How to Work with Shared Memory in Rust

Rust does not provide a built-in shared memory API; you must use the memmap2 crate to map files into memory for inter-process communication. Add memmap2 to your Cargo.toml and use MmapOptions to create a memory-mapped file that multiple processes can read and write.

use memmap2::MmapMut;
use std::fs::File;
use std::io::Write;

fn main() {
    let file = File::create("shared_data.bin").unwrap();
    file.write_all(b"Hello from Rust").unwrap();
    let mut mmap = unsafe { MmapMut::map_mut(&file).unwrap() };
    mmap[0] = b'H';
}

Add this to Cargo.toml:

[dependencies]
memmap2 = "0.9"

Shared memory lets different programs talk to each other by reading and writing the same chunk of computer memory. In Rust, you do this by mapping a file onto your program's memory so changes are instantly visible to others. Think of it like a shared whiteboard where multiple people can write and see updates immediately without passing notes.