[pull] main from python:main

Doc/about.rst

@@ -10,7 +10,7 @@ and now maintained as an independent project.
 .. _reStructuredText: https://docutils.sourceforge.io/rst.html
 .. _Sphinx: https://www.sphinx-doc.org/
 
-.. In the online version of these documents, you can submit comments and suggest
+.. In the online version of this documentation, you can submit comments and suggest
    changes directly on the documentation pages.
 
 Development of the documentation and its toolchain is an entirely volunteer

Doc/c-api/import.rst

@@ -146,7 +146,7 @@ Importing Modules
       alternatives.
 
    .. versionchanged:: 3.15
-      ``__cached__`` is no longer set.
+      The ``__cached__`` attribute is no longer set.
 
 
 .. c:function:: PyObject* PyImport_ExecCodeModuleEx(const char *name, PyObject *co, const char *pathname)
@@ -170,7 +170,7 @@ Importing Modules
       :class:`~importlib.machinery.ModuleSpec` for alternatives.
 
    .. versionchanged:: 3.15
-      ``__cached__`` no longer set.
+      The ``__cached__`` attribute no longer set.
 
 
 .. c:function:: PyObject* PyImport_ExecCodeModuleWithPathnames(const char *name, PyObject *co, const char *pathname, const char *cpathname)

Doc/library/runpy.rst

@@ -97,7 +97,7 @@ The :mod:`!runpy` module provides two functions:
       :class:`~importlib.machinery.ModuleSpec` for alternatives.
 
    .. versionchanged:: 3.15
-      ``__cached__`` is no longer set.
+      The global variable ``__cached__`` is no longer set.
 
 .. function:: run_path(path_name, init_globals=None, run_name=None)
 
@@ -175,7 +175,7 @@ The :mod:`!runpy` module provides two functions:
       ``__package__`` are deprecated.
 
    .. versionchanged:: 3.15
-      ``__cached__`` is no longer set.
+      The global variable ``__cached__`` is no longer set.
 
 .. seealso::
 

Doc/reference/datamodel.rst

@@ -1099,14 +1099,9 @@ this approach.
    :ref:`import system <importsystem>` may opt to leave it unset if it
    has no semantic meaning (for example, a module loaded from a database).
 
-   .. deprecated-removed:: 3.13 3.15
-      Setting ``__cached__`` on a module while failing to set
-      :attr:`!__spec__.cached` is deprecated. In Python 3.15,
-      ``__cached__`` will cease to be set or taken into consideration by
-      the import system or standard library.
-
-   .. versionchanged:: 3.15
-      ``__cached__`` is no longer set.
+.. versionchanged:: 3.15
+   The ``__cached__`` attribute is no longer set on modules or taken into
+   consideration by the import system or standard library.
 
 Other writable attributes on module objects
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Doc/tools/templates/indexsidebar.html

@@ -1,5 +1,5 @@
 <h3>{% trans %}Download{% endtrans %}</h3>
-<p><a href="{{ pathto('download') }}">{% trans %}Download these documents{% endtrans %}</a></p>
+<p><a href="{{ pathto('download') }}">{% trans %}Download the documentation{% endtrans %}</a></p>
 <h3>{% trans %}Docs by version{% endtrans %}</h3>
 <ul>
   {# _docs_by_version.html is overwritten by build_docs.py for non-EOL versions #}

Doc/whatsnew/3.15.rst

@@ -880,6 +880,14 @@ Other language changes
   other, as regular dynamic extensions do.
   (Contributed by Stefano Rivera in :gh:`122931`.)
 
+* The ``__cached__`` attribute on modules, which was deprecated since version
+  3.13, is no longer set or taken into consideration by the import system or
+  standard library.
+  Use :attr:`__spec__.cached <importlib.machinery.ModuleSpec.cached>` instead.
+  (Contributed by Brett Cannon in :gh:`97879`)
+
+  Note that the :attr:`~module.__loader__` and :attr:`~module.__package__`
+  attributes are also deprecated and scheduled for removal.
 
