Zinc - Universal Shared Memory Library

Zinc gives processes in any language direct access to the same physical memory, across Rust, Python, Go, Node.js, Bun, Deno, C++, Java, C#, and more. No serialization, no copies, no kernel round-trips. Just mmap under the hood and a zero-copy view of the same bytes in every language.

Windows is not supported. Zinc is a Linux/macOS library built on POSIX shared memory (shm_open + mmap).

Think SharedArrayBuffer, but cross-language and cross-process.

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Why

SharedArrayBuffer lets Worker threads share memory within a single process. There's no equivalent across processes or languages. If you want two processes to share a large dataset (video frames, ML model outputs, game state, a shared cache), your options are: serialize it, copy it through a socket, deserialize it on the other side.

Zinc maps the same physical RAM pages into both processes via POSIX shared memory. Write a float in Python, read it in Go. No syscall, no copy, no serialization. The transfer time is zero because there is nothing to transfer. It is already there.

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Quick start

git clone https://github.com/ossl-dev/zinc
cd zinc
cargo build --release --manifest-path core/Cargo.toml

Rust

use zinc_core::SharedRegion;

let region = SharedRegion::create("/my-data", 4096)?;
unsafe { std::ptr::write(region.as_ptr() as *mut f32, 42.0) };
region.notify();

Python

from zinc import SharedRegion

r = SharedRegion.open("/my-data")
arr = r.as_numpy(dtype=np.float32)
print(arr[0])  # 42.0, same physical memory

Go

import "zinc"

r, _ := zinc.Open("/my-data")
data := r.Bytes()
val := *(*float32)(unsafe.Pointer(&data[0]))

TypeScript (Bun / Deno / Node)

import { SharedRegion } from "zinc-bun";

const r = SharedRegion.open("/my-data");
const view = new Float32Array(r.buffer());
console.log(view[0]); // 42.0

That's it. Every language sees the same bytes. Use Atomics on a typed array view for synchronization if you need it.

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How it works

┌──────────────────────────────────────┐
│  Python  │  Go  │  C++  │ Java │ C#  │  ← Adapters (thin FFI wrappers)
│  (cffi)  │(cgo) │(hpp)  │(JNA) │(P/Invoke)
├──────────────────────────────────────┤
│        include/zinc.h                │  ← C ABI (opaque void* handles)
│   zinc_create / zinc_open / ...      │
├──────────────────────────────────────┤
│        Rust core (cdylib)            │  ← Single source of truth
│   SharedRegion / Ring / Sync         │
├──────────────────────────────────────┤
│   POSIX shm_open + mmap + futex      │  ← Platform layer
│   (Linux, macOS)                     │
└──────────────────────────────────────┘

Every language adapter calls the same 8 C functions via its native FFI mechanism. The Rust core compiles to libzinc_core.{so,dylib,dll}. No logic is reimplemented in adapters.

The 8 C functions

Function	Purpose
zinc_create	Create owned region, returns opaque handle
zinc_open	Open existing region
zinc_ptr	Raw pointer to data area (after 64-byte header)
zinc_capacity	Usable bytes
zinc_close	Drop handle, unmap, maybe unlink
zinc_notify	Signal waiters (futex on Linux, spin elsewhere)
zinc_wait	Block until notified or timeout
zinc_version	Major/minor version for compatibility checks

Ownership model

• Creator owns the segment, others open it
• Ref-counted via atomic in the 64-byte header
• Only the creator may unlink (enforced at the type level)
• Automatic cleanup when all handles are dropped

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Performance

The shared buffer path has no "transfer" to benchmark: both processes access the same RAM. The cost is a single mmap setup call, then memory reads/writes at native speed (CPU cache → RAM bandwidth).

Target: notify/wait roundtrip < 5µs on Linux.

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Language adapters

Language	Mechanism	Status	Path	README
Rust	Direct crate	Core ready	core/	,
Python	cffi + numpy	Tests passing	adapters/python/	README
Go	cgo	Tests passing	adapters/go/	README
Node.js	napi-rs	Builds	adapters/node/	README
Bun	bun:ffi	Tests passing	adapters/bun/	README
Deno	Deno.dlopen	Tests passing	adapters/deno/	README
C++	Header-only RAII	CMake ready	adapters/cpp/	README
Java	JNA	Tests added	adapters/java/	README
C#	P/Invoke	Tests added	adapters/csharp/	README

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Building

# Build the Rust core (generates libzinc_core + include/zinc.h)
cargo build --release --manifest-path core/Cargo.toml

Output: core/target/release/libzinc_core.{so,dylib}

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Prerequisites

• Rust ≥ 1.82, rustup.rs
• Moon ≥ 2.0, moonrepo.dev (monorepo tool)
• Language runtimes as needed

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Development

See DEVELOPMENT_GUIDE.md for full build instructions, test suite, and architecture notes.

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License

MIT, see LICENSE.