Testing Concurrency With Virtual Box

[Marc W]

I am testing a program. A reported error has something to do with information being send and received from 2 instances of the same program. In my test situation one is running on my PC, the other one is running in a virtual box. I cannot reproduce this error, but there is one thing I have not, and cannot, try: Clicking on a button in both instances at exactly the same time.

Is there any way I can simulate this? I presently thinking of just programming a sleep in one version of that program, and use the sleep to go to the other instance. (And in that other instance, I have turned off that sleep before triggering the button code, of course.)

But do you have any other ideas?

To make my information complete:
In both cases the operating System is Windows 7.
The application being tested actually a WinForms application. I have the source code. (Hence I can program that sleep in that button.)
I am using Network bridge adapter to get my machine and the box in the same network.
I have installed serial port COM1, the application needed a COM port to run.

[noteirak]

but there is one thing I have not, and cannot, try: Clicking on a button in both instances at exactly the same time.

Why can't you reproduce it?

[Marc W]

I do not know why I cannot reproduce it. If I knew why I could not reproduce it, then I could either confirm it was not an error anymore, or get it reproduced. It might be that it has something to do with not being able to get the mouse click at my host and the virtual box at the same time. Hence I am asking, is there a clever way to get for example two mouses at the same time. One on my host, on in the virtual box. And then click at the same time? Or something else? I did it with a sleep in the button like I described, and this way the error was not reproduced either.

I actually closed the bug as not reproducible and gave it back. But if someone has a suggestion, other then, make a real life set-up, I am happy to take a look at that.