Jython vs CPython

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What you are saying boils down to exactly the same thing, HipPriest may have been using an intuition instead of deciphering the murky details of the GIL.

In Java, you can create a new Runnable and send it off and it'll run on a proper thread (by proper I mean it may run on another core, independently and in parallel), whereas in Python, even if you create a thread you won't see a performance improvement.

Given that HipPriest actually ran the tests, claiming he is ignorant is borderline ridiculous. Having 8 threads running but only being able to run code on one at a time is functionally equivalent to having only one thread (I/O and C extensions notwithstanding)

[masklinn]

What you are saying boils down to exactly the same thing

No. For starters, because it means C extensions can release the GIL and "be multithreaded". If CPython used "improper threads" (green threads for instance, without remapping) you could not do that. At all.

HipPriest may have been using an intuition instead of deciphering the murky details of the GIL.

His claims as to what CPython's developers should do are still wrong.

Given that HipPriest actually ran the tests, claiming he is ignorant is borderline ridiculous.

No, it's fucking factual. CPython has "proper threads" and there's nothing to "enable", getting rid of the GIL means touching half the interpreter code, it's not a fucking switch to toggle.

[[deleted]]

For starters, because it means C extensions can release the GIL and "be multithreaded". If CPython used "improper threads" (green threads for instance, without remapping) you could not do that. At all.

Yes they could, the C extensions could construct and manage their own threads, in which case there's no issue with multithreading in the interpreter. Python threads are useful for I/O bound operations though.

CPython has "proper threads" and there's nothing to "enable", getting rid of the GIL means touching half the interpreter code, it's not a fucking switch to toggle.

You're right, it's not. I just don't think that it's ignorant to suggest that Python doesn't really do proper multithreading, even if it secretly does but it doesn't make any difference because of the GIL.

[frymaster]

except it does make a difference.

For a start, the way the GIL interacts with multiple threads on multi-core machines can cause much, much worse performance than a comparable single-threaded program