shmbuf

Cross-platform shared memory for Node.js. Returns a SharedArrayBuffer backed by OS shared memory (shm_open+mmap on Linux/macOS, CreateFileMapping+MapViewOfFile on Windows). Multiple Node.js processes opening the same named segment share the same physical memory pages — writes are instantly visible across processes with no IPC, no fsync, no serialization.

Use Atomics directly for lock-free cross-process coordination.

Install

npm install shmbuf

Usage

const { open, close, unlink } = require('shmbuf');

const buf = open('/myapp-lock', 64);
const view = new Int32Array(buf);

Atomics.add(view, 0, 1);
Atomics.compareExchange(view, 1, 0, 1);
const gen = Atomics.load(view, 2);

close('/myapp-lock');
unlink('/myapp-lock');

API

open(name, size) → SharedArrayBuffer

Creates or opens a named segment of size bytes. On POSIX, name must start with '/'.

close(name)

Unmaps this process's view. The segment persists until unlink() is called.

unlink(name)

Destroys the named segment. No-op on Windows.

Fallback

If the native build fails at install time, falls back to in-process SharedArrayBuffer. Cross-process sharing will not work. A warning is emitted.

License

MIT