComponentIdx<subComponentList.getLength(); subComponentIdx++)
         {
         	Element subComponentElement = (Element)subComponentList.item(subComponentIdx);
         	String subComponentAbbr = subComponentElement.getAttribute(XML_ATTR_ABBR);
@@ -473,27 +599,27 @@ public class SystemMessageFile implements ErrorHandler
 	    outFileStream.println("</TABLE>"); //$NON-NLS-1$
 
         // scan all subcomponents...
-        for (int subComponentIdx=0; subComponentIdx<subComponentList.getLength(); subComponentIdx++) 
+        for (int subComponentIdx=0; subComponentIdx<subComponentList.getLength(); subComponentIdx++)
         {
         	Element subComponentElement = (Element)subComponentList.item(subComponentIdx);
         	String subComponentAbbr = subComponentElement.getAttribute(XML_ATTR_ABBR);
         	String msgPrefix = (componentAbbr + subComponentAbbr).toUpperCase();
-        		
+
         	// search for the message list node
-        	Element messageListNode=null;        		
+        	Element messageListNode=null;
         	NodeList msgListNodes = subComponentElement.getElementsByTagName(XML_TAG_MESSAGeList);
         	if ((msgListNodes!=null) && (msgListNodes.getLength()>0))
         	  messageListNode = (Element)msgListNodes.item(0);
         	else
         	{
-	    	    issueWarningMessage("unable to find MessageList nodes for subComponent " + subComponentElement.getAttribute(XML_ATTR_NAME),echoErrorsToStandardOut); //$NON-NLS-1$
+	    	    issueWarningMessage("unable to find MessageList nodes for subComponent " + subComponentElement.getAttribute(XML_ATTR_NAME),echoErrorsToStandardOut);
         		continue;
         	}
-        			     
+
         	NodeList msgNodes = messageListNode.getElementsByTagName(XML_TAG_MESSAGE);
         	if ((msgNodes==null) || (msgNodes.getLength()==0))
         	{
-	    	        issueWarningMessage("unable to find Message nodes for subComponent " + subComponentElement.getAttribute(XML_ATTR_NAME),echoErrorsToStandardOut); //$NON-NLS-1$
+	    	        issueWarningMessage("unable to find Message nodes for subComponent " + subComponentElement.getAttribute(XML_ATTR_NAME),echoErrorsToStandardOut);
         			continue;
         	}
         	if (subComponentIdx > 0)
@@ -504,32 +630,32 @@ public class SystemMessageFile implements ErrorHandler
         	{
         		 Element node = (Element)msgNodes.item(msgIdx);
         		 String msgId = msgPrefix + node.getAttribute(XML_ATTR_ID);
-        		 char msgIndicator=node.getAttribute(XML_ATTR_INDICATOR).toUpperCase().charAt(0);        		 
+        		 char msgIndicator=node.getAttribute(XML_ATTR_INDICATOR).toUpperCase().charAt(0);
         		 String msgSeverity = "Unknown"; //$NON-NLS-1$
         		 if (msgIndicator == SystemMessage.ERROR)
-        		   msgSeverity = "Error"; //$NON-NLS-1$
+        		   msgSeverity = "Error";
         		 else if (msgIndicator == SystemMessage.WARNING)
-        		   msgSeverity = "Warning"; //$NON-NLS-1$
+        		   msgSeverity = "Warning";
         		 else if (msgIndicator == SystemMessage.INQUIRY)
-        		   msgSeverity = "Question"; //$NON-NLS-1$
+        		   msgSeverity = "Question";
         		 else if (msgIndicator == SystemMessage.INFORMATION)
-        		   msgSeverity = "Information"; //$NON-NLS-1$
+        		   msgSeverity = "Information";
         		 else if (msgIndicator == SystemMessage.COMPLETION)
-         		   msgSeverity = "Completion"; //$NON-NLS-1$
+         		   msgSeverity = "Completion";
         		 else if (msgIndicator == SystemMessage.UNEXPECTED)
