Return-Path: 
 <dev-return-46498-apmail-cocoon-dev-archive=cocoon.apache.org@cocoon.apache.org>
Delivered-To: apmail-cocoon-dev-archive@cocoon.apache.org
Received: (qmail 76540 invoked by uid 500); 18 Aug 2003 08:18:05 -0000
Mailing-List: contact dev-help@cocoon.apache.org; run by ezmlm
Precedence: bulk
list-help: <mailto:dev-help@cocoon.apache.org>
list-unsubscribe: <mailto:dev-unsubscribe@cocoon.apache.org>
list-post: <mailto:dev@cocoon.apache.org>
Reply-To: dev@cocoon.apache.org
Delivered-To: mailing list dev@cocoon.apache.org
Received: (qmail 76513 invoked from network); 18 Aug 2003 08:18:04 -0000
Received: from unknown (HELO trinity.anyware-tech.com) (217.112.237.100)
  by daedalus.apache.org with SMTP; 18 Aug 2003 08:18:04 -0000
Received: (qmail 2002 invoked from network); 18 Aug 2003 08:18:08 -0000
Received: from unknown (HELO anyware-tech.com) (10.1.0.254)
  by trinity.anyware-tech.com with SMTP; 18 Aug 2003 08:18:08 -0000
Message-ID: <3F408BBF.6040109@anyware-tech.com>
Date: Mon, 18 Aug 2003 10:18:07 +0200
From: Sylvain Wallez <sylvain.wallez@anyware-tech.com>
Organization: Anyware Technologies
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US;
 rv:1.4) Gecko/20030624
X-Accept-Language: fr, en, en-us
MIME-Version: 1.0
To: dev@cocoon.apache.org
CC: dev@ant.apache.org
Subject: Re: [OT] Build Time
References: <3F3D5098.9000304@verizon.net> <bhjl0t$pol$1@sea.gmane.org>
 <m365kvphxb.fsf@bodewig.bost.de>
In-Reply-To: <m365kvphxb.fsf@bodewig.bost.de>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
X-Spam-Rating: daedalus.apache.org 1.6.2 0/1000/N

Stefan Bodewig wrote:

>On Fri, 15 Aug 2003, Nicola Ken Barozzi <nicolaken@apache.org> wrote:
>
>  
>
>>>DirectoryScanner.scandir Does somebody know anybody working on Ant
>>>logging system? Is Ant 1.6 better in this regard?
>>>      
>>>
>
>Ant's DirectoryScanner may have become a lot (and I mean a lot) faster
>in 1.6, depending on the patterns you use.
>
>  
>
>>>PS Removing synchronized() in this method gives even better
>>>results
>>>      
>>>
>
>We allow listeners to be added and removed during event logging and we
>may be running several tasks in <parallel>, so I'm afraid that
>removing synchronized may be doing more harm than help.
>
>For the same reason we clone the Vector of listeners before we start
>to fire events.  In the patched code, we'd at least have to copy the
>array and iterate over that copy to avoid problems when a listener
>removes itself in response to a logged message.
>  
>

To solve this problem, you may consider the fact that listeners are more 
often fired than changed, and therefore use a different pattern, which 
does the cloning and synchronisation when the listener list has to be 
changed, and not when it has to be traversed.

private List listenerers;

public void fireEvent(Event ev) {
  Iterator iter = this.listeners.iterator();
  while(iter.hasNext()) {
    ((EventListener)iter.next()).fireEvent(ev);
  }
}

public void synchronized addListener(EventListener evl) {
  // Make a local copy on which we will act : it avoids
  // ConcurrentModificationException if someone is executing fireEvent()
  List newListeners = this.listeners.clone();
  newListeners.add(evl);
  // and replace the listener list
  this.listeners = newListeners;
}

Sylvain

-- 
Sylvain Wallez                                  Anyware Technologies
http://www.apache.org/~sylvain           http://www.anyware-tech.com
{ XML, Java, Cocoon, OpenSource }*{ Training, Consulting, Projects }
Orixo, the opensource XML business alliance  -  http://www.orixo.com