Concurrent Modification Error

Douglas2 · October 3, 2011, 1:17pm

We’ve been seeing a concurrent modification error.

It seems to be happening on Window.java on this line…

[b]

for (String script : jsExecQueue) {
[/b]
target.startTag(“execJS”);
target.addAttribute(“script”, script);
target.endTag(“execJS”);
}

Philippe7 · October 3, 2011, 2:16pm

Funny, I just looked at this code today as I was trying to use Window.executeJavaScript() and it wasn’t working.
It appeared that I had a silly mistake in my JS and got no feedback on it (no error in the Firefox console, not sure why).

Do you use Window.executeJavaScript() in your program?

Henri2 · October 4, 2011, 7:01am

Douglas W Ferguson:

We’ve been seeing a concurrent modification error.

It seems to be happening on Window.java on this line…
    [b]
for (String script : jsExecQueue) {
[/b]
target.startTag(“execJS”);
target.addAttribute(“script”, script);
target.endTag(“execJS”);
}

The only way I can see that happening is if you have a background thread that does something to the jsExecQueue while the component is being painted - you are probably calling Window.executeJavaScript() from a background thread without synchronizing that call to the application instance.