Improve overlapped deallocation strategy and docs

[PerfectLaugh]

This should solve the error return memory leak.

[carllerche]

Thanks for following up. Is there a way to add a test that covers the leak?

[PerfectLaugh]

I don't know how to write a test for that.
But you just have to deallocate the overlapped pointer if you have error on Afd driver poll. Even when the operation is cancelled, the overlapped will be used by IOCP with cancelled status.

[PerfectLaugh]

and I have confirmed that double free is occurred when cancel without forgetting overlapped.

[Thomasdezeeuw]

@carllerche is this good to merge?

[carllerche]

👍 Thanks