Merge branch 'main' into fix-shutil-recursion-loop

Author: ChuheLin

Doc/howto/free-threading-python.rst

@@ -11,9 +11,7 @@ available processing power by running threads in parallel on available CPU cores
 While not all software will benefit from this automatically, programs
 designed with threading in mind will run faster on multi-core hardware.
 
-The free-threaded mode is working and continues to be improved, but
-there is some additional overhead in single-threaded workloads compared
-to the regular build. Additionally, third-party packages, in particular ones
+Some third-party packages, in particular ones
 with an :term:`extension module`, may not be ready for use in a
 free-threaded build, and will re-enable the :term:`GIL`.
 
@@ -101,63 +99,42 @@ This section describes known limitations of the free-threaded CPython build.
 Immortalization
 ---------------
 
-The free-threaded build of the 3.13 release makes some objects :term:`immortal`.
+In the free-threaded build, some objects are :term:`immortal`.
 Immortal objects are not deallocated and have reference counts that are
 never modified.  This is done to avoid reference count contention that would
 prevent efficient multi-threaded scaling.
 
-An object will be made immortal when a new thread is started for the first time
-after the main thread is running.  The following objects are immortalized:
+As of the 3.14 release, immortalization is limited to:
 
-* :ref:`function <user-defined-funcs>` objects declared at the module level
-* :ref:`method <instance-methods>` descriptors
-* :ref:`code <code-objects>` objects
-* :term:`module` objects and their dictionaries
-* :ref:`classes <classes>` (type objects)
-
-Because immortal objects are never deallocated, applications that create many
-objects of these types may see increased memory usage under Python 3.13.  This
-has been addressed in the 3.14 release, where the aforementioned objects use
-deferred reference counting to avoid reference count contention.
-
-Additionally, numeric and string literals in the code as well as strings
-returned by :func:`sys.intern` are also immortalized in the 3.13 release.  This
-behavior is part of the 3.14 release as well and it is expected to remain in
-future free-threaded builds.
+* Code constants: numeric literals, string literals, and tuple literals
+  composed of other constants.
+* Strings interned by :func:`sys.intern`.
 
 
 Frame objects
 -------------
 
-It is not safe to access :ref:`frame <frame-objects>` objects from other
-threads and doing so may cause your program to crash .  This means that
-:func:`sys._current_frames` is generally not safe to use in a free-threaded
-build.  Functions like :func:`inspect.currentframe` and :func:`sys._getframe`
-are generally safe as long as the resulting frame object is not passed to
-another thread.
+It is not safe to access :attr:`frame.f_locals` from a :ref:`frame <frame-objects>`
+object if that frame is currently executing in another thread, and doing so may
+crash the interpreter.
+
 
 Iterators
 ---------
 
-Sharing the same iterator object between multiple threads is generally not
-safe and threads may see duplicate or missing elements when iterating or crash
-the interpreter.
+It is generally not thread-safe to access the same iterator object from
+multiple threads concurrently, and threads may see duplicate or missing
+elements.
 
 
 Single-threaded performance
 ---------------------------
 
 The free-threaded build has additional overhead when executing Python code
-compared to the default GIL-enabled build.  In 3.13, this overhead is about
-40% on the `pyperformance <https://pyperformance.readthedocs.io/>`_ suite.
-Programs that spend most of their time in C extensions or I/O will see
-less of an impact.  The largest impact is because the specializing adaptive
-interpreter (:pep:`659`) is disabled in the free-threaded build.
-
-The specializing adaptive interpreter has been re-enabled in a thread-safe way
-in the 3.14 release.  The performance penalty on single-threaded code in
-free-threaded mode is now roughly 5-10%, depending on the platform and C
-compiler used.
+compared to the default GIL-enabled build.  The amount of overhead depends
+on the workload and hardware.  On the pyperformance benchmark suite, the
+average overhead ranges from about 1% on macOS aarch64 to 8% on x86-64 Linux
+systems.
 
 
 Behavioral changes

Doc/library/select.rst

@@ -115,7 +115,7 @@ The module defines the following:
    :ref:`kevent-objects` below for the methods supported by kevent objects.
 