-        		   msgSeverity = "Unexpected"; //$NON-NLS-1$
+        		   msgSeverity = "Unexpected";
-        		   
+
         		 String msgL1 = ""; //$NON-NLS-1$
         		 String msgL2 = ""; //$NON-NLS-1$
         		 // search for the l1 & l2 text
         		 for (Node msgNode=node.getFirstChild();
-        		      msgNode!=null; msgNode=msgNode.getNextSibling()) 
+        		      msgNode!=null; msgNode=msgNode.getNextSibling())
         		 {
-        		     // get Level One text	
+        		     // get Level One text
-        		     if (msgNode.getNodeName().equals(XML_TAG_LEVELONE)) 
+        		     if (msgNode.getNodeName().equals(XML_TAG_LEVELONE))
         		       	msgL1 = getNodeText(msgNode);
-        		     // get Level Two text	
+        		     // get Level Two text
-        		     else if (msgNode.getNodeName().equals(XML_TAG_LEVELTWO)) 
+        		     else if (msgNode.getNodeName().equals(XML_TAG_LEVELTWO))
         		      	msgL2 = getNodeText(msgNode);
         		 }
 			     outFileStream.println("<H3>"+msgId+"</H3>"); //$NON-NLS-1$ //$NON-NLS-2$
@@ -543,19 +669,19 @@ public class SystemMessageFile implements ErrorHandler
 	    outFileStream.close();
 		return true;
 	}
-	
+
 	/**
 	 * Issue an error message
 	 */
 	private boolean issueErrorMessage(String errormsg, boolean echoStandardOut)
 	{
-	
+
 		/** TODO - DKM move this somewhere else since system message now needs to be eclipse independent
 		 *
-        SystemBasePlugin.logError("MessageFile error for msg file " + msgFile.getMessageShortFileName() + ": " + errormsg);        
+        SystemBasePlugin.logError("MessageFile error for msg file " + msgFile.getMessageShortFileName() + ": " + errormsg);
         **/
         if (echoStandardOut)
-          System.out.println("MessageFile error for msg file " + msgFile.getMessageShortFileName() + ": " + errormsg); //$NON-NLS-1$ //$NON-NLS-2$
+          System.out.println("MessageFile error for msg file " + msgFile.getMessageShortFileName() + ": " + errormsg);
         return false;
 	}
 	/**
@@ -564,13 +690,13 @@ public class SystemMessageFile implements ErrorHandler
 	private boolean issueWarningMessage(String errormsg, boolean echoStandardOut)
 	{
 			/** TODO - DKM move this somewhere else since system message now needs to be eclipse independent
-        SystemBasePlugin.logError("MessageFile warning for msg file " + msgFile.getMessageShortFileName() + ": " + errormsg);        
+        SystemBasePlugin.logError("MessageFile warning for msg file " + msgFile.getMessageShortFileName() + ": " + errormsg);
         */
         if (echoStandardOut)
-          System.out.println("MessageFile warning for msg file " + msgFile.getMessageShortFileName() + ": " + errormsg); //$NON-NLS-1$ //$NON-NLS-2$
+          System.out.println("MessageFile warning for msg file " + msgFile.getMessageShortFileName() + ": " + errormsg);
         return false;
 	}
-	
+
 	/**
 	 * Create the XML parser
 	 * Set its entity resolver and error handler.
@@ -591,11 +717,11 @@ public class SystemMessageFile implements ErrorHandler
 			return null;
 		}
 //		DOMParser parser=new DOMParser();
-//		  try 
+//		  try
 //		  {
 //			 parser.setFeature( "http://xml.org/sax/features/validation", true);
 //		  }
-//		  catch (SAXNotRecognizedException e) 
+//		  catch (SAXNotRecognizedException e)
 //		  {
 //			// the feature was not recognized
 //				/** TODO - DKM move this somewhere else since system message now needs to be eclipse independent
