Tuesday, May 21, 2013

PyPy 2.0.2 - Fermi Panini

We're pleased to announce PyPy 2.0.2. This is a stable bugfix release over 2.0 and 2.0.1. You can download it here:


It fixes a crash in the JIT when calling external C functions (with ctypes/cffi) in a multithreaded context.

What is PyPy?

PyPy is a very compliant Python interpreter, almost a drop-in replacement for CPython 2.7. It's fast (pypy 2.0 and cpython 2.7.3 performance comparison) due to its integrated tracing JIT compiler.

This release supports x86 machines running Linux 32/64, Mac OS X 64 or Windows 32. Support for ARM is progressing but not bug-free yet.


This release contains only the fix described above. A crash (or wrong results) used to occur if all these conditions were true:

  • your program is multithreaded;
  • it runs on a single-core machine or a heavily-loaded multi-core one;
  • it uses ctypes or cffi to issue external calls to C functions.

This was fixed in the branch emit-call-x86 (see the example file bug1.py).

Cheers, arigo et. al. for the PyPy team