gh-134954: Hard-cap max file descriptors in subprocess test fd_status

[itamaro]

On some systems, SC_OPEN_MAX may return a very large value (i.e. 2**30), leading to the subprocess test timing out (or run forever).

Prevent this situation by applying a hard cap on how many file descriptors are checked.

• Issue: test_subprocess can timeout on systems with excessive max file descriptors #134954

[bedevere-bot]

🤖 New build scheduled with the buildbot fleet by @gpshead for commit c534fe5 🤖

Results will be shown at:

https://buildbot.python.org/all/#/grid?branch=refs%2Fpull%2F134955%2Fmerge

If you want to schedule another build, you need to add the 🔨 test-with-buildbots label again.

[gpshead]

good to see some systems finally actually go the "no limits, its not the 90s" route on that value. skim through buildbot results in a few hours - I expect they'll be fine. then feel free to merge.

[itamaro]

skim through buildbot results in a few hours - I expect they'll be fine. then feel free to merge

thanks @gpshead !
I understand the wasm32-wasi Non-Debug PR builder is known to be failing, so should be ok to ignore.
Still waiting for the last 9 PPC64LE builders, but I will need a core dev to click the merge button for me :)

[miss-islington-app]

Thanks @itamaro for the PR, and @gpshead for merging it 🌮🎉.. I'm working now to backport this PR to: 3.13, 3.14.
🐍🍒⛏🤖

[bedevere-app]

GH-134980 is a backport of this pull request to the 3.14 branch.

[bedevere-app]

GH-134981 is a backport of this pull request to the 3.13 branch.

[bedevere-bot]

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot s390x Fedora Stable Refleaks 3.13 (tier-3) has failed when building commit 379c4a2.

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/#/builders/1662/builds/220) and take a look at the build logs.
4. Check if the failure is related to this commit (379c4a2) 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/#/builders/1662/builds/220

Failed tests:

• test.test_asyncio.test_ssl

Failed subtests:

• test_remote_shutdown_receives_trailing_data_on_slow_socket - test.test_asyncio.test_ssl.TestSSL.test_remote_shutdown_receives_trailing_data_on_slow_socket

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

==

Click to see traceback logs

Traceback (most recent call last):
  File "/home/buildbot/buildarea/3.13.cstratak-fedora-stable-s390x.refleak/build/Lib/test/test_asyncio/test_ssl.py", line 1592, in test_remote_shutdown_receives_trailing_data_on_slow_socket
    self.loop.run_until_complete(client(srv.addr))
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^
  File "/home/buildbot/buildarea/3.13.cstratak-fedora-stable-s390x.refleak/build/Lib/asyncio/base_events.py", line 725, in run_until_complete
    return future.result()
           ~~~~~~~~~~~~~^^
  File "/home/buildbot/buildarea/3.13.cstratak-fedora-stable-s390x.refleak/build/Lib/test/test_asyncio/test_ssl.py", line 1576, in client
    await future
  File "/home/buildbot/buildarea/3.13.cstratak-fedora-stable-s390x.refleak/build/Lib/test/test_asyncio/test_ssl.py", line 1584, in wrapper
    meth(sock)
    ~~~~^^^^^^
  File "/home/buildbot/buildarea/3.13.cstratak-fedora-stable-s390x.refleak/build/Lib/test/test_asyncio/test_ssl.py", line 1502, in server
    self.assertEqual(data_len, CHUNK * SIZE*2)
    ~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: 0 != 8388608