Not really no, not that I can think of, nothing simple at least. That's one issue with Cocoa's drawing code being main-thread only and with things like NSTableView being totally tightly bound to their datasource and delegate and liable to call them at any time (drawing, scrolling, just feeling like it), and calling more than one method in a sequence (not synchronized across the entire method call), using them cross-thread is tricky indeed.
I will be interested to see if there are some simple patterns people have found to work, I haven't. In the one case I did this I batched my updates into sets of adds, deletes and changes and then blocked (or at that time performSelector'ed) them onto the main thread where they were applied to the data model there. I can certainly see cases in which that's hard to do and you want to adjust the data model on your thread and then just say redraw. On Apr 27, 2012, at 3:42 PM, Jean Suisse wrote: > So if I understand you correctly alteration of the dataSource should always > be performed on the main thread. > [implied: because requests for redraw or similar that do not come from my > code will always run on the main thread. Is that right ?]. > > Done. Not easy, but done. (Things were a little more complicated than just > dispatching a block). > > Now, for the sake of knowledge, I would like to consider the case where I > can't always alter the datasource on the main thread. What then ? > I recall assembly instructions (STI, CLI) to prevent IRQ from occurring > inside a few line of code. > Is there some way to prevent thread switching for a short time ? Do you know > an other way to deal with the present issue (alteration of the dataSource of > an NSTableView not performed on the main thread) ? > > Jean > > On 26 avr. 2012, at 21:47, Corbin Dunn wrote: > >> >> On Apr 26, 2012, at 3:23 AM, Jean Suisse <[email protected]> wrote: >> >>> Dear Peter, >>> >>> Thank you for your reply. Here is the requested code (see below). >>> After more investigations, I would like to take back a previous statement, >>> that the tableview was perfectly aware that the number of rows in the DS >>> was changed. This is due to my inexperience in stepping through the code >>> across multiple threads. >>> >>> Here are the facts : >>> >>> - Only the controller removes rows from the datasource. Either in response >>> to user actions (canceling tasks) or as a result of a Task completed >>> notification from a running task. >>> - Each change in the dataSource is immediately followed by a reloadData >>> message sent to the TableView. >>> - Sometimes, randomly, the TableView requests a row index that is out of >>> bounds by one index (e.g. row #5 when the dataSource contains only 5 >>> elements). >>> >>> I am thinking that a redraw occurs in-between the removal of one element of >>> the table and the reloadData message. >>> For now, I did a quick fix for this issue by adding a category with >>> "safeObjectAtIndex"…. But one way to be certain would be to ensure that the >>> two messages (removal + reloadData) are sent without any thread/process >>> switching occurring… >>> >>> The code for numberOfRowsInTableView : (experimentList is an instance of >>> NSMutableAray) >>> >>> - (NSInteger)numberOfRowsInTableView:(NSTableView*)tableView >>> { >>> return self.experimentList ? [self.experimentList count] : 0; >>> } >> >> This is fine as long as your experimentList is only ever modified on the >> main thread. >> >> It sounds like that isn't the case, which is why you have random problems. >> >> corbin >> >> >>> >>> Jean >>> >>> >>> On 26 avr. 2012, at 11:45, Peter Hudson wrote: >>> >>>> >>>> Can you post your code for numberOfRowsInTableView: >>>> >>>> Peter >>> >>> >>> _______________________________________________ >>> >>> Cocoa-dev mailing list ([email protected]) >>> >>> Please do not post admin requests or moderator comments to the list. >>> Contact the moderators at cocoa-dev-admins(at)lists.apple.com >>> >>> Help/Unsubscribe/Update your Subscription: >>> https://lists.apple.com/mailman/options/cocoa-dev/corbind%40apple.com >>> >>> This email sent to [email protected] >> > > > _______________________________________________ > > Cocoa-dev mailing list ([email protected]) > > Please do not post admin requests or moderator comments to the list. > Contact the moderators at cocoa-dev-admins(at)lists.apple.com > > Help/Unsubscribe/Update your Subscription: > https://lists.apple.com/mailman/options/cocoa-dev/rols%40rols.org > > This email sent to [email protected] _______________________________________________ Cocoa-dev mailing list ([email protected]) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [email protected]
