---
id: sysv-ipc
version: "1.2.0"
license: BSD-3-Clause
license_treatment: permissive
maintenance: aging
---

# sysv-ipc — SysV IPC primitives (semaphores, shared memory and message queues) for Python

License: permissive · Maintenance: aging · Downloads: 207.6K/mo

## What it is and what it does

sysv_ipc is a C-based Python module that wraps the native System V IPC API, letting you create and manage semaphores, shared memory segments, and message queues on Unix-like systems. It's a thin binding to the underlying OS primitives rather than a high-level abstraction, so you interact with them much as you would in C—acquiring semaphores, attaching to shared memory, sending and receiving messages. The module is stable and production-ready, with no known vulnerabilities and a long release history dating back to 2014.

You'd use this when you need low-level inter-process communication on Unix systems—typically for coordinating multiple processes on the same machine, sharing data efficiently without serialization overhead, or implementing classic Unix patterns. It's not a replacement for higher-level IPC libraries; it's for cases where you specifically need System V IPC semantics or are integrating with existing C code that uses them.

Use it for:

- Coordinate multiple Python processes using System V semaphores for mutual exclusion or signaling.
- Share large data structures between processes via System V shared memory without serialization overhead.
- Implement message-passing patterns between processes using System V message queues.
- Integrate Python code with existing C applications that rely on System V IPC primitives.
- Build process pools or worker systems that need efficient, OS-level synchronization on Unix.

## Worth the install?

AI-flagged interpretation of the facts above — verify before relying.

Provides Python access to System V IPC primitives—semaphores, shared memory, and message queues—on Unix-like systems via a C extension module.

Yes, if you need System V IPC on Unix systems. The package is stable, permissively licensed, has no known vulnerabilities, and offers prebuilt wheels for common platforms. Install friction is moderate due to the C extension, but wheels are widely available. Not suitable for Windows without WSL/Cygwin, and only necessary if you specifically require System V IPC semantics rather than higher-level alternatives.

## Install

pip install sysv-ipc
uv add sysv-ipc
poetry add sysv-ipc

## Installing sysv-ipc

Before you install: Medium install friction due to compiled C extension; prebuilt wheels available for Python 3.10–3.13 on macOS, Linux (x86_64 and aarch64), and musl-based systems. Last release 217 days ago; repo is active and not archived, though maintenance status is aging.

License in practice: Released under BSD-3-Clause (permissive), allowing commercial and private use with minimal restrictions; include a copy of the license in distributions.

Quickstart:

pip install sysv-ipc

import sysv_ipc

# Create or access a semaphore
sem = sysv_ipc.Semaphore(flags=sysv_ipc.IPC_CREAT)
sem.acquire()
sem.release()

Requires a Unix-like OS with System V IPC support (Linux, macOS, BSD, Solaris); not available on Windows without WSL or Cygwin. No minimum Python version specified in metadata.

Verify before relying:

- Whether Windows + WSL or Cygwin support is reliable or tested in practice.
- Current status of Python 2.x compatibility mentioned in the description.
- Whether the six-year gap since the last reported bug reflects maturity or lack of active use.

## Package facts

- License: BSD-3-Clause (permissive)
- Python support: unspecified
- Install friction: medium
- Maintenance: aging
- Downloads: 207.6K/month (top 15,000 on PyPI)
- Known vulnerabilities: none known

## Tags

system v ipc python, semaphores shared memory message queues, unix ipc primitives, interprocess communication python, sysv semaphore python, shared memory access python, message queue unix, ipc, unix-systems, c-extension

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