From: Grimm, Matthias (matthias.grimm_at_[hidden])
Date: 2021-03-12 14:41:48
Hi,
I have a question regarding the interprocess library and the use of shared memories.
When creating a boost::interprocess::managed_shared_memory it seems to be necessary to take some additional space into account. In my case the following approach works well:
managed_shm = new ip::managed_shared_memory(ip::create_only, "shm_id",
(vec_elems + 110) * (number_of_samples + 1));
Following this it seems to be necessary to always have one additional element. If I remove the additional element
(vec_elems + 110) * (number_of_samples)
an exception is thrown: boost::interprocess::bad_alloc. This is also the case if I change to
(vec_elems) * (number_of_samples + 1)
Does anybody know why it is necessary to have this additional space allocated? What is the exact minimum size to avoid the exception? The additional memory may become a problem if the size of the vector elements is large.
Attached you'll find some example code. Any help on this topic would be appreciated.