How to test at runtime if a block is currently executed on the main queue?

Question

I am using an API where it is not entirely clear if the block is always executed on the main queue. If it is not, then I need to call the main queue synchronously.

How can I check if the block is already executing on the main queue? dispatch_get_current_queue() is deprecated. Must I use dispatch_get_specific() to get an comparable identifier?

Answer 1

The unique thing about the main queue is that it is always matched exactly to the main thread. So you can use [NSThread isMainThread] .