CODEWITHSUNDEEP
pythonmultithreadingconcurrency
jamieb
jamieb

Reputation: 10033

How have other languages overcame the limitations of Python's GIL?

As the industry trends to "web scale" application architecture (as much as I hate buzz words), I know Python has caught a lot of criticism for how the GIL handles concurrency and becomes a bottleneck. I understand the problem on the surface, but not well enough to know how other procedural languages handle threads under the hood. Does Java have similar problems? C#? Ruby? If not, why hasn't Python adopted the same strategy?

Upvotes: 3

Views: 366

Answers (1)

Gareth Latty
Gareth Latty

Reputation: 89067

The GIL exists because it's needed (mainly) for CPython's implementation of reference counting - it's method of garbage collection. So let's be clear, Python doesn't have a GIL, the reference implementation does, and it's just an implementation detail.

The GIL exists because it makes the implementation simple and fast, and most of the time, it simply doesn't matter. Threading is mainly designed to allow access to slow resources alongside processing, which isn't hindered at all by the GIL.

The only reason that the GIL can be an issue is where one wants to do a lot of parallel computation. In this case, one can make an extension module in C or use the multiprocessing module to side-step the GIL.

All this means that the GIL really isn't an issue 99.9% of the time, and when it is, it's easily worked around. If you find it really hinders you, then you might want to try Jython, which is implemented on top of the JVM and uses a different method of garbage collection that doesn't require the GIL.

As always, premature optimization is a bad idea - if you develop something and find yourself hurt by the GIL, then there are ways to work around it without much pain. That said, it's highly unlikely you'll find it's a problem in the real-world. It's one of the most overblown things surrounding Python (maybe second only to the whole indentation thing).

Upvotes: 7

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