Shared Memory Lock

A multiprocessing lock implemented using shared memory and atomics.

Installation

uv pip install -e .

Usage

from shared_memory_lock import SharedMemoryLock

# Create a lock (first process)
lock = SharedMemoryLock(name="my_lock", create=True, run_id="app1")

# Connect to the same lock (other processes)
lock = SharedMemoryLock(name="my_lock", create=False, run_id="app1")

# Use as context manager
with lock:
    # Critical section - only one process can be here
    print("Doing important work...")

# Or manual acquire/release
if lock.acquire(blocking=False):
    try:
        # Got the lock
        print("Acquired lock!")
    finally:
        lock.release()
else:
    print("Could not acquire lock")

# Clean up when done
lock.close()
lock.unlink()  # Only call from one process

Features

• Cross-process synchronization: Works across multiple processes
• Atomic operations: Uses real atomic compare-and-swap for mutual exclusion
• Picklable: Can be passed to multiprocessing.Process
• Context manager: Supports with statements
• Non-blocking: Optional non-blocking acquire with timeout

Development

# Install dependencies
uv sync

# Run tests
uv run --python 3.13.7 pytest 

# Run tests with coverage
uv run --python 3.13.7 pytest --cov=shared_memory_lock

License

MIT