GH-113462: Limit the number of versions that a single class can use.

[markshannon]

Limits the number of versions that a single class can use. Prevents a few wayward classes using up all the version numbers.

• Issue: Incrementing class variable about 2**32 times causes the Python 3.12.1 interpreter to crash #113462

[bedevere-bot]

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot ARM64 MacOS M1 Refleaks NoGIL 3.x has failed when building commit 992446d.

What do you need to do:

1. Don't panic.
2. Check the buildbot page in the devguide if you don't know what the buildbots are or how they work.
3. Go to the page of the buildbot that failed (https://buildbot.python.org/all/#builders/1368/builds/125) and take a look at the build logs.
4. Check if the failure is related to this commit (992446d) or if it is a false positive.
5. If the failure is related to this commit, please, reflect that on the issue and make a new Pull Request with a fix.

You can take a look at the buildbot page here:

https://buildbot.python.org/all/#builders/1368/builds/125

Failed tests:

• test.test_concurrent_futures.test_init

Test leaking resources:

• test_init: memory blocks

Summary of the results of the build (if available):

==

Click to see traceback logs

Traceback (most recent call last):
  File "/Users/ec2-user/buildbot/buildarea/3.x.itamaro-macos-arm64-aws.macos-with-brew.refleak.nogil/build/Lib/multiprocessing/util.py", line 296, in _run_finalizers
    finalizer()
    ~~~~~~~~~^^
  File "/Users/ec2-user/buildbot/buildarea/3.x.itamaro-macos-arm64-aws.macos-with-brew.refleak.nogil/build/Lib/multiprocessing/util.py", line 220, in __call__
    res = self._callback(*self._args, **self._kwargs)
          ~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/ec2-user/buildbot/buildarea/3.x.itamaro-macos-arm64-aws.macos-with-brew.refleak.nogil/build/Lib/multiprocessing/synchronize.py", line 87, in _cleanup
    sem_unlink(name)
    ~~~~~~~~~~^^^^^^
FileNotFoundError: [Errno 2] No such file or directory
Traceback (most recent call last):
  File "/Users/ec2-user/buildbot/buildarea/3.x.itamaro-macos-arm64-aws.macos-with-brew.refleak.nogil/build/Lib/multiprocessing/util.py", line 296, in _run_finalizers
    finalizer()
    ~~~~~~~~~^^
  File "/Users/ec2-user/buildbot/buildarea/3.x.itamaro-macos-arm64-aws.macos-with-brew.refleak.nogil/build/Lib/multiprocessing/util.py", line 220, in __call__
    res = self._callback(*self._args, **self._kwargs)
          ~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/ec2-user/buildbot/buildarea/3.x.itamaro-macos-arm64-aws.macos-with-brew.refleak.nogil/build/Lib/multiprocessing/synchronize.py", line 87, in _cleanup
    sem_unlink(name)
    ~~~~~~~~~~^^^^^^
FileNotFoundError: [Errno 2] No such file or directory
Traceback (most recent call last):
  File "/Users/ec2-user/buildbot/buildarea/3.x.itamaro-macos-arm64-aws.macos-with-brew.refleak.nogil/build/Lib/multiprocessing/util.py", line 296, in _run_finalizers
    finalizer()
    ~~~~~~~~~^^
  File "/Users/ec2-user/buildbot/buildarea/3.x.itamaro-macos-arm64-aws.macos-with-brew.refleak.nogil/build/Lib/multiprocessing/util.py", line 220, in __call__
    res = self._callback(*self._args, **self._kwargs)
          ~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/ec2-user/buildbot/buildarea/3.x.itamaro-macos-arm64-aws.macos-with-brew.refleak.nogil/build/Lib/multiprocessing/synchronize.py", line 87, in _cleanup
    sem_unlink(name)
    ~~~~~~~~~~^^^^^^
FileNotFoundError: [Errno 2] No such file or directory
Traceback (most recent call last):
  File "/Users/ec2-user/buildbot/buildarea/3.x.itamaro-macos-arm64-aws.macos-with-brew.refleak.nogil/build/Lib/multiprocessing/util.py", line 296, in _run_finalizers
    finalizer()
    ~~~~~~~~~^^
  File "/Users/ec2-user/buildbot/buildarea/3.x.itamaro-macos-arm64-aws.macos-with-brew.refleak.nogil/build/Lib/multiprocessing/util.py", line 220, in __call__
    res = self._callback(*self._args, **self._kwargs)
          ~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/ec2-user/buildbot/buildarea/3.x.itamaro-macos-arm64-aws.macos-with-brew.refleak.nogil/build/Lib/multiprocessing/synchronize.py", line 87, in _cleanup
    sem_unlink(name)
    ~~~~~~~~~~^^^^^^
FileNotFoundError: [Errno 2] No such file or directory
Traceback (most recent call last):
  File "/Users/ec2-user/buildbot/buildarea/3.x.itamaro-macos-arm64-aws.macos-with-brew.refleak.nogil/build/Lib/multiprocessing/util.py", line 296, in _run_finalizers
    finalizer()
    ~~~~~~~~~^^
  File "/Users/ec2-user/buildbot/buildarea/3.x.itamaro-macos-arm64-aws.macos-with-brew.refleak.nogil/build/Lib/multiprocessing/util.py", line 220, in __call__
    res = self._callback(*self._args, **self._kwargs)
          ~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/ec2-user/buildbot/buildarea/3.x.itamaro-macos-arm64-aws.macos-with-brew.refleak.nogil/build/Lib/multiprocessing/synchronize.py", line 87, in _cleanup
    sem_unlink(name)
    ~~~~~~~~~~^^^^^^
FileNotFoundError: [Errno 2] No such file or directory
Traceback (most recent call last):
  File "/Users/ec2-user/buildbot/buildarea/3.x.itamaro-macos-arm64-aws.macos-with-brew.refleak.nogil/build/Lib/multiprocessing/util.py", line 296, in _run_finalizers
    finalizer()
    ~~~~~~~~~^^
  File "/Users/ec2-user/buildbot/buildarea/3.x.itamaro-macos-arm64-aws.macos-with-brew.refleak.nogil/build/Lib/multiprocessing/util.py", line 220, in __call__
    res = self._callback(*self._args, **self._kwargs)
          ~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/ec2-user/buildbot/buildarea/3.x.itamaro-macos-arm64-aws.macos-with-brew.refleak.nogil/build/Lib/multiprocessing/synchronize.py", line 87, in _cleanup
    sem_unlink(name)
    ~~~~~~~~~~^^^^^^
FileNotFoundError: [Errno 2] No such file or directory

[vstinner]

Sadly, this change introduced a regression: #119462