FazBrowse GitHub Viewer | Trending |
URL:
| Home
Tools: [Download Repo ZIP]   [Original HTTPS Page]

bpo-45107: Make LOAD_METHOD_CLASS safer and faster, clean up comments by Fidget-Spinner · Pull Request #28177 · python/cpython · GitHub

/ cpython Public

bpo-45107: Make LOAD_METHOD_CLASS safer and faster, clean up comments #28177

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
Fidget-Spinner merged 6 commits into from
Sep 17, 2021
Conversation 13 Commits 6 Checks 0 Files changed
Merged

bpo-45107: Make LOAD_METHOD_CLASS safer and faster, clean up comments #28177

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
6 commits
Select commit Hold shift + click to select a range
c2a36c4
Remove dict calculation and check
Fidget-Spinner Sep 5, 2021
af0dd27
Improve comments
Fidget-Spinner Sep 5, 2021
9b83ccb
make checks stricter
Fidget-Spinner Sep 15, 2021
82814e9
Check cls is a type, remove dict calculation
Fidget-Spinner Sep 16, 2021
6ae6eff
remove useless assert
Fidget-Spinner Sep 16, 2021
cad0258
Merge remote-tracking branch 'upstream/main' into micro_opt_lm_class
Fidget-Spinner Sep 17, 2021
File filter

Filter by extension

Filter by extension .c  (2) All 1 file type selected
Viewed files
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Unified
Split
Hide whitespace
Diff view
Unified
Split
Hide whitespace
9 changes: 2 additions & 7 deletions Python/ceval.c
Show comments
View file
Open in desktop
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
Show hidden characters
Original file line number Diff line number Diff line change
Expand Up @@ -4496,6 +4496,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, InterpreterFrame *frame, int thr
}

TARGET(LOAD_METHOD_MODULE): {
/* LOAD_METHOD, for module methods */
assert(cframe.use_tracing == 0);
PyObject *owner = TOP();
PyObject *res;
Expand All @@ -4515,15 +4516,9 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, InterpreterFrame *frame, int thr
_PyObjectCache *cache2 = &caches[-2].obj;

PyObject *cls = TOP();
PyTypeObject *cls_type = Py_TYPE(cls);
assert(cls_type->tp_dictoffset > 0);
PyObject *dict = *(PyObject **) ((char *)cls + cls_type->tp_dictoffset);
// Don't care if no dict -- tp_version_tag should catch anything wrong.
DEOPT_IF(dict != NULL && ((PyDictObject *)dict)->ma_keys->dk_version !=
cache1->dk_version_or_hint, LOAD_METHOD);
DEOPT_IF(!PyType_Check(cls), LOAD_METHOD);
DEOPT_IF(((PyTypeObject *)cls)->tp_version_tag != cache1->tp_version,
LOAD_METHOD);
assert(cache1->dk_version_or_hint != 0);
assert(cache1->tp_version != 0);

STAT_INC(LOAD_METHOD, hit);
Expand Down
15 changes: 7 additions & 8 deletions Python/specialize.c
Show comments
View file
Open in desktop
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
Show hidden characters
Original file line number Diff line number Diff line change
Expand Up @@ -974,20 +974,19 @@ _Py_Specialize_LoadMethod(PyObject *owner, _Py_CODEUNIT *instr, PyObject *name,
// Fall through.
} // Else owner is maybe a builtin with no dict, or __slots__. Doesn't matter.

/* `descr` is borrowed. Just check tp_version_tag before accessing in case
* it's deleted. This is safe for methods (even inherited ones from super
* classes!) as long as tp_version_tag is validated for two main reasons:
/* `descr` is borrowed. This is safe for methods (even inherited ones from
* super classes!) as long as tp_version_tag is validated for two main reasons:
*
* 1. The class will always hold a reference to the method so it will
* usually not be GC-ed. Should it be deleted in Python, e.g.
* `del obj.meth`, tp_version_tag will be invalidated, because of reason 2.
*
* 2. The pre-existing type method cache (MCACHE) uses the same principles
* of caching a borrowed descriptor. It does all the heavy lifting for us.
* E.g. it invalidates on any MRO modification, on any type object
* change along said MRO, etc. (see PyType_Modified usages in typeobject.c).
* The type method cache has been working since Python 2.6 and it's
* battle-tested.
* of caching a borrowed descriptor. The MCACHE infrastructure does all the
* heavy lifting for us. E.g. it invalidates tp_version_tag on any MRO
* modification, on any type object change along said MRO, etc. (see
* PyType_Modified usages in typeobject.c). The MCACHE has been
* working since Python 2.6 and it's battle-tested.
*/
cache2->obj = descr;
cache1->dk_version_or_hint = keys_version;
Expand Down
Back | FazBrowse Home | New Git URL