Re: [Boost-users] boost::thread join() and DLL unloading

Subject: Re: [Boost-users] boost::thread join() and DLL unloading
From: John M. Dlugosz (mpbecey7gu_at_[hidden])
Date: 2011-09-14 20:47:21

On 9/14/2011 4:48 PM, Christopher Pisz wrote:
> I've googled for a few hours and seen people mention something to the effect
> of "you cannot call join from DllMain" and "while DLL is unloading", but no
> explanation or alternative.
>
> How would I go about fixing this problem?
> I don't think I can guarentee noone will ever make a global instance of my
> class....

As I recall, the DLLMain's as well as process startup code in the main EXE is called with 
a process mutex, so threads cannot be started until the normal main is called.  Likewise 
at shut-down, but I don't know what happens to other threads.  I suspect they are halted 
before the unloading process begins.  Once your main() returns, at some point threads are 
halted so ensure that threading is done before that!

I assume you mean the DLL is unloading because the process is terminating.  I don't know 
if that's still the case for dynamic LoadLibrary.