Hi, I am trying to use condition variables to signify updated data in a managed_shared_memory segment. I have one "writer" and multiple "readers" of the shared state, so I am using a readers-writer lock as follows: using SharedMutex = bi::named_sharable_mutex; using ReadLock = bi::sharable_lock<SharedMutex>; using WriteLock = bi::scoped_lock<SharedMutex>; using NewEntryCondition = bi::named_condition_any; // With a "writer" block as follows: { WriteLock w_lock( sh_mut_ ); // Update the shared memory object sh_cond_.notify_all(); } // And a "reader" block as follows (many processes call the following simultaneously): { ReadLock r_lock( sh_mut_ ); sh_cond_.wait( r_lock, []() { std::cout << "checking predicate..." << std::endl; // predicate logic goes here... }); // Access object in shared memory here } Unfortunately, although the code compiles, the reader processes are never awakened from wait() and block forever. According to the following thread from 2011: http://lists.boost.org/boost-users/2011/02/66053.php "POSIX does not support condition variables with read-write locks (although I think Windows Vista does) so Interprocess does not offer any support for this." At the time, it appears named_condition_any didn't yet exist. Has the status of this changed in the last 5 years? Is there a suggested way of implementing readers-writer locks with condition variables using boost::interprocess? Thanks! -- Chris Evans Systems Engineer Azure Summit Technology, Inc. 3050 Chain Bridge Road, Suite 600 Fairfax, VA 22030