Boost shared memory. How many processes are currently using the shared memory?

I am sharing some memory between processes, using the boost library;

boost::interprocess::managed_shared_memory managed_shm(boost::interprocess::open_or_create, "shm", 1024);

is there a way to find out h开发者_开发问答ow many processes are currently accessing this memory?

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If you can get the underlying SHM ID, you can use shmctl function to get the number of processes having the segment attached.