Add a new warning gategory, ResourceWarning, as discussed on python-dev. It is silent by default,
except when configured --with-pydebug.
Emit this warning from the GC shutdown procedure, rather than just printing to stderr.
diff --git a/Doc/library/exceptions.rst b/Doc/library/exceptions.rst
index 49b5b93..9d77698 100644
--- a/Doc/library/exceptions.rst
+++ b/Doc/library/exceptions.rst
@@ -410,10 +410,20 @@
Base class for warnings related to Unicode.
+
.. exception:: BytesWarning
Base class for warnings related to :class:`bytes` and :class:`buffer`.
+
+.. exception:: ResourceWarning
+
+ Base class for warnings related to resource usage.
+
+ .. versionadded:: 3.2
+
+
+
Exception hierarchy
-------------------
diff --git a/Doc/library/gc.rst b/Doc/library/gc.rst
index ae615eb..0281bb7 100644
--- a/Doc/library/gc.rst
+++ b/Doc/library/gc.rst
@@ -174,17 +174,15 @@
with :meth:`__del__` methods, and *garbage* can be examined in that case to
verify that no such cycles are being created.
- If :const:`DEBUG_SAVEALL` is set, then all unreachable objects will be added to
- this list rather than freed.
+ If :const:`DEBUG_SAVEALL` is set, then all unreachable objects will be added
+ to this list rather than freed.
.. versionchanged:: 3.2
- If this list is non-empty at interpreter shutdown, a warning message
- gets printed.
+ If this list is non-empty at interpreter shutdown, a
+ :exc:`ResourceWarning` is emitted, which is silent by default. If
+ :const:`DEBUG_UNCOLLECTABLE` is set, in addition all uncollectable objects
+ are printed.
- ::
-
- gc: 2 uncollectable objects at shutdown:
- Use gc.set_debug(gc.DEBUG_UNCOLLECTABLE) to list them.
The following constants are provided for use with :func:`set_debug`:
@@ -203,12 +201,12 @@
.. data:: DEBUG_UNCOLLECTABLE
Print information of uncollectable objects found (objects which are not
- reachable but cannot be freed by the collector). These objects will be added to
- the ``garbage`` list.
+ reachable but cannot be freed by the collector). These objects will be added
+ to the ``garbage`` list.
.. versionchanged:: 3.2
Also print the contents of the :data:`garbage` list at interpreter
- shutdown (rather than just its length), if it isn't empty.
+ shutdown, if it isn't empty.
.. data:: DEBUG_SAVEALL
diff --git a/Doc/library/warnings.rst b/Doc/library/warnings.rst
index 309fec5..64689ad 100644
--- a/Doc/library/warnings.rst
+++ b/Doc/library/warnings.rst
@@ -82,6 +82,9 @@
| :exc:`BytesWarning` | Base category for warnings related to |
| | :class:`bytes` and :class:`buffer`. |
+----------------------------------+-----------------------------------------------+
+| :exc:`ResourceWarning` | Base category for warnings related to |
+| | resource usage. |
++----------------------------------+-----------------------------------------------+
While these are technically built-in exceptions, they are documented here,
diff --git a/Include/pyerrors.h b/Include/pyerrors.h
index 58a3df7..25843c3 100644
--- a/Include/pyerrors.h
+++ b/Include/pyerrors.h
@@ -170,6 +170,7 @@
PyAPI_DATA(PyObject *) PyExc_ImportWarning;
PyAPI_DATA(PyObject *) PyExc_UnicodeWarning;
PyAPI_DATA(PyObject *) PyExc_BytesWarning;
+PyAPI_DATA(PyObject *) PyExc_ResourceWarning;
/* Convenience functions */
diff --git a/Lib/test/exception_hierarchy.txt b/Lib/test/exception_hierarchy.txt
index 73ccb66..5037b33 100644
--- a/Lib/test/exception_hierarchy.txt
+++ b/Lib/test/exception_hierarchy.txt
@@ -47,3 +47,4 @@
+-- ImportWarning
+-- UnicodeWarning
+-- BytesWarning
+ +-- ResourceWarning
diff --git a/Lib/test/test_gc.py b/Lib/test/test_gc.py
index 6c8907d..9de7c29 100644
--- a/Lib/test/test_gc.py
+++ b/Lib/test/test_gc.py
