What is start_wqthread? Does it affect the UIMainThread?

Question

I am using instrument (time profile) to analyze an app. In this figure, what does the start_wqthread mean?

Answer 1

The "wq" in start_wqthread stands for "work queue". It's the entry point for any thread started by GCD. It has no impact on the main thread, other than using hardware resources, same as any other code.