@@ -603,7 +729,7 @@ public class SystemMessageFile implements ErrorHandler
 //			*/
 //			 return null;
 //		  }
-//		  catch (SAXNotSupportedException e) 
+//		  catch (SAXNotSupportedException e)
 //		  {
 //			// the feature requested was not supported
 //				/** TODO - DKM move this somewhere else since system message now needs to be eclipse independent
@@ -612,15 +738,15 @@ public class SystemMessageFile implements ErrorHandler
 //			return null;
 //		  }
 		parser.setEntityResolver(new EntityResolver() {
-			public InputSource resolveEntity(String publicId, String systemId) throws SAXException, java.io.IOException 
+			public InputSource resolveEntity(String publicId, String systemId) throws SAXException, java.io.IOException
 			{
 				/*
 				// This code does not work with fragments
 				Path path = new Path(systemId);
-				if (systemId.toUpperCase().endsWith("MESSAGEFILE.DTD")) 
+				if (systemId.toUpperCase().endsWith("MESSAGEFILE.DTD"))
 				{
-					if (SystemPlugin.getBaseDefault().getDescriptor().find(path)==null) 
+					if (SystemPlugin.getBaseDefault().getDescriptor().find(path)==null)
-					{ 
+					{
 						path = new Path("messageFile.dtd");
 					}
 				}
@@ -630,7 +756,7 @@ public class SystemMessageFile implements ErrorHandler
 				if (dtdInputStream != null)
 				{
 					return new InputSource(dtdInputStream);
-				} 
+				}
 				else // if we have the directory containing the DTD use that
 				{
 					// yantzi:artemis6.2 changed to use URI instead of URL (URIs handle the spaces)
@@ -650,66 +776,66 @@ public class SystemMessageFile implements ErrorHandler
 					{
 						// ignore and continue
 					}
-					
+
 					return new InputSource(systemId);
 				}
-			}        
+			}
 		});
 		parser.setErrorHandler(this);
 		return parser;
 	}
 	/**
-	 * loadAndParseXMLFile: 
+	 * loadAndParseXMLFile:
 	 * tries to load and parse the specified XML file .
 	 * @param String messageFile:	InputStream containing the XML file
 	 */
-	private Document loadAndParseXMLFile (InputStream messageFile) 
+	private Document loadAndParseXMLFile (InputStream messageFile)
 	{
         DocumentBuilder parser = createXmlParser();
-		try 
+		try
 		{
 		   InputSource in = new InputSource(messageFile);
-		   
+
 		   // DKM - hack!
 		   //   If systemId is null for the InputSource, then
 		   //   the current parser hits a fatal exception.
 		   //   This hack prevents that exception so that the
 		   //   specified EntityResolver will get used.
 		   in.setSystemId("foo"); //$NON-NLS-1$
-		   Document document = parser.parse(in); 
+		   Document document = parser.parse(in);
-		   
+
 		   //Document document = parser.parse(messageFile);
 		   return document;
 		}
-		catch (SAXException e) 
+		catch (SAXException e)
 		{
 			e.printStackTrace();
 			// the parser was unable to parse the file.
 			return null;
 		}
-		catch (IOException e) 
+		catch (IOException e)
 		{
 			e.printStackTrace();
 				/** TODO - DKM move this somewhere else since system message now needs to be eclipse independent
-			*/		    
+			*/
 			return null;
-		}			    
+		}
 	}
-	
+
-	/** 
+	/**
-	 * XML Parser-required method: XML-parser warning. 
+	 * XML Parser-required method: XML-parser warning.
 	 */
-   public void warning(SAXParseException ex) 
+   public void warning(SAXParseException ex)
    {
    		/** TODO - DKM move this somewhere else since system message now needs to be eclipse independent
 		SystemBasePlugin.logError("SystemMessageFile: warning parsing message file: "+ex.toString());
 		*/
    }
 
