El 09/07/2013 12:17, Riskybiz escribió:

“It's not an easy task. You should catch the exception and then notify all connected processes that should disconnected from the segment (as only offline growing is supported). After that a process can call "grow"

to try extend the segment. Then, all processes can attach to the newly grown segment.

Think of that as a complex binary file that must be extended and internal structures changed. All users should close the file, the file should be changed by a process and then all users can start using the file again.”

OK Ion, thank you for that, I see……..

1.Can I ask what mechanism you would suggest for notifying the other processes to disconnect before the grow() operation?

A condition variable or semaphore could do the work, but all processes should check it periodically.

2.Considering how to deal with the issue of dynamically growing a shared memory vector where there is one producer process and several consumers; I hit upon the notion of having the producer process use a std::vector to conventionally store data and then using a boost shared memory segment to store a pointer to the std::vector. Consumer processes would access the boost shared memory to retrieve the pointer value thus enabling access to the std::vector data store in the producer process. This, I hoped, might remove the complexities associated with dynamically growing a shared memory segment? The big question is: _would it work_? Would this be a valid means of interprocess communication? Or fraught with complexities?

That wouldn't work. The memory where std::vector is stored is not accesible to other processes. Only memory explicitly shared (via managed_shared_memory, or lower level shared_memory_object) is accesible to other processes. I'm afraid that what you are trying to achieve is very complex. I have never tried to do it so I'm afraid you won't find many people to guide you in this issue. Good luck. Ion