 
 Default interactive shell

Lib/test/test_free_threading/test_gc.py

@@ -2,6 +2,7 @@
 
 import threading
 from threading import Thread
+import time
 from unittest import TestCase
 import gc
 
@@ -94,6 +95,26 @@ def evil():
         thread.start()
         thread.join()
 
+    def test_gc_callbacks_race_with_mutation(self):
+        def collect():
+            b.wait()
+            while not stop.is_set():
+                gc.collect()
+
+        def mutate():
+            b.wait()
+            while not stop.is_set():
+                gc.callbacks[:] = [lambda *_: _ for _ in range(16)]
+                time.sleep(0)
+                gc.callbacks.clear()
+
+        threads = [threading.Thread(target=f) for f in (collect, mutate) * 4]
+        b = threading.Barrier(len(threads) + 1)
+        stop = threading.Event()
+
+        with threading_helper.start_threads(threads, stop.set):
+            b.wait()
+            time.sleep(0.2)
     def test_set_threshold(self):
         # GH-148613: Setting the GC threshold from another thread could cause a
         # race between the `gc_should_collect` and `gc_set_threshold` functions.

Misc/NEWS.d/next/Core_and_Builtins/2026-05-18-12-32-33.gh-issue-149816.v18Ypf.rst

@@ -0,0 +1,2 @@
+Fix race conditions in ``invoke_gc_callback`` iterating ``gc.callbacks``
+in free-threading mode.

Python/gc_free_threading.c

@@ -9,6 +9,7 @@
 #include "pycore_initconfig.h"    // _PyStatus_NO_MEMORY()
 #include "pycore_interp.h"        // PyInterpreterState.gc
 #include "pycore_interpframe.h"   // _PyFrame_GetLocalsArray()
+#include "pycore_list.h"          // _PyList_GetItemRef()
 #include "pycore_object_alloc.h"  // _PyObject_MallocWithType()
 #include "pycore_pystate.h"       // _PyThreadState_GET()
 #include "pycore_tstate.h"        // _PyThreadStateImpl
@@ -1940,33 +1941,36 @@ invoke_gc_callback(PyThreadState *tstate, const char *phase,
 
     /* The local variable cannot be rebound, check it for sanity */
     assert(PyList_CheckExact(gcstate->callbacks));
-    PyObject *info = NULL;
-    if (PyList_GET_SIZE(gcstate->callbacks) != 0) {
-        info = Py_BuildValue("{sisnsnsnsd}",
-            "generation", generation,
-            "collected", collected,
-            "uncollectable", uncollectable,
-            "candidates", candidates,
-            "duration", duration);
-        if (info == NULL) {
-            PyErr_FormatUnraisable("Exception ignored while "
-                                   "invoking gc callbacks");
-            return;
-        }
+    if (PyList_GET_SIZE(gcstate->callbacks) == 0) {
+        return;
+    }
+
+    PyObject *info = Py_BuildValue("{sisnsnsnsd}",
+        "generation", generation,
+        "collected", collected,
+        "uncollectable", uncollectable,
+        "candidates", candidates,
+        "duration", duration);
+    if (info == NULL) {
+        PyErr_FormatUnraisable("Exception ignored while "
+                               "invoking gc callbacks");
+        return;
     }
 
     PyObject *phase_obj = PyUnicode_FromString(phase);
     if (phase_obj == NULL) {
-        Py_XDECREF(info);
+        Py_DECREF(info);
         PyErr_FormatUnraisable("Exception ignored while "
                                "invoking gc callbacks");
         return;
     }
 
     PyObject *stack[] = {phase_obj, info};
     for (Py_ssize_t i=0; i<PyList_GET_SIZE(gcstate->callbacks); i++) {
-        PyObject *r, *cb = PyList_GET_ITEM(gcstate->callbacks, i);
-        Py_INCREF(cb); /* make sure cb doesn't go away */
+        PyObject *r, *cb = _PyList_GetItemRef((PyListObject *)gcstate->callbacks, i);
+        if (cb == NULL) {
+            break;
+        }
         r = PyObject_Vectorcall(cb, stack, 2, NULL);
         if (r == NULL) {
             PyErr_FormatUnraisable("Exception ignored while "
@@ -1978,7 +1982,7 @@ invoke_gc_callback(PyThreadState *tstate, const char *phase,
         Py_DECREF(cb);
     }
     Py_DECREF(phase_obj);
-    Py_XDECREF(info);
+    Py_DECREF(info);
     assert(!_PyErr_Occurred(tstate));
 }