diff options
| -rw-r--r-- | Doc/whatsnew/3.8.rst | 9 | ||||
| -rw-r--r-- | Lib/_pyio.py | 23 | ||||
| -rw-r--r-- | Lib/test/test_io.py | 64 |
3 files changed, 51 insertions, 45 deletions
diff --git a/Doc/whatsnew/3.8.rst b/Doc/whatsnew/3.8.rst index 8c2b40d..b91f7bc 100644 --- a/Doc/whatsnew/3.8.rst +++ b/Doc/whatsnew/3.8.rst @@ -318,6 +318,15 @@ for :func:`property`, :func:`classmethod`, and :func:`staticmethod`:: self.bit_rate = round(bit_rate / 1000.0, 1) self.duration = ceil(duration) +io +-- + +In development mode (:option:`-X` ``env``) and in debug build, the +:class:`io.IOBase` finalizer now logs the exception if the ``close()`` method +fails. The exception is ignored silently by default in release build. +(Contributed by Victor Stinner in :issue:`18748`.) + + gc -- diff --git a/Lib/_pyio.py b/Lib/_pyio.py index af2ce30..be5e426 100644 --- a/Lib/_pyio.py +++ b/Lib/_pyio.py @@ -33,6 +33,10 @@ DEFAULT_BUFFER_SIZE = 8 * 1024 # bytes # Rebind for compatibility BlockingIOError = BlockingIOError +# Does io.IOBase finalizer log the exception if the close() method fails? +# The exception is ignored silently by default in release build. +_IOBASE_EMITS_UNRAISABLE = (hasattr(sys, "gettotalrefcount") or sys.flags.dev_mode) + def open(file, mode="r", buffering=-1, encoding=None, errors=None, newline=None, closefd=True, opener=None): @@ -378,15 +382,18 @@ class IOBase(metaclass=abc.ABCMeta): def __del__(self): """Destructor. Calls close().""" - # The try/except block is in case this is called at program - # exit time, when it's possible that globals have already been - # deleted, and then the close() call might fail. Since - # there's nothing we can do about such failures and they annoy - # the end users, we suppress the traceback. - try: + if _IOBASE_EMITS_UNRAISABLE: self.close() - except: - pass + else: + # The try/except block is in case this is called at program + # exit time, when it's possible that globals have already been + # deleted, and then the close() call might fail. Since + # there's nothing we can do about such failures and they annoy + # the end users, we suppress the traceback. + try: + self.close() + except: + pass ### Inquiries ### diff --git a/Lib/test/test_io.py b/Lib/test/test_io.py index dc44e50..2c3bf89 100644 --- a/Lib/test/test_io.py +++ b/Lib/test/test_io.py @@ -67,9 +67,9 @@ MEMORY_SANITIZER = ( '--with-memory-sanitizer' in _config_args ) -# Does io.IOBase logs unhandled exceptions on calling close()? -# They are silenced by default in release build. -DESTRUCTOR_LOG_ERRORS = (hasattr(sys, "gettotalrefcount") or sys.flags.dev_mode) +# Does io.IOBase finalizer log the exception if the close() method fails? +# The exception is ignored silently by default in release build. +IOBASE_EMITS_UNRAISABLE = (hasattr(sys, "gettotalrefcount") or sys.flags.dev_mode) def _default_chunk_size(): @@ -1098,23 +1098,18 @@ class CommonBufferedTests: # Test that the exception state is not modified by a destructor, # even if close() fails. rawio = self.CloseFailureIO() - def f(): - self.tp(rawio).xyzzy - with support.captured_output("stderr") as s: - self.assertRaises(AttributeError, f) - s = s.getvalue().strip() - if s: - # The destructor *may* have printed an unraisable error, check it - lines = s.splitlines() - if DESTRUCTOR_LOG_ERRORS: - self.assertEqual(len(lines), 5) - self.assertTrue(lines[0].startswith("Exception ignored in: "), lines) - self.assertEqual(lines[1], "Traceback (most recent call last):", lines) - self.assertEqual(lines[4], 'OSError:', lines) - else: - self.assertEqual(len(lines), 1) - self.assertTrue(lines[-1].startswith("Exception OSError: "), lines) - self.assertTrue(lines[-1].endswith(" ignored"), lines) + try: + with support.catch_unraisable_exception() as cm: + with self.assertRaises(AttributeError): + self.tp(rawio).xyzzy + + if not IOBASE_EMITS_UNRAISABLE: + self.assertIsNone(cm.unraisable) + elif cm.unraisable is not None: + self.assertEqual(cm.unraisable.exc_type, OSError) + finally: + # Explicitly break reference cycle + cm = None def test_repr(self): raw = self.MockRawIO() @@ -2859,23 +2854,18 @@ class TextIOWrapperTest(unittest.TestCase): # Test that the exception state is not modified by a destructor, # even if close() fails. rawio = self.CloseFailureIO() - def f(): - self.TextIOWrapper(rawio).xyzzy - with support.captured_output("stderr") as s: - self.assertRaises(AttributeError, f) - s = s.getvalue().strip() - if s: - # The destructor *may* have printed an unraisable error, check it - lines = s.splitlines() - if DESTRUCTOR_LOG_ERRORS: - self.assertEqual(len(lines), 5) - self.assertTrue(lines[0].startswith("Exception ignored in: "), lines) - self.assertEqual(lines[1], "Traceback (most recent call last):", lines) - self.assertEqual(lines[4], 'OSError:', lines) - else: - self.assertEqual(len(lines), 1) - self.assertTrue(lines[-1].startswith("Exception OSError: "), lines) - self.assertTrue(lines[-1].endswith(" ignored"), lines) + try: + with support.catch_unraisable_exception() as cm: + with self.assertRaises(AttributeError): + self.TextIOWrapper(rawio).xyzzy + + if not IOBASE_EMITS_UNRAISABLE: + self.assertIsNone(cm.unraisable) + elif cm.unraisable is not None: + self.assertEqual(cm.unraisable.exc_type, OSError) + finally: + # Explicitly break reference cycle + cm = None # Systematic tests of the text I/O API |