 
-.. function:: select(rlist, wlist, xlist[, timeout])
+.. function:: select(rlist, wlist, xlist, timeout=None)
 
    This is a straightforward interface to the Unix :c:func:`!select` system call.
    The first three arguments are iterables of 'waitable objects': either
@@ -131,7 +131,7 @@ The module defines the following:
    platform-dependent. (It is known to work on Unix but not on Windows.)  The
    optional *timeout* argument specifies a time-out in seconds; it may be
    a non-integer to specify fractions of seconds.
-   When the *timeout* argument is omitted the function blocks until
+   When the *timeout* argument is omitted or ``None``, the function blocks until
    at least one file descriptor is ready.  A time-out value of zero specifies a
    poll and never blocks.
 

Include/pyport.h

@@ -509,9 +509,15 @@ extern "C" {
 #  define Py_CAN_START_THREADS 1
 #endif
 
-#ifdef WITH_THREAD
-// HAVE_THREAD_LOCAL is just defined here for compatibility's sake
+
+/* gh-142163: Some libraries rely on HAVE_THREAD_LOCAL being undefined, so
+ * we can only define it only when Py_BUILD_CORE is set.*/
+#ifdef Py_BUILD_CORE
+// This is no longer coupled to _Py_thread_local.
 #  define HAVE_THREAD_LOCAL 1
+#endif
+
+#ifdef WITH_THREAD
 #  ifdef thread_local
 #    define _Py_thread_local thread_local
 #  elif __STDC_VERSION__ >= 201112L && !defined(__STDC_NO_THREADS__)

Lib/pdb.py

@@ -130,7 +130,7 @@ def find_first_executable_line(code):
     return code.co_firstlineno
 
 def find_function(funcname, filename):
-    cre = re.compile(r'def\s+%s(\s*\[.+\])?\s*[(]' % re.escape(funcname))
+    cre = re.compile(r'(?:async\s+)?def\s+%s(\s*\[.+\])?\s*[(]' % re.escape(funcname))
     try:
         fp = tokenize.open(filename)
     except OSError:
@@ -1487,7 +1487,9 @@ def lineinfo(self, identifier):
             f = self.lookupmodule(parts[0])
             if f:
                 fname = f
-            item = parts[1]
+                item = parts[1]
+            else:
+                return failed
         answer = find_function(item, self.canonic(fname))
         return answer or failed
 

Lib/test/test_pdb.py

@@ -4587,6 +4587,41 @@ def bar():
             ]))
             self.assertIn('break in bar', stdout)
 
+    @unittest.skipIf(SKIP_CORO_TESTS, "Coroutine tests are skipped")
+    def test_async_break(self):
+        script = """
+            import asyncio
+
+            async def main():
+                pass
+
+            asyncio.run(main())
+        """
+        commands = """
+            break main
+            continue
+            quit
+        """
+        stdout, stderr = self.run_pdb_script(script, commands)
+        self.assertRegex(stdout, r"Breakpoint 1 at .*main\.py:5")
+        self.assertIn("pass", stdout)
+
+    def test_issue_59000(self):
+        script = """
+            def foo():
+                pass
+
+            class C:
+                def foo(self):
+                    pass
+        """
+        commands = """
+            break C.foo
+            quit
+        """
+        stdout, stderr = self.run_pdb_script(script, commands)
+        self.assertIn("The specified object 'C.foo' is not a function", stdout)
+
 
 class ChecklineTests(unittest.TestCase):
     def setUp(self):

Misc/NEWS.d/next/C_API/2025-12-01-18-17-16.gh-issue-142163.2HiX5A.rst

@@ -0,0 +1,2 @@
+Fix the ``HAVE_THREAD_LOCAL`` macro being defined without the
+``Py_BUILD_CORE`` macro set after including :file:`Python.h`.

Misc/NEWS.d/next/Library/2025-11-25-16-00-29.gh-issue-59000.YtOyJy.rst

@@ -0,0 +1 @@
+Fix :mod:`pdb` breakpoint resolution for class methods when the module defining the class is not imported.

Misc/NEWS.d/next/Library/2025-11-30-04-28-30.gh-issue-141982.pxZct9.rst

@@ -0,0 +1 @@
+Allow :mod:`pdb` to set breakpoints on async functions with function names.