gh-103092: Isolate socket

[erlend-aasland]

• Issue: Isolate Stdlib Extension Modules #103092

[bedevere-bot]

🤖 New build scheduled with the buildbot fleet by @erlend-aasland for commit b4edf64 🤖

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

[erlend-aasland]

There's some leaks that needs to be adressed:

$ ./python.exe measure.pybefore=46451, after=47809before=47811, after=48549before=48549, after=49287before=49287, after=50025before=50025, after=50763

measure.py

importgcimportsysfor_inrange(5):
gc.collect()
before=sys.gettotalrefcount()
import_socketdelsys.modules["_socket"]
del_socketgc.collect()
after=sys.gettotalrefcount()
print(f"{before=}, {after=}")
# assert after == before

... and these two:

$ ./python.exe -m test -R : test_socket -m RecvmsgIntoSCMRightsStreamTest Raised RLIMIT_NOFILE: 256 -> 10240:00:00 load avg: 1.96 Run tests sequentially0:00:00 load avg: 1.96 [1/1] test_socketbeginning 9 repetitions123456789.........test_socket leaked [10, 10, 10, 10] file descriptors, sum=40test_socket failed (reference leak)== Tests result: FAILURE ==1 test failed: test_socketTotal duration: 1.8 secTests result: FAILURE
$ ./python.exe -m test -R : test_socket -m RecvmsgSCMRightsStreamTest Raised RLIMIT_NOFILE: 256 -> 10240:00:00 load avg: 2.52 Run tests sequentially0:00:00 load avg: 2.52 [1/1] test_socketbeginning 9 repetitions123456789.........test_socket leaked [10, 10, 10, 10] file descriptors, sum=40test_socket failed (reference leak)== Tests result: FAILURE ==1 test failed: test_socketTotal duration: 1.8 secTests result: FAILURE

[erlend-aasland]

Regarding #103094 (comment): the file descriptors leak on main as well, so it is not a regression introduced by this PR. Let's not bother with those. There's still references leaked by repeated init of the module, though.

[erlend-aasland]

Seems like the leaks are due to the capsulated C API not being freed.

[erlend-aasland]

I'd like to hold this PR until #103261 has landed.

[bedevere-bot]

🤖 New build scheduled with the buildbot fleet by @erlend-aasland for commit 2019a93 🤖

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

[kumaraditya303]

LGTM