Victor Stinner blog 3

Drawing: "L'oeil du cyclone" by Théo Grosjean.

This morning, I got this email from the buildbot-status mailing list:

The Buildbot has detected a new failure on builder PPC64LE Fedora Rawhide Refleaks 3.x while building Python.

I get many of buildbot failures per month (by email), but I like to debug reference leaks: they are more challenging …

The PyObject structure prevents indirectly to optimize CPython. We will see why and how I prepared the C API to make this structure opaque. It took me 1 year and a half to add functions and to introduce incompatible C API changes (fear!).

In February 2020, I started by adding …

I'm trying to enhance and to fix the Python C API for 5 years. My first goal was to shrink the C API without breaking third party C extensions. I hid many private functions from the public functions: I moved them to the "internal C API". I also deprecated and …

In 2020, I created a new pythoncapi_compat project to add Python 3.10 support to C extensions without losing support for old Python versions. It supports Python 2.7-3.10 and PyPy 2.7-3.7. The project is made of two parts:

• pythoncapi_compat.h: Header file providing new C API …

This article is about changes that I made, with the help other developers, in the Python C API in Python 3.8, 3.9 and 3.10 to avoid accessing structures members: prepare the C API to make structures opaque. These changes are related to my PEP 620 "Hide implementation …

This article is about the work done in Python in 2019 and 2020 to better isolate subinterpreters. Static types are converted to heap types, extension modules are converted to use the new multiphase initialization API (PEP 489), caches, states, singletons and free lists are made per-interpreter, many bugs have been …

This article is the history of Python C API discussions over the last 4 years, and the creation of C API projects: pythoncapi website, pythoncapi_compat.h header file and HPy (new clean C API). More and more people are aware of issues caused by the C API and are working …

This article is about old reference leaks discovered or caused by the work on isolating subinterpreters: leaks in 6 different modules (gc, _weakref, _abc, _signal, _ast and _thread).

My previous article Daemon threads and the Python finalization in Python 3.2 and 3.3 introduces issues caused by daemon threads in the Python finalization and past changes to make them work.

This article is about bugfixes of the infamous GIL (Global Interpreter Lock) in Python 3.9, between …