@@ -485,7 +485,7 @@
gc.set_debug(%s)
"""
def run_command(code):
- p = subprocess.Popen([sys.executable, "-c", code],
+ p = subprocess.Popen([sys.executable, "-Wd", "-c", code],
stdout=subprocess.PIPE,
stderr=subprocess.PIPE)
stdout, stderr = p.communicate()
@@ -494,11 +494,13 @@
return strip_python_stderr(stderr)
stderr = run_command(code % "0")
- self.assertIn(b"gc: 2 uncollectable objects at shutdown", stderr)
+ self.assertIn(b"ResourceWarning: gc: 2 uncollectable objects at "
+ b"shutdown; use", stderr)
self.assertNotIn(b"<X 'first'>", stderr)
# With DEBUG_UNCOLLECTABLE, the garbage list gets printed
stderr = run_command(code % "gc.DEBUG_UNCOLLECTABLE")
- self.assertIn(b"gc: 2 uncollectable objects at shutdown", stderr)
+ self.assertIn(b"ResourceWarning: gc: 2 uncollectable objects at "
+ b"shutdown", stderr)
self.assertTrue(
(b"[<X 'first'>, <X 'second'>]" in stderr) or
(b"[<X 'second'>, <X 'first'>]" in stderr), stderr)
diff --git a/Lib/warnings.py b/Lib/warnings.py
index a81aab3..5b5821b 100644
--- a/Lib/warnings.py
+++ b/Lib/warnings.py
@@ -383,4 +383,11 @@
else:
bytes_action = "ignore"
simplefilter(bytes_action, category=BytesWarning, append=1)
+ # resource usage warnings are enabled by default in pydebug mode
+ if hasattr(sys, 'gettotalrefcount'):
+ resource_action = "always"
+ else:
+ resource_action = "ignore"
+ simplefilter(resource_action, category=ResourceWarning, append=1)
+
del _warnings_defaults
diff --git a/Misc/NEWS b/Misc/NEWS
index e1b818d..015ce1f 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -691,7 +691,7 @@
- Issue #8524: Add a detach() method to socket objects, so as to put the socket
into the closed state without closing the underlying file descriptor.
-- Issue #477863: Print a warning at shutdown if gc.garbage is not empty.
+- Issue #477863: Emit a ResourceWarning at shutdown if gc.garbage is not empty.
- Issue #6869: Fix a refcount problem in the _ctypes extension.
diff --git a/Modules/gcmodule.c b/Modules/gcmodule.c
index a95bec7..3f96c42 100644
--- a/Modules/gcmodule.c
+++ b/Modules/gcmodule.c
@@ -1368,11 +1368,16 @@
{
if (!(debug & DEBUG_SAVEALL)
&& garbage != NULL && PyList_GET_SIZE(garbage) > 0) {
- PySys_WriteStderr(
- "gc: "
- "%" PY_FORMAT_SIZE_T "d uncollectable objects at shutdown:\n",
- PyList_GET_SIZE(garbage)
- );
+ char *message;
+ if (debug & DEBUG_UNCOLLECTABLE)
+ message = "gc: %" PY_FORMAT_SIZE_T "d uncollectable objects at " \
+ "shutdown";
+ else
+ message = "gc: %" PY_FORMAT_SIZE_T "d uncollectable objects at " \
+ "shutdown; use gc.set_debug(gc.DEBUG_UNCOLLECTABLE) to list them";
+ if (PyErr_WarnFormat(PyExc_ResourceWarning, 0, message,
+ PyList_GET_SIZE(garbage)) < 0)
+ PyErr_WriteUnraisable(NULL);
if (debug & DEBUG_UNCOLLECTABLE) {
PyObject *repr = NULL, *bytes = NULL;
repr = PyObject_Repr(garbage);
@@ -1387,11 +1392,6 @@
Py_XDECREF(repr);
Py_XDECREF(bytes);
}
- else {
- PySys_WriteStderr(
- " Use gc.set_debug(gc.DEBUG_UNCOLLECTABLE) to list them.\n"
- );
- }
}
}
diff --git a/Objects/exceptions.c b/Objects/exceptions.c
index b82b6ba..5715b26 100644
--- a/Objects/exceptions.c
+++ b/Objects/exceptions.c
@@ -1852,6 +1852,7 @@
"Base class for warnings about Unicode related problems, mostly\n"
"related to conversion problems.");
+
/*
* BytesWarning extends Warning
*/
@@ -1860,6 +1861,13 @@
"related to conversion from str or comparing to str.");
+/*
+ * ResourceWarning extends Warning
+ */
+SimpleExtendsException(PyExc_Warning, ResourceWarning,
+ "Base class for warnings about resource usage.");
+
+
/* Pre-computed MemoryError instance. Best to create this as early as
* possible and not wait until a MemoryError is actually raised!
