Question

We just spent 300 man-hours fixing a buggy application in the field. It all came down to calling Application.DoEvents (re-entrancy problem).

This was not caught in design reviews, code reviews. The code was inserted two years ago with the first version; the application was always ‘flaky’ but recent changes exposed the re-entrancy problems to a greater degree.

This incident is the second time in our organization that Application.DoEvents caused failures and multi-man hours of debugging. It was discovered in this case by simply noticing the call, buried way down in a complex event handler for an asynchronous task.

What do you suggest to prevent this issue from happening again:

• Add checkin gates to source control?
• Developer training?
• Code Analysis rules (why is this not already a built-in rule?)

How to I enforce a coding practice?

Answer 1

Every time the application is built centrally, run this on every assembly:

ildasm MyAssembly.exe /TEXT 

Then search the output for:

System.Windows.Forms.Application::DoEvents 

If it’s found, mark the build as failed, as if it was a compile error.