Re: [boost] boost::thread, win32 implementation woes

From: William Kempf (williamkempf_at_[hidden])
Date: 2002-04-10 09:17:31

>Boosters,
>
>there are some pitfalls using boost::thread on the win32 plattform
>if DLLs are involved. As I could find nothing in the documentation
>mentioning this I would like to ask if a strong warning could be
>added, that creating threads in DllMain() or in a global object
>living in a DLL will deadlock. This is especially suprising as
>using _beginthread() or CreateThread() does work in such places.
>
>The problem is, when boost::thread creates a thread it explicitly
>waits for the start up of the newly created thread. But if the
>creator of the thread itself is in DllMain() or something alike
>the newly created thread won't start until the creator leaves
>DllMain().
>
>The documentation for CreateThread() in the plattform SDK says
>the following on this subjekt: "During process startup and DLL
>initialization routines, new threads can be created, but they
>do not begin execution until DLL initialization is done for the
>process."

Thanks for bringing this to my attention.  I was aware of the issues 
involved here, but didn't make the mental connection that the implementation 
would cause any issues.  Since I never create a thread in DllMain() or in a 
globaly constructed object the problem never presented itself to me.  I'll 
look into whether there's a way to eliminate this undesirable behavior, or 
if not, add documentation to this effect.

Bill Kempf
williamkempf_at_[hidden]

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