Various interprocess communication mechanisms are well supported by standard python libraries such as
Multiprocessing. However, these means are designed to implement IPC mechanisms between related processes, that is, those that are generated from a common ancestor and thus inherit IPC objects. However, it’s often required to use IPC facilities in unrelated processes that start independently. In this case, named IPC objects (POSIX or SysV) should be used, which allow unrelated processes to obtain an IPC object by a unique name. This interaction is not supported by standard Python tools.
Python 3.8 introduced the multiprocessing.shared_memory library, which is the first step to implementing IPC tools for communication of unrelated processes. This article was just conceived as a demonstration case of this library usage. However, everything went wrong. As of November 29, 2019, the implementation of shared memory in this library is incorrect – the shared memory object is deleted even if the process just wants to stop using the object without the intention of deleting it. Despite the presence of two calls
unlink (), regardless of their call or non-call, the object is deleted when any of the processes using the object terminates.