When ThreadPool.QueueUserWorkItem returns false

Question

The MSDN states that the method returns

true if the method is successfully queued; NotSupportedException is thrown if the work item is not queued.

For testing purposes how to get the method to return false? Or it is just a "suboptimal" class design?

Answer 1

In looking at the source code in Reflector, it seems the only part of the code that could return "false" is a call to the following:

[MethodImpl(MethodImplOptions.InternalCall)]
private static extern bool AdjustThreadsInPool(uint QueueLength);

Answer 2

This is probably a case of "reserved for future use". You may want to treat it as failure, but it'll be hard to test.

I pretty much treat this method as a void/Sub.

Answer 3

It is imaginable that the entire API (thread-pools) becomes obsolete, when the Task Parallel Library (TPL) arrives.