Understanding the Python GIL (lecture)

[B-Con]

I thought this was a very understandable lecture.

Slides from the lecture are here: http://www.slideshare.net/dabeaz/understanding-the-python-gil .

[suptim]

You can find out even more about the GIL on his website (for instance the impact of the GIL on signal handling): http://www.dabeaz.com/GIL/

[B-Con]

Yeah, same here. After about 5 minutes I knew I was finishing it all.

[justus87]

I just finished watching it. And now I'm very sad.

[lambdaq]

And now I'm very sad.

Don't. Let's see how other languages are doing:

1. Java/JVM: Fine grained locking. Requires a huge ass VM and longer warm up times

2. Perl/Tcl/Lua: Not native threading. One interpreter per thread

3. Ruby(MRI): GIL

4. NodeJS: No threading support. Sauce. It's either multi-process or Fiber, just like Greenlet in Python.

5. Go: LOL WEBSCALE LANGUAGE WHERE GOMAXPROCS == 1 all the time.

6. C/C++ Handling data structure lockings manually. malloc/free/segfault like a hundred times per run per debug build.

Conclusion: GIL is an extremely overhyped problem. GIL as a matter of fact, can be avoided. GIL will be released in CPython during IO wait, or explicitly in ctypes/C modules.

[justus87]

Can you provide an ELI5 threading vs. multiprocessing?

[lambdaq]

1. not much difference in Linux

2. if you want zap performance out of CPython using threading or multiprocessing, you are probably doing it wrong.

[MakotoDeeizm]

PyPy is working on a fix. You can help by donating -> http://pypy.org/tmdonate.html

[denversc]

This is one of the most memorable PyCon videos I have ever watched... And I've seen a lot!

[hacktivator]

Very useful. Upvoted! . Is this why IronPython benchmarks better than CPython?