Posts Photos Archives About

We have a web screen with a number of applets that has a problem on Mac OSX 10.5.7, Firefox 3.0.15, java 1.5.0_19.

The problem is encountered on the user site. On initial load of applets (with an empty applet cache), the screen locks up/hangs while loading the applets. After refreshing the page, it loads normally. If the cache is cleared, same problem happens again.

Unfortunately, we're not encountering this on our local test machine (same OS, java and Firefox versions)

We were able to get a jstack thread dump, see below:

However, we're not sure how to interpret it. Any suggestions or advice?

Edit: We were able to replicate in our testing machine by creating a new user (clean Firefox profile). If we clear the java cache then visit the problematic pages, the edit controls are disabled (we can't click them to focus them), the Firefox address bar and search box have the same behavior. The edit box controls only "unfreeze" when we access the "Help" menu entry, which has a Search edit box that is active.


Pool said...

Looking at the thread dump there's a wait in a run method on your code.

Thread t@60419: (state = BLOCKED)
- java.lang.Object.wait(long) @bci=0 (Interpreted frame)
- OurApplet$ @bci=16, line=138 (Interpreted frame)

What is this wait for? Is it possible that it's a timing error on your applet?

Is it possible it's a Swing applet and calls invokeAndWait? If so I would recommend using invokeLater to build the Swing components as I have noticed that Opera can sporadically crash at start up with invokeAndWait.