{"library":"locket","title":"Locket","description":"Locket is a Python library (version 1.0.0, last released April 2022) that provides file-based locks for inter-process communication on both Linux and Windows. It offers a simple API for creating non-reentrant locks that behave similarly to `threading.Lock` instances, uniquely identified by the file path being locked. The library ensures that only one process can acquire a lock at a time for a given path, preventing conflicts when multiple processes access shared resources.","language":"python","status":"maintenance","last_verified":"Tue May 12","install":{"commands":["pip install locket"],"cli":null},"imports":["import locket","from locket import LockError"],"auth":{"required":false,"env_vars":[]},"quickstart":{"code":"import locket\nimport os\nimport time\n\n# Define a lock file path, using an environment variable for flexibility\nlock_file_path = os.environ.get('LOCKET_EXAMPLE_PATH', './my_app.lock')\n\nprint(f\"Attempting to acquire lock on {lock_file_path}...\")\ntry:\n    # Acquire the lock using a context manager, with a 5-second timeout\n    # If another process holds the lock, this will block for up to 5 seconds.\n    # If the lock cannot be acquired, a LockError is raised.\n    with locket.lock_file(lock_file_path, timeout=5):\n        print(f\"Lock acquired on {lock_file_path}. Performing critical action...\")\n        # Simulate work within the critical section\n        time.sleep(2)\n        print(\"Critical action complete. Lock will be released automatically.\")\nexcept locket.LockError:\n    print(f\"Could not acquire lock on {lock_file_path} within the timeout. Another process might hold it.\")\nexcept Exception as e:\n    print(f\"An unexpected error occurred: {e}\")\n\nprint(\"\\nDemonstrating explicit acquire/release (less recommended)...\")\nlock = None\ntry:\n    # Acquire the lock explicitly\n    lock = locket.lock_file(lock_file_path, timeout=1)\n    lock.acquire()\n    print(f\"Lock acquired on {lock_file_path} (manual). Performing critical action...\")\n    time.sleep(1)\n    print(\"Critical action complete (manual).\")\nfinally:\n    # Always ensure the lock is released, even if errors occur\n    if lock:\n        try:\n            lock.release()\n            print(\"Lock released (manual).\")\n        except locket.LockError:\n            print(\"Warning: Attempted to release an already unlocked lock. This should not happen if `release()` is paired with `acquire()`.\")\n","lang":"python","description":"This quickstart demonstrates how to use `locket.lock_file()` with a context manager for safe and automatic lock acquisition and release. It also shows the explicit `acquire()` and `release()` pattern, which requires careful handling to prevent deadlocks or `LockError` if `release()` is called on an unlocked lock. The `timeout` parameter prevents indefinite blocking.","tag":null,"tag_description":null,"last_tested":"2026-04-24","results":[{"runtime":"python:3.10-alpine","exit_code":0},{"runtime":"python:3.10-slim","exit_code":0},{"runtime":"python:3.11-alpine","exit_code":0},{"runtime":"python:3.11-slim","exit_code":0},{"runtime":"python:3.12-alpine","exit_code":0},{"runtime":"python:3.12-slim","exit_code":0},{"runtime":"python:3.13-alpine","exit_code":0},{"runtime":"python:3.13-slim","exit_code":0},{"runtime":"python:3.9-alpine","exit_code":0},{"runtime":"python:3.9-slim","exit_code":0}]},"compatibility":{"tag":"verified","tag_description":"installs cleanly on critical runtimes, fast import, recently 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