[RFC][plugin]: fix concurrency problems in PAV.java

[Deepak Bhole]

* Denis Lila <dlila at redhat.com> [2011-04-13 15:10]:
> > If a patch akin to
> > http://hg.openjdk.java.net/jdk6/jdk6/langtools/rev/5c2858bccb3f
> > goes in, I will not be responsible for my actions.
> 
> I definitely don't want that ;-).
> 
> Attached is the second patch. It's mostly cleanup, and it
> also uses "pav" in destroyApplet, instead of calling
> get(id) again and again.
> 
> Ok to push?
>

...
... 

<snip>
>  
>              PluginDebug.debug("getCachedImageRef() getting img from URL = ", url);
> @@ -910,8 +815,8 @@
>          SocketPermission panelSp =
>                  new SocketPermission(panel.getCodeBase().getHost(), "connect");
>          synchronized(appletPanels) {
> -            for (Enumeration e = appletPanels.elements(); e.hasMoreElements();) {
> -                AppletPanel p = (AppletPanel) e.nextElement();
> +            for (Enumeration<AppletPanel> e = appletPanels.elements(); e.hasMoreElements();) {
> +                AppletPanel p = e.nextElement();
>                  String param = p.getParameter("name");
>                  if (param != null) {
>                      param = param.toLowerCase();
> @@ -1591,15 +1496,15 @@
>           * at the same time.
>           */
>          try {
> -            panel.joinAppletThread();
> -            panel.release();
> +            ((AppletViewerPanel)panel).joinAppletThread();
> +            ((AppletViewerPanel)panel).release();
>          } catch (InterruptedException e) {
>              return; // abort the reload
>          }
>  
>          AccessController.doPrivileged(new PrivilegedAction<Void>() {
>              public Void run() {
> -                panel.createAppletThread();
> +                ((AppletViewerPanel)panel).createAppletThread();
>                  return null;
>              }


Instead of doing this, it would be easier to change the type of
appletPanels to Vector<AppletViewerPanel> , then the casting is not
needed as AVP inherits from AP.