fastrlock

library0.8.3pypypi✓ verified 26d ago

Fastrlock is a C-level implementation of a re-entrant, optimistic lock for CPython, serving as a drop-in replacement for `threading.RLock`. Implemented in Cython, it offers both a Python and a C-API, designed to optimize for non-congested locking scenarios. It is actively maintained with periodic updates to support newer Python versions, with its current version being 0.8.3.

database

pip install fastrlock

github ↗package ↗

INSTALL

IMPORT

SIG · FASTRLOCK

fastrlock

databasepythonv0.8.3

Install

1.6s avg

Import

—

Disk

16MB

Pass rate

10/ 10

Env Coverage10 / 10

glibc

3.9–3.13

musl

3.9–3.13

Install & Compatibility

Where this runs

tested against v0.8.3 · pip install

no network on importno background threads

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

py 3.10–3.95 runs

installs and imports cleanly · install 0.0s · import 0.000s · 17.9MB

glibc

py 3.10–3.95 runs

installs and imports cleanly · install 1.6s · import 0.000s · 18MB

16MB installed

● package 16MB

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

rlock

✓ from fastrlock import rlock

Initialize and use `fastrlock.rlock()` as a direct replacement for `threading.RLock`. It supports the context manager protocol (`with lock:`).

import threading from fastrlock import rlock def worker(lock, name): print(f"{name}: Trying to acquire lock...") with lock: print(f"{name}: Lock acquired. Doing work...") # Simulate re-entrant acquisition with lock: print(f"{name}: Lock re-acquired internally.") print(f"{name}: Work done, releasing lock.") # Using fastrlock fast_lock = rlock() thread1 = threading.Thread(target=worker, args=(fast_lock, "Thread A")) thread2 = threading.Thread(target=worker, args=(fast_lock, "Thread B")) thread1.start() thread2.start() thread1.join() thread2.join() print("All threads finished.")

Debug

Known issues

gotchaPerformance comparison with `threading.RLock` in Python 3.4+ may be mixed. While `fastrlock` is generally faster in Python 2.7 and through its Cython API, for Python 3.4 and later, the standard library's `threading.RLock` can be as fast or even faster when called through the Python API.

fix

Benchmark your specific use case if performance is critical. Consider using the Cython C-API for maximum performance benefits if integrating with other Cython modules.

affects: 3.4+

deprecatedOfficial Python 2 support has been removed, although Linux wheels for Python 2 might still be built for legacy reasons. New development focuses on Python 3.

fix

Upgrade to Python 3.7+ and use a recent version of `fastrlock` for official support and continued updates.

affects: <=0.7 (official support removed from 0.8+)

breakingVersion 0.7 included an adaptation for unsigned thread IDs, which are used by Python 3.7 and newer. While primarily an internal change, using versions prior to 0.7 with Python 3.7+ could potentially lead to unexpected behavior related to thread identification.

fix

Ensure you are using `fastrlock` version 0.7 or later when developing for Python 3.7 and above.

affects: <0.7 with Python 3.7+

gotchaThe primary performance benefit of `fastrlock` in modern Python versions (3.4+) is realized when utilizing its C-API directly from other Cython modules, as this avoids Python call overhead. Using it purely through its Python API might yield less significant or no performance gains compared to the standard library's `threading.RLock`.

fix

If integrating with Cython code, leverage `from fastrlock cimport rlock` for optimal performance. Otherwise, carefully consider if the Python API provides sufficient benefits for your specific workload.

affects: All versions on Python 3.4+

Errors

Common errors & fixes

error: Microsoft Visual C++ 14.0 is required.

This error occurs on Windows when attempting to install fastrlock via pip, as it is a Cython-implemented library that requires compilation with the Microsoft Visual C++ Build Tools.

fix

Install the 'Desktop development with C++' workload, including the 'MSVC v143 - VS 2022 C++ x64/x86 build tools' (or equivalent for your Visual Studio version) from the Visual Studio Installer, or download the Microsoft Visual C++ Build Tools separately from the official Visual Studio website.

ModuleNotFoundError: No module named 'fastrlock'

This error indicates that the 'fastrlock' package is not installed in the Python environment or Python cannot find it in its search path.

fix

Ensure fastrlock is correctly installed by running `pip install fastrlock`. If using a virtual environment, ensure it's activated, and the installation is successful.

ImportError: cannot import name 'RLock' from 'fastrlock'

Users attempting to import `RLock` (with a capital 'R') directly from the `fastrlock` package will encounter this error because the main re-entrant lock class provided by the library is named `FastRLock`, or can be imported as `rlock` (lowercase) for direct use.

fix

Import the correct class as `from fastrlock import FastRLock` to use the class directly, or `from fastrlock import rlock` if you're importing the module-level instance, and then use `FastRLock()` or `rlock` respectively.

TypeError: 'module' object is not callable

This error happens when a user tries to call the `fastrlock` module itself as if it were a function or class, instead of instantiating the `FastRLock` class within it.

fix

To create a lock, you need to instantiate the `FastRLock` class. The correct way is `from fastrlock import FastRLock; lock = FastRLock()` or `import fastrlock; lock = fastrlock.FastRLock()`.

Upgrade

Version history

0.8.3latest on PyPI · released Dec 17, 2024

Audit

Dependencies

pythonrequiredRequires CPython 3.7+; specific wheels for 0.8.3 support Python 3.13+ directly. Older versions may have less broad compatibility.

libc6requiredA core GNU C Library dependency, common on Linux systems.

cythonoptionalRequired for building from source distribution; not a runtime dependency when installing pre-built wheels.

Agent activity

13 hits · last 30 days

node

Resources

githubhttps://github.com/scoder/fastrlock ↗

packagehttps://pypi.org/project/fastrlock/ ↗