issue with regsvr32 utility

[henry1999sg]

in my last posting, I reported the issue with register a non-COM dll. now I got more details about the issue now.

we I have 2 dll. A.dll uses B.dll. both are normal dll with static linking being useb y some applications. In our customer, a policy is to register all dlls in a directory at window login. so we can't skip these dlls.

Now the regsvr32 will call the following functions on the dll

>LoadLibraryEx
>GetProcAddress
>FreeLibrary

When in LoadLibraryEx, the following steps are carried out

 1. B.dll is loaded. 
 2. call DllMain of A.dll with DLL_PROCESS_ATTACH
 3. call DllMain of A.dll with DLL_THREAD_ATTACH

Then call to FreeLibrary
4. call DllMain of A.dll with DLL_PROCESS_DETACH.

But since there is a DLL_THREAD_ATTACH and not corresponding DETACH, the A.dll is blocked and FreeLibrary never exits. So does regsvr32.

is there any guru having a idea why this happen ? I am puzzled with why there is a DLL_THREAD_ATTACH process..

thanks in advance.. cheers !

[webJose]

AFAIK, there is always a DLL_THREAD_ATTACH call: The first load has to have been done in a thread, right?

Nope. Scratch the above. Apparently I am not correct: http://msdn.microsoft.com/en-us/library/ms682583(VS.85).aspx . You might want to read the whole thing as I did not.

Summary in the context of what I said: If a thread calling LoadLibrary() produces the call with DLL_PROCESS_ATTACH, but nothing else. DLL_THREAD_ATTACH is only called by additional threads.

The document also states that DLL_THREAD_DETACH is only called by thread that cleanly exit. I therefore conclude that a DLL should not expect the thread count to go back to zero (meaning there's a detach for every attach) before getting DLL_PROCESS_DETACH.

[henry1999sg]

thanks webJose

the issue is a global variable which create a thread. When the DllMain is called, this variable is created which spawns a thread. However this thread can't be terminated in DLL_PROCESS_DETACH.

so I have to change this gloable variable to a static local. then it is solved.

Cheers !