Re: [Boost-users] Boost.Thread memory leak reported

From: Daniel Krügler (dsp_at_[hidden])
Date: 2005-08-30 02:34:24

Howard Hinnant wrote:
> On Aug 29, 2005, at 3:47 PM, Peter Dimov wrote:
> 
> 
>>I haven't studied the threadmon code in detail, though. It might be 
>>possible
>>to destroy the threadmon mutex safely at some point during shutdown.
> 
> 
> I haven't studied threadmon either.  But from the sounds of it, you may 
> want to consider a "phoenix" singleton, nicely documented in Andrei 
> Alexandrescu's MC++D.  One hitch to get a working phoenix singleton is 
> to have a working atexit function (and I mean really working 
> correctly).  There was a lwg dr report on it:
> 
> http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#3
> 
> which has now received TC status, meaning it is a normative part of the 
> C++03 standard.  I have no information on how well the various 
> platforms conform to the standard in this regard (it can be tested for 
> though).
> 
> The idea is fairly simple.  The singleton factory keeps state that 
> tells it whether the singleton is constructed or not.  When the 
> singleton gets constructed, it registers a "destructor" with atexit.  
> If after the atexit runs the destructor, the singleton is needed again, 
> then it recreates itself, and re-registers with atexit.  A correctly 
> working atexit will properly run this newly registered function as it 
> continues to process the atexit chain.

Interestingly a more recent report from Plauger - but still open - 
recommends a contradictory advice (at least as far as I understand it), see

http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-active.html#462

Greetings from Bremen,

Daniel Krügler