digital-garbageandClaude Opus 5
729027d7e1
Native crashes print a Python traceback instead of nothing, and kill -USR1 dumps every thread's stack from a hung process without attaching anything or restarting it. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
78 lines
2.5 KiB
Python
78 lines
2.5 KiB
Python
"""Turning a silent death into a traceback.
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Two failures this project has actually hit leave nothing in the log: a native crash (no
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Python traceback at all) and a hang (nothing to print by definition). faulthandler covers
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both — the crash handlers dump the stack before dying, and SIGUSR1 dumps it on demand from
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another terminal without restarting anything.
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"""
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import sys
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import types
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from pathlib import Path
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import pytest
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sys.path.insert(0, str(Path(__file__).resolve().parents[1]))
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import diagnostics as dg # noqa: E402
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class _FH:
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def __init__(self, fail=False):
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self.enabled = None
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self.registered = []
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self._fail = fail
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def enable(self, **kw):
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if self._fail:
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raise RuntimeError("no can do")
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self.enabled = kw
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def register(self, signum, **kw):
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self.registered.append((signum, kw))
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@pytest.mark.parametrize("text", ["1", "true", "yes", "on", "ENABLE", " Enabled "])
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def test_the_on_words(text):
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assert dg.wanted(text)
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@pytest.mark.parametrize("text", ["", None, "0", "off", "no", "maybe"])
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def test_everything_else_is_off(text):
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assert not dg.wanted(text)
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def test_it_does_nothing_unless_asked():
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"""Installing signal handlers in someone else's process should be a choice."""
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fh = _FH()
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assert dg.enable("", fh=fh) is None
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assert fh.enabled is None and fh.registered == []
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def test_it_installs_the_crash_handlers_for_every_thread():
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fh = _FH()
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note = dg.enable("1", fh=fh, sig=types.SimpleNamespace())
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assert fh.enabled["all_threads"] is True
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assert "native crash" in note
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def test_sigusr1_dumps_a_hung_process_on_demand():
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"""The half that matters for a hang: no py-spy, no gdb, no restart."""
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fh = _FH()
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note = dg.enable("1", fh=fh, sig=types.SimpleNamespace(SIGUSR1=10))
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assert fh.registered and fh.registered[0][0] == 10
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assert fh.registered[0][1]["all_threads"] is True
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assert "kill -USR1" in note
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def test_no_sigusr1_is_not_an_error():
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"""Windows has no SIGUSR1; the crash handler is still the part that matters there."""
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fh = _FH()
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note = dg.enable("1", fh=fh, sig=types.SimpleNamespace())
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assert fh.registered == [] and "kill -USR1" not in note and note
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def test_a_broken_faulthandler_never_breaks_the_import():
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"""This runs at import. A diagnostic that stops FunPack loading is worse than none."""
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note = dg.enable("1", fh=_FH(fail=True), sig=types.SimpleNamespace())
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assert "could not be enabled" in note
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