Revert "bpo-31356: Add context manager to temporarily disable GC GH-5495 (#5496)
This reverts commit 72a0d218dcc94a3cc409a9ef32dfcd5a7bbcb43c.
The reverted commit had a few issues so it was unanimously decided
to undo it. See the bpo issue for details.
(cherry picked from commit 383b32fe108ea627699cc9c644fba5f8bae95d73)
Co-authored-by: Yury Selivanov <yury@magic.io>
diff --git a/Doc/library/gc.rst b/Doc/library/gc.rst
index 92240c7..153d8fb 100644
--- a/Doc/library/gc.rst
+++ b/Doc/library/gc.rst
@@ -33,34 +33,6 @@
Disable automatic garbage collection.
-.. class:: ensure_disabled()
-
- Return a context manager object that disables the garbage collector and reenables the previous
- state upon completion of the block. This is basically equivalent to::
-
- from gc import enable, disable, isenabled
-
- @contextmanager
- def ensure_disabled():
- was_enabled_previously = isenabled()
- gc.disable()
- yield
- if was_enabled_previously:
- gc.enable()
-
- And lets you write code like this::
-
- with ensure_disabled():
- run_some_timing()
-
- with ensure_disabled():
- # do_something_that_has_real_time_guarantees
- # such as a pair trade, robotic braking, etc
-
- without needing to explicitly enable and disable the garbage collector yourself.
- This context manager is implemented in C to assure atomicity, thread safety and speed.
-
-
.. function:: isenabled()
Returns true if automatic collection is enabled.
diff --git a/Include/internal/mem.h b/Include/internal/mem.h
index 4a84b4a..a731e30 100644
--- a/Include/internal/mem.h
+++ b/Include/internal/mem.h
@@ -116,7 +116,6 @@
int enabled;
int debug;
- long disabled_threads;
/* linked lists of container objects */
struct gc_generation generations[NUM_GENERATIONS];
PyGC_Head *generation0;
diff --git a/Lib/test/test_gc.py b/Lib/test/test_gc.py
index 246980a..904fc7d 100644
--- a/Lib/test/test_gc.py
+++ b/Lib/test/test_gc.py
@@ -1,7 +1,7 @@
import unittest
from test.support import (verbose, refcount_test, run_unittest,
strip_python_stderr, cpython_only, start_threads,
- temp_dir, requires_type_collecting,reap_threads)
+ temp_dir, requires_type_collecting)
from test.support.script_helper import assert_python_ok, make_script
import sys
@@ -9,8 +9,6 @@
import gc
import weakref
import threading
-import warnings
-
try:
from _testcapi import with_tp_del
@@ -1009,73 +1007,6 @@
# empty __dict__.
self.assertEqual(x, None)
- def test_ensure_disabled(self):
- original_status = gc.isenabled()
-
- with gc.ensure_disabled():
- inside_status = gc.isenabled()
-
- after_status = gc.isenabled()
- self.assertEqual(original_status, True)
- self.assertEqual(inside_status, False)
- self.assertEqual(after_status, True)
-
- def test_ensure_disabled_with_gc_disabled(self):
- gc.disable()
-
- original_status = gc.isenabled()
-
- with gc.ensure_disabled():
- inside_status = gc.isenabled()
-
- after_status = gc.isenabled()
- self.assertEqual(original_status, False)
- self.assertEqual(inside_status, False)
- self.assertEqual(after_status, False)
-
- @reap_threads
- def test_ensure_disabled_thread(self):
-
- thread_original_status = None
- thread_inside_status = None
- thread_after_status = None
-
- def disabling_thread():
- nonlocal thread_original_status
- nonlocal thread_inside_status
- nonlocal thread_after_status
- thread_original_status = gc.isenabled()
-
- with gc.ensure_disabled():
- time.sleep(0.01)
- thread_inside_status = gc.isenabled()
-
- thread_after_status = gc.isenabled()
-
- original_status = gc.isenabled()
-
- with warnings.catch_warnings(record=True) as w, gc.ensure_disabled():
- inside_status_before_thread = gc.isenabled()
- thread = threading.Thread(target=disabling_thread)
- thread.start()
- inside_status_after_thread = gc.isenabled()
-
- after_status = gc.isenabled()
- thread.join()
-
- self.assertEqual(len(w), 1)
- self.assertTrue(issubclass(w[-1].category, RuntimeWarning))
- self.assertEqual("Garbage collector enabled while another thread is "
- "inside gc.ensure_enabled", str(w[-1].message))
- self.assertEqual(original_status, True)
- self.assertEqual(inside_status_before_thread, False)
- self.assertEqual(thread_original_status, False)
- self.assertEqual(thread_inside_status, True)
- self.assertEqual(thread_after_status, False)
- self.assertEqual(inside_status_after_thread, False)
- self.assertEqual(after_status, True)
-
-
def test_main():
enabled = gc.isenabled()
gc.disable()
diff --git a/Misc/NEWS.d/3.7.0b1.rst b/Misc/NEWS.d/3.7.0b1.rst
index 4f7bfee..bd3a611 100644
--- a/Misc/NEWS.d/3.7.0b1.rst
+++ b/Misc/NEWS.d/3.7.0b1.rst
@@ -196,17 +196,6 @@
..
-.. bpo: 31356
-.. date: 2017-11-02-00-34-42
-.. nonce: 54Lb8U
-.. section: Core and Builtins
-
-Add a new contextmanager to the gc module that temporarily disables the GC
-and restores the previous state. The implementation is done in C to assure
-atomicity and speed.
-
-..
