Shared Memory via memfd_create and Unix Domain Sockets

This project demonstrates creating shared memory in a server/client process setup. Unlike the traditional parent/child process relationship, this approach allows an arbitrary client process to share memory with a server process.

How It Works

1. Client side

   • Create a file descriptor (FD) using memfd_create.
   • Map that FD into the client’s memory space using mmap.
   • Send the FD to the server process over a Unix domain socket.

2. Server side

   • Receive the FD over the socket.
   • Perform its own mmap to map the shared memory region into its address space.
   • Both processes can now access the same shared memory.

Benefits

• Works across unrelated processes (not limited to forked parent/child).
• Uses Linux-native primitives (memfd_create, mmap, Unix domain sockets).
• Enables flexible IPC for high-performance applications.

TODO / Next Steps

• Define a protocol: prevent arbitrary or unauthorized clients from connecting.
• Synchronization: when multiple processes read/write to shared memory, proper synchronization is required. A common approach is using futex for lightweight locking.