Currenly focus is on PyPy3.5 right? will there be continuation of development after PyPy3.5? On Sun, Feb 26, 2017 at 4:59 PM Yury V. Zaytsev <yury@shurup.com> wrote:

On Sun, 26 Feb 2017, Sebastian K via pypy-dev wrote:

...

can someone explain me why pypy needs the gil? In CPython the main reason is the reference counting but pypy doesnt use reference counting.

The main reason is not the reference counting itself, but rather that the garbage collector (which happens to use reference counting) is not thread-safe. It is true that PyPy's garbage collectors do not use reference counting, but in itself, this doesn't make them any thread-safer. On top of that, there are more subtle issues to take care of, so instead of working towards removing the GIL, the decision was made to investigate a completely different approach to parallelization (STM):

http://doc.pypy.org/en/latest/faq.html#does-pypy-have-a-gil-why

-- Sincerely yours, Yury V. Zaytsev _______________________________________________ pypy-dev mailing list pypy-dev@python.org https://mail.python.org/mailman/listinfo/pypy-dev

Hi, On 26 February 2017 at 11:12, Yury V. Zaytsev <yury@shurup.com> wrote:

The main reason is not the reference counting itself, but rather that the garbage collector (which happens to use reference counting) is not thread-safe. It is true that PyPy's garbage collectors do not use reference counting, but in itself, this doesn't make them any thread-safer. On top of that, there are more subtle issues to take care of (...)

To complete that answer, I updated the faq: http://doc.pypy.org/en/latest/faq.html#does-pypy-have-a-gil-why A bientôt, Armin.

Currenly focus is on PyPy3.5 right? will there be continuation of development after PyPy3.5? On Sun, Feb 26, 2017 at 4:59 PM Yury V. Zaytsev <yury@shurup.com> wrote:

On Sun, 26 Feb 2017, Sebastian K via pypy-dev wrote:

...

can someone explain me why pypy needs the gil? In CPython the main reason is the reference counting but pypy doesnt use reference counting.

The main reason is not the reference counting itself, but rather that the garbage collector (which happens to use reference counting) is not thread-safe. It is true that PyPy's garbage collectors do not use reference counting, but in itself, this doesn't make them any thread-safer. On top of that, there are more subtle issues to take care of, so instead of working towards removing the GIL, the decision was made to investigate a completely different approach to parallelization (STM):

http://doc.pypy.org/en/latest/faq.html#does-pypy-have-a-gil-why

-- Sincerely yours, Yury V. Zaytsev _______________________________________________ pypy-dev mailing list pypy-dev@python.org https://mail.python.org/mailman/listinfo/pypy-dev

Hi, On 26 February 2017 at 11:12, Yury V. Zaytsev <yury@shurup.com> wrote:

The main reason is not the reference counting itself, but rather that the garbage collector (which happens to use reference counting) is not thread-safe. It is true that PyPy's garbage collectors do not use reference counting, but in itself, this doesn't make them any thread-safer. On top of that, there are more subtle issues to take care of (...)

To complete that answer, I updated the faq: http://doc.pypy.org/en/latest/faq.html#does-pypy-have-a-gil-why A bientôt, Armin.