-   /** 
+   /**
-    * XML Parser-required method: XML-parser Error. 
+    * XML Parser-required method: XML-parser Error.
     */
-   public void error(SAXParseException ex) 
+   public void error(SAXParseException ex)
    {
    		/** TODO - DKM move this somewhere else since system message now needs to be eclipse independent
 		SystemBasePlugin.logError("SystemMessageFile: Error parsing message file: "+ex.toString(), ex);
@@ -724,15 +850,15 @@ public class SystemMessageFile implements ErrorHandler
 		*/
    }
 
-   /** 
+	/**
-    * XML Parser-required method: XML-parser Fatal error. 
+	 * XML Parser-required method: XML-parser Fatal error.
-    */
+	 */
-   public void fatalError(SAXParseException ex) throws SAXException 
+	public void fatalError(SAXParseException ex) throws SAXException
-   {
+	{
-   		/** TODO - DKM move this somewhere else since system message now needs to be eclipse independent
+		/** TODO - DKM move this somewhere else since system message now needs to be eclipse independent
 		SystemBasePlugin.logError("SystemMessageFile: Fatal Error parsing message file: "+ex.toString(), ex);
 		*/
 		throw(ex);
-   }
+	}
-	
+
 }

rse/plugins/org.eclipse.rse.ui/META-INF/MANIFEST.MF

@@ -2,7 +2,7 @@ Manifest-Version: 1.0
 Bundle-ManifestVersion: 2
 Bundle-Name: %pluginName
 Bundle-SymbolicName: org.eclipse.rse.ui;singleton:=true
-Bundle-Version: 3.0.100.qualifier
+Bundle-Version: 3.1.0.qualifier
 Bundle-Activator: org.eclipse.rse.ui.RSEUIPlugin
 Bundle-Localization: plugin
 Require-Bundle: org.eclipse.core.runtime,
@@ -14,7 +14,7 @@ Require-Bundle: org.eclipse.core.runtime,
  org.eclipse.ui.ide,
  org.eclipse.ui.views,
  org.eclipse.ui.workbench.texteditor,
- org.eclipse.rse.services;bundle-version="[3.0.0,4.0.0)",
+ org.eclipse.rse.services;bundle-version="[3.1.0,4.0.0)",
  org.eclipse.rse.core;bundle-version="[3.0.0,4.0.0)"
 Import-Package: com.ibm.icu.lang,
  com.ibm.icu.text,

rse/plugins/org.eclipse.rse.ui/UI/org/eclipse/rse/ui/SystemBasePlugin.java

@@ -15,11 +15,11 @@
  * Martin Oberhuber (Wind River) - [168870] refactor org.eclipse.rse.core package of the UI plugin
  * David McKnight   (IBM)        - [243263] NPE on expanding a filter
  * David McKnight   (IBM)        - [244454] SystemBasePlugin.getWorkBench() incorrectly returns null when called during Eclipse startup
+ * David McKnight   (IBM)  [246406] [performance] Timeout waiting when loading SystemPreferencesManager$ModelChangeListener during startup
  ********************************************************************************/
 
 package org.eclipse.rse.ui;
 
-import java.io.InputStream;
 import java.net.URL;
 import java.util.Hashtable;
 import java.util.Locale;
@@ -302,9 +302,7 @@ public abstract class SystemBasePlugin extends AbstractUIPlugin
 		try {
 			URL url = resolveBundleNameNL(bundle, fileName);
 			if (url != null) {
-				InputStream messageFileStream = url.openStream();
+				mf = SystemUIMessageFile.getMessageFile(fileName, url);
-				mf = SystemUIMessageFile.getMessageFile(fileName, messageFileStream);
-				messageFileStream.close();
 				ok = true;
 			}
 		} catch (Throwable t) {
@@ -345,10 +343,8 @@ public abstract class SystemBasePlugin extends AbstractUIPlugin
 		boolean ok = false;
 		try {
 			URL url = bundle.getEntry("/"+fileName); //$NON-NLS-1$
-			if (url != null) {
+			if (url != null) { 
-				InputStream messageFileStream = url.openStream();
+				mf = SystemUIMessageFile.getMessageFile(fileName, url);
-				mf = SystemUIMessageFile.getMessageFile(fileName, messageFileStream);
-				messageFileStream.close();
 				ok = true;
 			}
 		} catch (Throwable t) {

rse/plugins/org.eclipse.rse.ui/UI/org/eclipse/rse/ui/messages/SystemUIMessageFile.java

