test_perf_profiler: race condition when cleaning up perf-*.map files

[pareshjoshij]

Bug report

Bug description:

What happens

Lib/test/test_perf_profiler.py uses setUp/tearDown to record all perf-*.map files in /tmp at test start, then deletes any new ones at the end.

When tests run in parallel (make -j, CI runners, pytest-xdist), one test deletes map files belonging to another test → race condition.

This causes:

• Flaky test failures
• Leftover /tmp/perf-*.map files
• Unreliable CI results

What should happen

Each test should only delete the perf-*.map file(s) it created, regardless of other concurrent processes.

CPython versions tested on:

CPython main branch

Operating systems tested on:

No response

Linked PRs

• gh-141592: test_perf_profiler: fix race in perf map cleanup using addCleanup #141593

[picnixz]

Can't we just change the name of the temporary file with a per-process ID?

[pareshjoshij]

Thanks for the review, @picnixz!

Can't we just change the name of the temporary file with a per-process ID?

The perf-*.map files are not created by our test — they are written directly by the Python interpreter when -Xperf is used.

From the implementation:

// Objects/perf_trampoline.c
snprintf(path, sizeof(path), "/tmp/perf-%d.map", getpid());