looking for example of problems when accessing GUI items in non eventdispatch thread

[Alex Hunsley]

I'm looking for ideas for some test code that demonstrates that
accessing GUI items (in Swing) from a thread other than the event
dispatch thread leads to problems.
Ideally, I want to write a small app that does things the "bad way" and
ably (and repeatedly) demonstrates that a problem arises. Anyone have
any ideas of a way to do this?

The nearest parallel to the sort of thing I'm thinking of is the java
program on Sun's site that demonstrates that getting and putting items
into a cubbyhole, without appropriate sychronisation locks, results in
some items being not 'got' at all, or got more than one time....

thanks
alex

 

[Matt Humphrey]

I'm looking for ideas for some test code that demonstrates that
accessing GUI items (in Swing) from a thread other than the event
dispatch thread leads to problems.
Ideally, I want to write a small app that does things the "bad way" and
ably (and repeatedly) demonstrates that a problem arises. Anyone have
any ideas of a way to do this?

The nearest parallel to the sort of thing I'm thinking of is the java
program on Sun's site that demonstrates that getting and putting items
into a cubbyhole, without appropriate sychronisation locks, results in
some items being not 'got' at all, or got more than one time....

Just do it. Create a thread that changes the properties of any of the UI
elements. The more frequently threads change things the sooner you'll see
things messed up.

Cheers,
Matt Humphrey (e-mail address removed) http://www.iviz.com/

 

[Babu Kalakrishnan]

I'm looking for ideas for some test code that demonstrates that
accessing GUI items (in Swing) from a thread other than the event
dispatch thread leads to problems.
Ideally, I want to write a small app that does things the "bad way" and
ably (and repeatedly) demonstrates that a problem arises. Anyone have
any ideas of a way to do this?

Try adding and deleting rows from a JList or JTable periodically from
another thread. Sooner or later you are bound to get an
ArrayIndexOutOfBoundsException.