@@ -1,5 +1,5 @@
 /********************************************************************************
- * Copyright (c) 2004, 2007 IBM Corporation and others. All rights reserved.
+ * Copyright (c) 2004, 2008 IBM Corporation and others. All rights reserved.
  * This program and the accompanying materials are made available under the terms
  * of the Eclipse Public License v1.0 which accompanies this distribution, and is 
  * available at http://www.eclipse.org/legal/epl-v10.html
@@ -12,6 +12,7 @@
  * 
  * Contributors:
  * Martin Oberhuber (Wind River) - [168870] refactor org.eclipse.rse.core package of the UI plugin
+ * David McKnight   (IBM)  [246406] [performance] Timeout waiting when loading SystemPreferencesManager$ModelChangeListener during startup
  ********************************************************************************/
 
 package org.eclipse.rse.ui.messages;
@@ -33,8 +34,8 @@ import org.eclipse.rse.ui.SystemBasePlugin;
 public class SystemUIMessageFile extends SystemMessageFile {
 	
 	/**
-	 * Factory method for constructing a SystemUIMessageFile. If an error occurs when
+	 * Factory method for constructing a SystemUIMessageFile that loads the message file synchronously. 
-	 * reading the message file DTD then that is logged.
+	 * If an error occurs when reading the message file DTD then that is logged.
 	 * @param messageFileName The "registered" name of the message file. Used to determine
 	 * if the message file has been loaded. 
 	 * @param messageFileStream The stream containing the message file. It is the
@@ -59,12 +60,57 @@ public class SystemUIMessageFile extends SystemMessageFile {
 		}
 		return result;
 	}
+	
+	/**
+	 * Factory method for constructing a SystemUIMessageFile that loads the message file in a thread.
+	 *  
+	 * The difference between {@link #getMessageFile(String,InputStream)} and this method
+	 * is that the former calls the constructor that loads the message file synchronously 
+	 * while this one loads the message file in a worker thread.  The message file URL is 
+	 * passed in here so that the opening of it's input stream can be deferred until the 
+	 * time when the worker thread is started and able to load the message file.
+	 * 
+	 * @param messageFileName The name of the message file to load. 
+	 * @param messageFileURL The URL to the message file.
+	 * @return The message file that was constructed.
+	 * 
+	 * @since 3.1
+	 */
+	public static SystemUIMessageFile getMessageFile(String messageFileName,
+			URL messageFileURL) {
+		SystemUIMessageFile result = null;
+		URL dtdURL = RSEUIPlugin.getDefault().getMessageFileDTD();
+		if (dtdURL != null) {
+			result = new SystemUIMessageFile(messageFileName,messageFileURL, dtdURL);
+		} else {
+			SystemBasePlugin.logError("Could not find mesage file DTD."); //$NON-NLS-1$
+		}
+		return result;
+	}
+	
 
+	/**
+	 * Constructor for synchronous loading of the message file.  
+	 * 
+	 * This is private because this is not to be called directly, but rather 
+	 * from {@link #getMessageFile(String, InputStream)}.
+	 */
 	private SystemUIMessageFile(String messageFileName,
 			InputStream messageFileStream, InputStream dtdStream) {
 		super(messageFileName, messageFileStream, dtdStream);
 	}
 
+	/**
+	 * Constructor for lazy loading of the message file.
+	 * 
+	 * This is private because this is not to be called directly, but rather 
+	 * from {@link #getMessageFile(String, URL)}.
+	 */
+	private SystemUIMessageFile(String messageFileName,
+			URL messageFileURL, URL dtdURL) {
+		super(messageFileName, messageFileURL, dtdURL);
+	}
+
 	/**
 	 * Override this to provide different extended SystemMessage implementation
 	 *