[boost] Re: Windows MSVC thread exit handler for staticly linked Boost.Threadn

From: Michael Glassford (glassfordm_at_[hidden])
Date: 2004-08-03 09:13:20

Aaron W. LaFramboise wrote:

[snip previous conversation]

>>The DllMain() or tls_callback() functions call on_thread_enter() for 
>>both the DLL_PROCESS_ATTACH and the DLL_THREAD_ATTACH messages, and they 
>>call on_thread_exit for both the DLL_PROCESS_DETACH and 
>>DLL_THREAD_DETACH messages.
>>
>>This scheme seems a little cleaner and so far seems to be working OK. 
>>Any thoughts about this?
> 
> 
> Yes I think reference counting seems like a good idea here.
> 
> The only concern I have--I don't know how important this is--is that
> when a thread is killed with TerminateThread, I think neither TLS
> callbacks nor DllMain()s will be called.  This would cause the TLS count
> to never reach zero, and for TlsFree to never be called.

Good point. Two comments: 1) If you're calling TerminateThread, you're 
probably already leaking; maybe one more leak won't matter. And...

> These threads might not even be associated with the Boost TSS at all.
> For example, another third party library in some DLL might be using
> TerminateThread, and the application programmer may not even know about
> this, so it may be suprising to him when the reference count never
> reaches zero for apparently no good reason.

2) I"m only reference counting threads on which Boost.Threads tss is 
actually used, so this shouldn't happen.

Mike