Re: [Boost-users] serialization gives memory leaks due to throwingconstructors

From: gast128 (gast128_at_[hidden])
Date: 2007-03-02 05:00:25

Robert Ramey <ramey <at> rrsd.com> writes:

> Note: the function of 'delete_created_pointers'  is to delete any
> pointer created during the process of loading.  Construction
> of an archive creates no such pointers.  So not calling
> 'delete_created_pointers' in this case will have no effect and
> does not need to be called.

Ok 3 things:
1) I think a throwing ctor should not create memory leaks. I believe Sutter 
has comments about this in his book
2) The loaded XML file can be altered by users. Therfore the load can fail and 
I want it to be guarded. But now I have to add a double guard:

bool Load(const std::string& cr)
{   
    std::fstream fstr(cr);

    try
    {
        boost::archive::xml_iarchive ia(fstr);
  
        try
        {
           ia >> ...;
           return true;
        }
        catch (boost::archive::archive_exception& re)
        {
            ia.delete_created_pointers();
        }
    }
    catch (boost::archive::archive_exception& re)
    {
    }
    
    return false;
}
3) I am aware of this 'exception versus error returning' discussions. A good 
article is written by Sutter in cuj august 2004 'When and How to Use 
Exceptions'. But I get the impression that this is a discussion between 
academic correct code versus common practice. In our company we have the 
policy that subsystems should not let escape exceptions. An unimportant class 
should not terminate the application because an exception is not caught. The 
GUI layer should not terminate the application because it cannot display all 
its elements. I would suggest for those c++ gurus to take software 
architecture in consideration when requiring this exception stuff for all 
classes. If you follow their rules all the time it takes twice the effort to 
code applications. And it will probably terminate a lot more due to uncaught 
exceptions from the 80% classes which are mildly important.

Wkr,
me