Avoid crash updateChannelListTableCell

[wutschel]

From a comment by @kambala-decapitator it is per documentation not allowed to call reloadData between beginUpdates/endUpdate. In the App's code this might happen when the worker thread which updates the information for the visible channels is concurring with the updates trigger from the main thread. Choices to fix this is either using dispatch_sync to serialize any such event, or simply using reloadData. The latter will not only update the visible entries of the channel list, but all of them.

The reloadData solution (https://github.com/xbmc/Official-Kodi-Remote-iOS/compare/master...wutschel:fix_channelupdate):

• Very long channel lists (if a user should e.g. have all satellite stations in the list) will be processed, even though not visible.
• Is reloadData thread-safe?

The dispatch_sync solution would require each reloadData call inside DetailViewController to be encapsulated with dispatch_sync. In this case I would introduce helper methods for this.

[kambala-decapitator]

reloadData must be called only from the main thread

[wutschel]

I need to correct myself. The function which possibly concurs is called via a timer. Is a timer spawning a worker thread well?

[kambala-decapitator]

Timer callback is called on the thread which you schedule the timer on

[wutschel]

Thanks, then this is main thread.

[wutschel]

Do I still need to use dispatch_sync to avoid that beginUpdates / endUpdates is interrupted by reloadData when all calls come from the main thread?

[kambala-decapitator]

Do I still need to use dispatch_sync to avoid that beginUpdates / endUpdates is interrupted by reloadData when all calls come from the main thread?

sorry, missed your question. If you attempt to execute

dispatch_sync(dispatch_get_main_queue(), ^{ ... });

on main thread, you'll get into deadlock.