/hg/release/icedtea6-1.8: Fix race conditions in plugin initiali...

[dbhole at icedtea.classpath.org]

changeset c691bc07c5e0 in /hg/release/icedtea6-1.8
details: http://icedtea.classpath.org/hg/release/icedtea6-1.8?cmd=changeset;node=c691bc07c5e0
author: Deepak Bhole <dbhole at redhat.com>
date: Wed Jul 14 17:42:26 2010 -0400

	Fix race conditions in plugin initialization code that were causing
	hangs when loading multiple applets in parallel.


diffstat:

3 files changed, 40 insertions(+), 3 deletions(-)
ChangeLog                                                        |   16 ++++++
plugin/icedteanp/java/sun/applet/PluginMessageConsumer.java      |   23 ++++++++--
plugin/icedteanp/java/sun/applet/PluginMessageHandlerWorker.java |    4 +

diffs (102 lines):

diff -r 595ea39174ab -r c691bc07c5e0 ChangeLog
--- a/ChangeLog	Wed Jul 14 00:06:12 2010 +0200
+++ b/ChangeLog	Wed Jul 14 17:42:26 2010 -0400
@@ -1,3 +1,19 @@ 2010-07-13  Matthias Klose  <doko at ubuntu
+2010-07-14  Deepak Bhole <dbhole at redhat.com>
+
+	* plugin/icedteanp/java/sun/applet/PluginMessageConsumer.java: Add a new
+	processedIds list to track which instances have been instantiated.
+	(okToProcess): Register width as priority only after handle is acquired.
+	Process resize messages only after tag and handle are processed.
+	(notifyWorkerIsFree): Add instance id to processedIds list if the worked
+	being free'd is an init worker.
+	(getFreeWorker): Create new normal worked only if worker count is less
+	than MAX_WORKERS - PRIORITY_WORKERS.
+	(dumpWorkerStatus): New method. Useful when debugging -- prints status of
+	all workers.
+	* plugin/icedteanp/java/sun/applet/PluginMessageHandlerWorker.java
+	(toString): New method. Returns the string representation of the worker
+	instance at call time.
+
 2010-07-13  Matthias Klose  <doko at ubuntu.com>
 
 	* acinclude.m4 (IT_CHECK_PLUGIN_DEPENDENCIES): Don't require libxul
diff -r 595ea39174ab -r c691bc07c5e0 plugin/icedteanp/java/sun/applet/PluginMessageConsumer.java
--- a/plugin/icedteanp/java/sun/applet/PluginMessageConsumer.java	Wed Jul 14 00:06:12 2010 +0200
+++ b/plugin/icedteanp/java/sun/applet/PluginMessageConsumer.java	Wed Jul 14 17:42:26 2010 -0400
@@ -61,6 +61,7 @@ class PluginMessageConsumer {
 	PluginStreamHandler streamHandler = null;
 	AppletSecurity as;
 	ConsumerThread consumerThread = new ConsumerThread();
+	private static ArrayList<Integer> processedIds = new ArrayList<Integer>();
 
 	/** 
 	 * Registers a reference to wait for. Responses to registered priority 
@@ -162,7 +163,6 @@ class PluginMessageConsumer {
 	        }
 	        
 	        registerPriorityWait("instance " + instanceNum + " handle");
-	        registerPriorityWait("instance " + instanceNum + " width");
 
 	    } else if (msgParts[2].equals("handle")) {
 	            Integer instanceNum = new Integer(msgParts[1]);
@@ -171,6 +171,16 @@ class PluginMessageConsumer {
 	            // Handle messages should NEVER go before tag messages
 	            if (!isInInit(instanceNum))
 	                return false;
+
+		        registerPriorityWait("instance " + instanceNum + " width");
+	    } else if (msgParts[2].equals("width")) {
+	    	
+	    	// width messages cannot proceed until handle and tag have been resolved
+	    	Integer instanceNum = new Integer(msgParts[1]);
+
+	    	if (!processedIds.contains(instanceNum)) {
+                return false;
+            }
 	    }
 
 	    return true;
@@ -181,8 +191,10 @@ class PluginMessageConsumer {
 	        Iterator<Integer> i = initWorkers.keySet().iterator();
             while (i.hasNext()) {
                 Integer key = i.next();
-                if (initWorkers.get(key).equals(worker))
+                if (initWorkers.get(key).equals(worker)) {
+                    processedIds.add(key);
                     initWorkers.remove(key);
+                }
             }
 	    }
 	    
@@ -270,7 +282,7 @@ class PluginMessageConsumer {
 			if (workers.size() <= MAX_WORKERS) {
 			    PluginMessageHandlerWorker worker = null;
 			    
-			    if (workers.size() <= (MAX_WORKERS - PRIORITY_WORKERS)) {
+			    if (workers.size() < (MAX_WORKERS - PRIORITY_WORKERS)) {
 			        PluginDebug.debug("Cannot find free worker, creating worker " + workers.size());
 			        worker = new PluginMessageHandlerWorker(this, streamHandler, workers.size(), as, false);
 			    } else if (prioritized) {
@@ -291,4 +303,9 @@ class PluginMessageConsumer {
 			return null;
 	}
 	
+	private void dumpWorkerStatus() {
+		for (PluginMessageHandlerWorker worker: workers) {
+			PluginDebug.debug(worker.toString());
+		}
+	}
 }
diff -r 595ea39174ab -r c691bc07c5e0 plugin/icedteanp/java/sun/applet/PluginMessageHandlerWorker.java
--- a/plugin/icedteanp/java/sun/applet/PluginMessageHandlerWorker.java	Wed Jul 14 00:06:12 2010 +0200
+++ b/plugin/icedteanp/java/sun/applet/PluginMessageHandlerWorker.java	Wed Jul 14 17:42:26 2010 -0400
@@ -140,4 +140,8 @@ class PluginMessageHandlerWorker extends
 	        return free && (prioritized == isPriorityWorker);
 	    }
 	}
+
+	public String toString() {
+		return "Worker #" + this.id + "/IsPriority=" + this.isPriorityWorker + "/IsFree=" + this.free + "/Message=" + message;  
+	}
 }