> In terms of providing "consistent behavior across platforms that can be
> reasonably supported", the behavior suggested above could not
> reasonably be supported in Windows.

I understand that persistence of a shared memory segment after all the processes using it exit, can be very difficult on Windows.

But, after testing shared_memory on Windows, the behavior on Windows and Unix is not consistent at the moment.

For instance:
Let's say a three processes P1, P2 and P3 are trying to communicate using shared memory.
 --> P1 creates the shared memory block, and waits for P2 and P3 to access it.
 --> P2 starts and attaches this shared memory segment, writes some data to it and exits.
 --> Now in case of Unix, shm_unlink is called as soon as P2 exits.
 --> Now, P3 starts and tries to attach the shared memory segment.
 --> P3 will not be able to attach the shared memory segment in Unix, because shm_unlink has been called on that segment.
 --> Whereas, P3 will be able to attach to the shared memory segment in Windows

One possible solution can be, to register the shared the shared_memory only when it's created and not when it's attached.

I think that might make Unix's implementation more consistent with windows.

Any thoughts on the same will be very helpful.