@@ -1939,6 +1947,7 @@
PRE_INIT(ImportWarning)
PRE_INIT(UnicodeWarning)
PRE_INIT(BytesWarning)
+ PRE_INIT(ResourceWarning)
bltinmod = PyImport_ImportModule("builtins");
if (bltinmod == NULL)
@@ -2001,6 +2010,7 @@
POST_INIT(ImportWarning)
POST_INIT(UnicodeWarning)
POST_INIT(BytesWarning)
+ POST_INIT(ResourceWarning)
PyExc_MemoryErrorInst = BaseException_new(&_PyExc_MemoryError, NULL, NULL);
if (!PyExc_MemoryErrorInst)
diff --git a/Python/_warnings.c b/Python/_warnings.c
index a4e9d48..87755e1 100644
--- a/Python/_warnings.c
+++ b/Python/_warnings.c
@@ -835,6 +835,7 @@
static PyObject *ignore_str = NULL;
static PyObject *error_str = NULL;
static PyObject *default_str = NULL;
+ static PyObject *always_str = NULL;
PyObject *action_obj = NULL;
PyObject *lineno, *result;
@@ -862,6 +863,14 @@
}
action_obj = default_str;
}
+ else if (!strcmp(action, "always")) {
+ if (always_str == NULL) {
+ always_str = PyUnicode_InternFromString("always");
+ if (always_str == NULL)
+ return NULL;
+ }
+ action_obj = always_str;
+ }
else {
Py_FatalError("unknown action");
}
@@ -879,10 +888,10 @@
init_filters(void)
{
/* Don't silence DeprecationWarning if -3 was used. */
- PyObject *filters = PyList_New(4);
+ PyObject *filters = PyList_New(5);
unsigned int pos = 0; /* Post-incremented in each use. */
unsigned int x;
- const char *bytes_action;
+ const char *bytes_action, *resource_action;
if (filters == NULL)
return NULL;
@@ -901,7 +910,14 @@
bytes_action = "ignore";
PyList_SET_ITEM(filters, pos++, create_filter(PyExc_BytesWarning,
bytes_action));
-
+ /* resource usage warnings are enabled by default in pydebug mode */
+#ifdef Py_DEBUG
+ resource_action = "always";
+#else
+ resource_action = "ignore";
+#endif
+ PyList_SET_ITEM(filters, pos++, create_filter(PyExc_ResourceWarning,
+ resource_action));
for (x = 0; x < pos; x += 1) {
if (PyList_GET_ITEM(filters, x) == NULL) {
Py_DECREF(filters);
diff --git a/Python/errors.c b/Python/errors.c
index e3486b9..0490614 100644
--- a/Python/errors.c
+++ b/Python/errors.c
@@ -767,8 +767,10 @@
}
Py_XDECREF(moduleName);
}
- PyFile_WriteString(" in ", f);
- PyFile_WriteObject(obj, f, 0);
+ if (obj) {
+ PyFile_WriteString(" in ", f);
+ PyFile_WriteObject(obj, f, 0);
+ }
PyFile_WriteString(" ignored\n", f);
PyErr_Clear(); /* Just in case */
}