Re: [Boost-users] [interprocess] shared memory containing a vector of unions of strings/integers/doubles

From: Ion Gaztañaga (igaztanaga_at_[hidden])
Date: 2008-04-29 11:26:51

Jason Sachs wrote:
> OK, let me ask a simpler question:
> 
> If I have a structure S which contains a shared memory allocator, can 
> that structure be safely stored in shared memory? (e.g. if I construct S 
> in one process, use the memory allocator to construct some other pointer 
> p in shared memory, then locate S in another process and use the memory 
> allocator to destroy pointer p, will that work properly, or have I 
> invited Disaster?)

If the structure stores the allocator and all other pointers to any type 
(say X) inside the structure are of the same type as 
boost::pointer_to_other<allocator::pointer, X>::type that structure is 
mappable in different addresses in different processes.

E.g.: Shared memory containers are classes that store a shared memory 
allocator to allocate dynamically memory from the shared memory segment. 
Any internal pointers of those containers (for example an internal 
pointer pointing to the memory allocated with the shared memory 
allocator) is the same type of smart pointer (offset_ptr<T>) as 
allocator::pointer.

Regards,

Ion