Re: "White House to Developers: Using C or C++ Invites Cybersecurity Risks"

On 29.04.2024 03:05, Lawrence D'Oliveiro wrote:

On Fri, 8 Mar 2024 14:41:16 +0200, Paavo Helde wrote:
 

AFAIK CPython uses reference counting ...

 Combination of reference-counting as a first resort, with full garbage
collection to deal with those less common cases where you have reference
cycles. Trying to get the best of both worlds.
 The trouble with reference-counting is it impacts multithreading
performance.

Maybe only in case of heavy contention. If there is little contention and the reference counter is implemented as an atomic variable, there is no measurable hit on performance. I know this because I was suspicious myself and measured this recently.
Anyway, multithreading performance is a non-issue for Python so far as the Python interpreter runs in a single-threaded regime anyway, under a global GIL lock. They are planning to get rid of GIL, but this work is still in development AFAIK. I'm sure it will take years to stabilize the whole Python zoo without GIL.
However, the CPython developers have a scheme to deal with

this, by making the reference counts a little less deterministic (i.e.
there may be a slight delay before they become fully correct). I think
this is a complicated idea, and it may take them some time to get it fully
implemented.