Maximum queued elements in ThreadPool.QueueUserWorkItem

Question

I set the max thread to 10. Then I added 22000 task using ThreadPool.QueueUserWorkItem. It is very likely that not all the 22000 task was completed after running the program

Answer 1

This is an implementation dependent question and the implementation of this function has changed a bit over time. But in .Net 4.0, you're essentially limited by the amount of memory in the system as the tasks are stored in an in memory queue. You can see this by digging through the implementation in reflector.