Re: [Valgrind-users] Why doesn't freed C++ string memory when program exits?

[Julian S. <js...@ac...>]

Yes it is definitely one for the recently-expanded FAQ.  Some more 
info (or the complete FAQ entry :) would be helpful.  Specifically,
can you say how to disable the STL's memory pooling, since that will
be the next thing that people ask having read the below.

Thx

J

On Saturday 26 April 2003 10:42 am, Bastien Chevreux wrote:
> On Saturday 26 April 2003 02:03, Lee, HJ wrote:
> > If I use string type for example ---> string a("Hello, world"), the
> > memory allocated for string isn't freed when program exit.
> > valgrand reported it is not-freed block. Here is valgrind reports logs.
> > Why is it not freed when program exits? I am using RH6.2.
>
> The thread ""Reachable" memory, where's the bug (g++, STL, valgrind)?"
> might help you there. In short: the C++ STL and string function have their
> own memory pooling mechanisms to gain speed. The memory of these objects is
> not 'freed' per se when they are destructed, but returned to the internal
> memory pool and will be reused for other objects created. It's these pool
> fragments (which are not freed by the C++ library before exit) that
> valgrind chokes on.
>
> While you can minimise this behaviour with the STL by providing your own
> allocators (not recommended, slows down execution speed terribly on some
> systems), I am not aware of similar mechanisms for the string classes.
>
> Salut,
>       Bastien
>
> PS: This is _definitively_ something for the FAQ.