Re: [boost] [Review] Shmem, Serialization ad I/O streams (was: Shmem)

From: Reece Dunn (msclrhd_at_[hidden])
Date: 2006-02-12 09:08:27

Peter Dimov wrote:
>Reece Dunn wrote:
>
> > what happens if you have a class called shared_data that uses shmem,
> > and use it like this:
> >
> > shared_data data;
> >
> > int main()
> > {
> >   return 0;
> > }
> >
> > If this throws an exception, your application will crash and it could
> > be difficult to determine why.
>
>This is true for all classes. It doesn't matter whether shared_data uses
>shmem or not.

True, but we were discussing shmem and making it throw an exception if 
allocation fails. Throwing exceptions does make error handling easier in 
that the error reporting can be done in one place, but you have to be more 
careful about how you use classes that can throw. You could write my example 
as:

class shared_data
{
   boost::shared_ptr< shmem > shared;
public:
   shared_data()
   {
      try
      {
         ...
      }
      catch( shmem_exception & )
      {
         report_error_and_exit();
      }
      catch( std::bad_alloc & )
      {
         report_error_and_exit();
      }
   }
};

so you wouldn't need to have an error policy. This would work for other 
cases like this, not just using shmem.

- Reece