Re: [Boost-users] [date time] Something leaks in operator<<

From: Jeff Garland (jeff_at_[hidden])
Date: 2007-05-28 09:45:42

Seweryn Habdank-Wojewódzki wrote:
> Hi
> 
> I do not know if date time leaks or not, 

Don't think so.

> but I want to clarify that before I will send information to libstdc++ bugzilla.

Not sure there's really a leak...

>     date b1 (2007,2,3);
>     date b2 (2007,2,7);
> 
>     cout << b1 << '\n'; // line 12

This statement will install the default date-time output facet.  Facet's have 
a reference counting mechanism which should provide for release upon 
destruction of the stream.  So there wouldn't be any removal till the end of 
the program.

> [2007-Feb-03/2007-Feb-06]
> ==2382== 
> ==2382== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 7 from 1)
> ==2382== malloc/free: in use at exit: 856 bytes in 26 blocks.
> ==2382== malloc/free: 58 allocs, 32 frees, 2,772 bytes allocated.
> ==2382== For counts of detected errors, rerun with: -v
> ==2382== searching for pointers to 26 not-freed blocks.
> ==2382== checked 107,996 bytes.
> ==2382== 
> ==2382== 20 bytes in 1 blocks are still reachable in loss record 1 of 7
> ==2382==    at 0x4021FB4: operator new(unsigned) 
> (in /usr/lib/valgrind/x86-linux/vgpreload_memcheck.so)
> ==2382==    by 0x8049CDD: 
> std::locale::locale<boost::date_time::date_facet<boost::gregorian::date, 
> char, std::ostreambuf_iterator<char, std::char_traits<char> > > >(std::locale 
> const&, boost::date_time::date_facet<boost::gregorian::date, char, 
> std::ostreambuf_iterator<char, std::char_traits<char> > >*) 
> (locale_classes.h:568)

This is the aforementioned facet.

 >...snip....
> ==2382== LEAK SUMMARY:
> ==2382==    definitely lost: 0 bytes in 0 blocks.
> ==2382==      possibly lost: 340 bytes in 19 blocks.
> ==2382==    still reachable: 516 bytes in 7 blocks.
> ==2382==         suppressed: 0 bytes in 0 blocks.
> 

'possibly lost' seems less than conclusive that there's actually a leak.

Jeff