-
.. bpo: 31179
.. date: 2017-08-10-17-32-48
.. nonce: XcgLYI
diff --git a/Misc/NEWS.d/next/Core and Builtins/2018-02-02-08-50-46.bpo-31356.MNwUOQ.rst b/Misc/NEWS.d/next/Core and Builtins/2018-02-02-08-50-46.bpo-31356.MNwUOQ.rst
new file mode 100644
index 0000000..5022a13
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2018-02-02-08-50-46.bpo-31356.MNwUOQ.rst
@@ -0,0 +1,2 @@
+Remove the new API added in bpo-31356 (gc.ensure_disabled() context
+manager).
diff --git a/Modules/gcmodule.c b/Modules/gcmodule.c
index c057d25..8ba1093 100644
--- a/Modules/gcmodule.c
+++ b/Modules/gcmodule.c
@@ -1067,10 +1067,6 @@
gc_enable_impl(PyObject *module)
/*[clinic end generated code: output=45a427e9dce9155c input=81ac4940ca579707]*/
{
- if(_PyRuntime.gc.disabled_threads){
- PyErr_WarnEx(PyExc_RuntimeWarning, "Garbage collector enabled while another "
- "thread is inside gc.ensure_enabled",1);
- }
_PyRuntime.gc.enabled = 1;
Py_RETURN_NONE;
}
@@ -1512,102 +1508,6 @@
{NULL, NULL} /* Sentinel */
};
-typedef struct {
- PyObject_HEAD
- int previous_gc_state;
-} ensure_disabled_object;
-
-
-static void
-ensure_disabled_object_dealloc(ensure_disabled_object *m_obj)
-{
- Py_TYPE(m_obj)->tp_free((PyObject*)m_obj);
-}
-
-static PyObject *
-ensure_disabled__enter__method(ensure_disabled_object *self, PyObject *args)
-{
- PyGILState_STATE gstate = PyGILState_Ensure();
- ++_PyRuntime.gc.disabled_threads;
- self->previous_gc_state = _PyRuntime.gc.enabled;
- gc_disable_impl(NULL);
- PyGILState_Release(gstate);
- Py_RETURN_NONE;
-}
-
-static PyObject *
-ensure_disabled__exit__method(ensure_disabled_object *self, PyObject *args)
-{
- PyGILState_STATE gstate = PyGILState_Ensure();
- --_PyRuntime.gc.disabled_threads;
- if(self->previous_gc_state){
- gc_enable_impl(NULL);
- }else{
- gc_disable_impl(NULL);
- }
- PyGILState_Release(gstate);
- Py_RETURN_NONE;
-}
-
-
-
-static struct PyMethodDef ensure_disabled_object_methods[] = {
- {"__enter__", (PyCFunction) ensure_disabled__enter__method, METH_NOARGS},
- {"__exit__", (PyCFunction) ensure_disabled__exit__method, METH_VARARGS},
- {NULL, NULL} /* sentinel */
-};
-
-static PyObject *
-new_disabled_obj(PyTypeObject *type, PyObject *args, PyObject *kwdict){
- ensure_disabled_object *self;
- self = (ensure_disabled_object *)type->tp_alloc(type, 0);
- return (PyObject *) self;
-};
-
-static PyTypeObject gc_ensure_disabled_type = {
- PyVarObject_HEAD_INIT(NULL, 0)
- "gc.ensure_disabled", /* tp_name */
- sizeof(ensure_disabled_object), /* tp_size */
- 0, /* tp_itemsize */
- /* methods */
- (destructor) ensure_disabled_object_dealloc,/* tp_dealloc */
- 0, /* tp_print */
- 0, /* tp_getattr */
- 0, /* tp_setattr */
- 0, /* tp_reserved */
- 0, /* tp_repr */
- 0, /* tp_as_number */
- 0, /*tp_as_sequence*/
- 0, /*tp_as_mapping*/
- 0, /*tp_hash*/
- 0, /*tp_call*/
- 0, /*tp_str*/
- PyObject_GenericGetAttr, /*tp_getattro*/
- 0, /*tp_setattro*/
- 0, /*tp_as_buffer*/
- Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /*tp_flags*/
- 0, /*tp_doc*/
- 0, /* tp_traverse */
- 0, /* tp_clear */
- 0, /* tp_richcompare */
- 0, /* tp_weaklistoffset */
- 0, /* tp_iter */
- 0, /* tp_iternext */
- ensure_disabled_object_methods, /* tp_methods */
- 0, /* tp_members */
- 0, /* tp_getset */
- 0, /* tp_base */
- 0, /* tp_dict */
- 0, /* tp_descr_get */
- 0, /* tp_descr_set */
- 0, /* tp_dictoffset */
- 0, /* tp_init */
- PyType_GenericAlloc, /* tp_alloc */
- new_disabled_obj, /* tp_new */
- PyObject_Del, /* tp_free */
-};
-
-
static struct PyModuleDef gcmodule = {
PyModuleDef_HEAD_INIT,
"gc", /* m_name */
@@ -1648,12 +1548,6 @@
if (PyModule_AddObject(m, "callbacks", _PyRuntime.gc.callbacks) < 0)
return NULL;
- if (PyType_Ready(&gc_ensure_disabled_type) < 0)
- return NULL;
- if (PyModule_AddObject(m, "ensure_disabled", (PyObject*) &gc_ensure_disabled_type) < 0)
- return NULL;
-
-
#define ADD_INT(NAME) if (PyModule_AddIntConstant(m, #NAME, NAME) < 0) return NULL
ADD_INT(DEBUG_STATS);
ADD_INT(DEBUG_COLLECTABLE);