cpython: 7f3695701724 (original) (raw)

Mercurial > cpython

changeset 93770:7f3695701724

Issue #22696: Add function :func:`sys.is_finalizing` to know about interpreter shutdown. [#22696]

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--- a/Doc/glossary.rst +++ b/Doc/glossary.rst @@ -402,6 +402,19 @@ Glossary than compiled ones, though their programs generally also run more slowly. See also :term:interactive.

• interpreter shutdown

•  When asked to shut down, the Python interpreter enters a special phase[](#l1.8)

•  where it gradually releases all allocated resources, such as modules[](#l1.9)

•  and various critical internal structures.  It also makes several calls[](#l1.10)

•  to the :term:`garbage collector <garbage collection>`. This can trigger[](#l1.11)

•  the execution of code in user-defined destructors or weakref callbacks.[](#l1.12)

•  Code executed during the shutdown phase can encounter various[](#l1.13)

•  exceptions as the resources it relies on may not function anymore[](#l1.14)

•  (common examples are library modules or the warnings machinery).[](#l1.15)

+

•  The main reason for interpreter shutdown is that the ``__main__`` module[](#l1.17)

•  or the script being run has finished executing.[](#l1.18)

+ iterable An object capable of returning its members one at a time. Examples of iterables include all sequence types (such as :class:list, :class:str,

--- a/Doc/library/gc.rst +++ b/Doc/library/gc.rst @@ -186,7 +186,7 @@ values but should not rebind them): added to this list rather than freed. .. versionchanged:: 3.2

•  If this list is non-empty at interpreter shutdown, a[](#l2.7)

•  If this list is non-empty at :term:`interpreter shutdown`, a[](#l2.8)
   :exc:`ResourceWarning` is emitted, which is silent by default.  If[](#l2.9)
   :const:`DEBUG_UNCOLLECTABLE` is set, in addition all uncollectable objects[](#l2.10)
   are printed.[](#l2.11)

@@ -252,8 +252,8 @@ The following constants are provided for to the garbage list. .. versionchanged:: 3.2

•  Also print the contents of the :data:`garbage` list at interpreter[](#l2.16)

•  shutdown, if it isn't empty.[](#l2.17)

•  Also print the contents of the :data:`garbage` list at[](#l2.18)

•  :term:`interpreter shutdown`, if it isn't empty.[](#l2.19)

.. data:: DEBUG_SAVEALL

--- a/Doc/library/sys.rst +++ b/Doc/library/sys.rst @@ -718,6 +718,14 @@ always available. value of :func:intern around to benefit from it. +.. function:: is_finalizing() +

• Return :const:True if the Python interpreter is
• :term:shutting down <interpreter shutdown>, :const:False otherwise. +
• .. versionadded:: 3.5 +

+ .. data:: last_type last_value last_traceback

--- a/Doc/library/weakref.rst +++ b/Doc/library/weakref.rst @@ -258,7 +258,7 @@ These method have the same issues as the are called in reverse order of creation. A finalizer will never invoke its callback during the later part of

• the interpreter shutdown when module globals are liable to have

• the :term:interpreter shutdown when module globals are liable to have been replaced by :const:None. .. method:: call() @@ -527,8 +527,8 @@ follows::

Starting with Python 3.4, :meth:__del__ methods no longer prevent reference cycles from being garbage collected, and module globals are -no longer forced to :const:None during interpreter shutdown. So this -code should work without any issues on CPython. +no longer forced to :const:None during :term:interpreter shutdown. +So this code should work without any issues on CPython. However, handling of :meth:__del__ methods is notoriously implementation specific, since it depends on internal details of the interpreter's garbage

--- a/Lib/test/test_sys.py +++ b/Lib/test/test_sys.py @@ -744,6 +744,27 @@ class SysModuleTest(unittest.TestCase): c = sys.getallocatedblocks() self.assertIn(c, range(b - 50, b + 50))

• def test_is_finalizing(self):

•    self.assertIs(sys.is_finalizing(), False)[](#l5.8)

•    # Don't use the atexit module because _Py_Finalizing is only set[](#l5.9)

•    # after calling atexit callbacks[](#l5.10)

•    code = """if 1:[](#l5.11)

•        import sys[](#l5.12)

+

•        class AtExit:[](#l5.14)

•            is_finalizing = sys.is_finalizing[](#l5.15)

•            print = print[](#l5.16)

+

•            def __del__(self):[](#l5.18)

•                self.print(self.is_finalizing(), flush=True)[](#l5.19)

+

•        # Keep a reference in the __main__ module namespace, so the[](#l5.21)

•        # AtExit destructor will be called at Python exit[](#l5.22)

•        ref = AtExit()[](#l5.23)

•    """[](#l5.24)

•    rc, stdout, stderr = assert_python_ok('-c', code)[](#l5.25)

•    self.assertEqual(stdout.rstrip(), b'True')[](#l5.26)

+ @test.support.cpython_only class SizeofTest(unittest.TestCase):

--- a/Misc/NEWS +++ b/Misc/NEWS @@ -194,6 +194,9 @@ Core and Builtins Library ------- +- Issue #22696: Add function :func:sys.is_finalizing to know about

• interpreter shutdown. +

• Issue #16043: Add a default limit for the amount of data xmlrpclib.gzip_decode will return. This resolves CVE-2013-1753.

--- a/Python/sysmodule.c +++ b/Python/sysmodule.c @@ -1121,6 +1121,16 @@ PyDoc_STRVAR(sys_clear_type_cache__doc__ "_clear_type_cache() -> None\n[](#l7.4) Clear the internal type lookup cache."); +static PyObject +sys_is_finalizing(PyObject self, PyObject* args) +{

• return PyBool_FromLong(_Py_Finalizing != NULL);

+} + +PyDoc_STRVAR(is_finalizing_doc, +"is_finalizing()\n[](#l7.14) +Return True if Python is exiting."); + static PyMethodDef sys_methods[] = { /* Might as well keep this in alphabetic order / @@ -1167,6 +1177,7 @@ static PyMethodDef sys_methods[] = { getwindowsversion_doc}, #endif / MS_WINDOWS */ {"intern", sys_intern, METH_VARARGS, intern_doc},

• {"is_finalizing", sys_is_finalizing, METH_NOARGS, is_finalizing_doc},

#ifdef USE_MALLOPT {"mdebug", sys_mdebug, METH_VARARGS}, #endif