Merge pull request #8260 from nicoddemus/faulthandler-mode-X-8258

1 files changed, 58 insertions, 77 deletions

diff --git a/src/_pytest/faulthandler.py b/src/_pytest/faulthandler.py
index ff673b5b1..c8eb03101 100644
--- a/src/_pytest/faulthandler.py
+++ b/src/_pytest/faulthandler.py
@@ -12,6 +12,7 @@ from _pytest.store import StoreKey
 
 
 fault_handler_stderr_key = StoreKey[TextIO]()
+fault_handler_originally_enabled_key = StoreKey[bool]()
 
 
 def pytest_addoption(parser: Parser) -> None:
@@ -25,92 +26,72 @@ def pytest_addoption(parser: Parser) -> None:
 def pytest_configure(config: Config) -> None:
     import faulthandler
 
-    if not faulthandler.is_enabled():
-        # faulthhandler is not enabled, so install plugin that does the actual work
-        # of enabling faulthandler before each test executes.
-        config.pluginmanager.register(FaultHandlerHooks(), "faulthandler-hooks")
-    else:
-        # Do not handle dumping to stderr if faulthandler is already enabled, so warn
-        # users that the option is being ignored.
-        timeout = FaultHandlerHooks.get_timeout_config_value(config)
-        if timeout > 0:
-            config.issue_config_time_warning(
-                pytest.PytestConfigWarning(
-                    "faulthandler module enabled before pytest configuration step, "
-                    "'faulthandler_timeout' option ignored"
-                ),
-                stacklevel=2,
-            )
-
-
-class FaultHandlerHooks:
-    """Implements hooks that will actually install fault handler before tests execute,
-    as well as correctly handle pdb and internal errors."""
-
-    def pytest_configure(self, config: Config) -> None:
-        import faulthandler
+    stderr_fd_copy = os.dup(get_stderr_fileno())
+    config._store[fault_handler_stderr_key] = open(stderr_fd_copy, "w")
+    config._store[fault_handler_originally_enabled_key] = faulthandler.is_enabled()
+    faulthandler.enable(file=config._store[fault_handler_stderr_key])
 
-        stderr_fd_copy = os.dup(self._get_stderr_fileno())
-        config._store[fault_handler_stderr_key] = open(stderr_fd_copy, "w")
-        faulthandler.enable(file=config._store[fault_handler_stderr_key])
 
-    def pytest_unconfigure(self, config: Config) -> None:
-        import faulthandler
+def pytest_unconfigure(config: Config) -> None:
+    import faulthandler
 
-        faulthandler.disable()
-        # close our dup file installed during pytest_configure
-        # re-enable the faulthandler, attaching it to the default sys.stderr
-        # so we can see crashes after pytest has finished, usually during
-        # garbage collection during interpreter shutdown
+    faulthandler.disable()
+    # Close the dup file installed during pytest_configure.
+    if fault_handler_stderr_key in config._store:
         config._store[fault_handler_stderr_key].close()
         del config._store[fault_handler_stderr_key]
-        faulthandler.enable(file=self._get_stderr_fileno())
+    if config._store.get(fault_handler_originally_enabled_key, False):
+        # Re-enable the faulthandler if it was originally enabled.
+        faulthandler.enable(file=get_stderr_fileno())
+
+
+def get_stderr_fileno() -> int:
+    try:
+        fileno = sys.stderr.fileno()
+        # The Twisted Logger will return an invalid file descriptor since it is not backed
+        # by an FD. So, let's also forward this to the same code path as with pytest-xdist.
+        if fileno == -1:
+            raise AttributeError()
+        return fileno
+    except (AttributeError, io.UnsupportedOperation):
+        # pytest-xdist monkeypatches sys.stderr with an object that is not an actual file.
+        # https://docs.python.org/3/library/faulthandler.html#issue-with-file-descriptors
+        # This is potentially dangerous, but the best we can do.
+        return sys.__stderr__.fileno()
+
+
+def get_timeout_config_value(config: Config) -> float:
+    return float(config.getini("faulthandler_timeout") or 0.0)
+
+
+@pytest.hookimpl(hookwrapper=True, trylast=True)
+def pytest_runtest_protocol(item: Item) -> Generator[None, None, None]:
+    timeout = get_timeout_config_value(item.config)
+    stderr = item.config._store[fault_handler_stderr_key]
+    if timeout > 0 and stderr is not None:
+        import faulthandler
 
-    @staticmethod
-    def _get_stderr_fileno():
+        faulthandler.dump_traceback_later(timeout, file=stderr)
         try:
-            fileno = sys.stderr.fileno()
-            # The Twisted Logger will return an invalid file descriptor since it is not backed
-            # by an FD. So, let's also forward this to the same code path as with pytest-xdist.
-            if fileno == -1:
-                raise AttributeError()
-            return fileno
-        except (AttributeError, io.UnsupportedOperation):
-            # pytest-xdist monkeypatches sys.stderr with an object that is not an actual file.
-            # https://docs.python.org/3/library/faulthandler.html#issue-with-file-descriptors
-            # This is potentially dangerous, but the best we can do.
-            return sys.__stderr__.fileno()
-
-    @staticmethod
-    def get_timeout_config_value(config):
-        return float(config.getini("faulthandler_timeout") or 0.0)
-
-    @pytest.hookimpl(hookwrapper=True, trylast=True)
-    def pytest_runtest_protocol(self, item: Item) -> Generator[None, None, None]:
-        timeout = self.get_timeout_config_value(item.config)
-        stderr = item.config._store[fault_handler_stderr_key]
-        if timeout > 0 and stderr is not None:
-            import faulthandler
-
-            faulthandler.dump_traceback_later(timeout, file=stderr)
-            try:
-                yield
-            finally:
-                faulthandler.cancel_dump_traceback_later()
-        else:
             yield
+        finally:
+            faulthandler.cancel_dump_traceback_later()
+    else:
+        yield
 
-    @pytest.hookimpl(tryfirst=True)
-    def pytest_enter_pdb(self) -> None:
-        """Cancel any traceback dumping due to timeout before entering pdb."""
-        import faulthandler
 
-        faulthandler.cancel_dump_traceback_later()
+@pytest.hookimpl(tryfirst=True)
+def pytest_enter_pdb() -> None:
+    """Cancel any traceback dumping due to timeout before entering pdb."""
+    import faulthandler
 
-    @pytest.hookimpl(tryfirst=True)
-    def pytest_exception_interact(self) -> None:
-        """Cancel any traceback dumping due to an interactive exception being
-        raised."""
-        import faulthandler
+    faulthandler.cancel_dump_traceback_later()
+
+
+@pytest.hookimpl(tryfirst=True)
+def pytest_exception_interact() -> None:
+    """Cancel any traceback dumping due to an interactive exception being
+    raised."""
+    import faulthandler
 
-        faulthandler.cancel_dump_traceback_later()
+    faulthandler.cancel_dump_traceback_later()