Fixes #220: Change worker exception to BaseException

[dxdc]

Summary

See: #220

There may be more work required as I'm not sure how extensively these changes need to be propagated. I'm happy to add tests, etc. but I am not very familiar with the project structure and it seems the code is duplicated into multiple places.

Checklist

Documentation and Tests

• Added relevant tests that run with python tests/__main__.py, and pass.
• Added relevant documentation that builds in sphinx without error.
• Added new features that are documented with examples.
• Artifacts produced with the main branch work as expected under this PR.

Release Management

• Added "Fixes #NNN" in the PR body, referencing the issue (#NNN) it closes.
• Added a comment to issue #NNN, linking back to this PR.
• Added rationale for any breakage of backwards compatibility.
• Requested a review.

[mmckerns]

The code mirrors the stdlib multiprocessing, so there's a "directory" for each major version of python (and also pypy), with a fork of multiprocessing in each from the corresponding version. You edited py3.11, which is the fork for python 3.11. So, often an edit needs to be duplicated across a few versions of python (i.e. directories). Since the code is forked, the tests are also forked... so for python 3.11, the tests are at py3.11/multiprocess/tests

[dxdc]

@mmckerns ok thanks. I'm not sure how to get the tests to pass, as I'm not very familiar with this library. but these tests definitely seem to hang.

    def test_map_sigterm_base_exception(self):
        def _sigterm_worker(x):
            def _handler(signum, frame):
                raise SystemExit(f"worker received SIGTERM on input={x}")
        
            signal.signal(signal.SIGTERM, _handler)
            os.kill(os.getpid(), signal.SIGTERM)

        try:
            self.pool.map_async(_sigterm_worker, list(range(3))).get(timeout=SHUTDOWN_TIMEOUT)
        except multiprocessing.TimeoutError:
            self.fail("pool.map_async with sigterm stalled on base exception")

    def test_imap_sigterm_base_exception(self):
        def _sigterm_worker(x):
            def _handler(signum, frame):
                raise SystemExit(f"worker received SIGTERM on input={x}")
        
            signal.signal(signal.SIGTERM, _handler)
            os.kill(os.getpid(), signal.SIGTERM)

        try:
            for _ in self.pool.imap(_sigterm_worker, list(range(3))):
                pass
        except multiprocessing.TimeoutError:
            self.fail("pool.map_async with sigterm stalled on base exception")

[dxdc]

@mmckerns any chance you could review this again? I made the other changes

[dxdc]

@mmckerns just bumping this in case it got buried — whenever you have a chance, I’d appreciate another look. Thanks!