On Fri, 3 Feb 2023 07:27:39 GMT, Prasanta Sadhukhan <psadhuk...@openjdk.org> wrote:
>> SwingWorker done() method [spec >> ](https://github.com/openjdk/jdk/blob/master/src/java.desktop/share/classes/javax/swing/SwingWorker.java#L452) >> says "Executed on the Event Dispatch Thread after the doInBackground method >> is finished" >> but there's no mechanism in place to honor that claim. >> The >> [spec](https://github.com/openjdk/jdk/blob/master/src/java.desktop/share/classes/javax/swing/SwingWorker.java#L289) >> also says the state should be DONE after doInBackground() returns which is >> also not done. >> >> Modified the code to honour the specification. > > Prasanta Sadhukhan has updated the pull request incrementally with one > additional commit since the last revision: > > jcheck fix The more I think about it, the more I'm inclined towards this change may be unnecessary at all. Yet the spec needs to be updated. Consider the following scenario. The user starts a long running operation, so `doInBackground` is being executed. It may block access to UI and show the progress. Then they decide they don't to wait any more, so they cancel the operation by clicking *Cancel* button the UI which calls `cancel(true)` on `SwingWorker`. The thread that runs `doInBackground` is interrupted. It may not exit yet but *does it matter?* >From the user's point of view, the operation is already cancelled. That fact >that the background thread needs to perform some clean-up actions is >irrelevant. >From the developer's point of view, it does matter. It depends on what actions >are valid on this instance of `SwingWorker`. Until `doInBackground` finishes, >a resource may still be busy while it performs its clean-up. Can the clean-up be run in background too? There's no univocal answer to this question: in some cases, it can; in other cases, it cannot. Thus, with the current approach in this fix, `SwingWorker` provides stronger guarantees which are stated in the spec that `done` is called only after `doInBackground` finishes whether it's cancelled or not. Before this fix, the guarantee was that the call to `get` doesn't block when `done` is called or when the listeners are notified about the state `DONE`. ------------- PR: https://git.openjdk.org/jdk/pull/11940
