Re: [Boost-users] [asio] Boost-1.65.0 TlsSlot leak on win32

Subject: Re: [Boost-users] [asio] Boost-1.65.0 TlsSlot leak on win32
From: Gavin Lambert (gavinl_at_[hidden])
Date: 2018-03-20 04:33:33

On 20/03/2018 05:08, Klebsch, Mario wrote:
> I am using boost version 1.65.0 in a 32 bit DLL. I use VS2005
> 
> When using ApplicationVerifier, I got application verifier stops due to 
> leaked TLS slots.
> 
> The TLS slots are allocated in win_tss_ptr_create(). Each slot is 
> wrapped into RAII class win_tss_ptr. The constructor allocates the TLS 
> slot and the destructor de-allocates it.
> 
> I put printf-Statements in both methods and I see, that the constructor 
> is called twice, while the destructor is not called at all. If I put a 
> breakpoint into the destructor, it never triggers.

How is your process exiting?  Global destructors will only be called if 
execution leaves main/WinMain normally (without calling terminate, 
abort, _exit, TerminateProcess, throwing an exception, etc) -- and 
they'll (silently) stop being called if any destructor does throw an 
exception.

Also, unless you are dynamically unloading and reloading the DLL (and 
dynamically unloading the DLL should trigger the destructors), a *small* 
TLS slot leak is not that important as they are destroyed when your 
process exits anyway -- despite annoying AppVerifier.  The main thing 
the checks are there for are if you are leaking TLS slots each time you 
call a particular method or something.