Merge branch 'main' into astdeep

.github/CODEOWNERS

@@ -13,6 +13,8 @@
 
 # Build system
 configure*                    @erlend-aasland @corona10
+Makefile.pre.in               @erlend-aasland
+Modules/Setup*                @erlend-aasland
 
 # asyncio
 **/*asyncio*                  @1st1 @asvetlov @gvanrossum @kumaraditya303 @willingc
@@ -40,7 +42,7 @@ Python/bytecodes.c            @markshannon
 Python/optimizer*.c           @markshannon
 Python/optimizer_analysis.c   @Fidget-Spinner
 Python/optimizer_bytecodes.c  @Fidget-Spinner
-Python/symtable.c             @JelleZijlstra @carljm 
+Python/symtable.c             @JelleZijlstra @carljm
 Lib/_pyrepl/*                 @pablogsal @lysnikolaou @ambv
 Lib/test/test_patma.py        @brandtbucher
 Lib/test/test_type_*.py       @JelleZijlstra
@@ -199,7 +201,6 @@ Doc/c-api/stable.rst          @encukou
 **/*itertools*                @rhettinger
 **/*collections*              @rhettinger
 **/*random*                   @rhettinger
-**/*queue*                    @rhettinger
 **/*bisect*                   @rhettinger
 **/*heapq*                    @rhettinger
 **/*functools*                @rhettinger
@@ -210,6 +211,7 @@ Doc/c-api/stable.rst          @encukou
 **/*ensurepip*                @pfmoore @pradyunsg
 
 **/*idlelib*                  @terryjreedy
+/Doc/library/idle.rst         @terryjreedy
 
 **/*typing*                   @JelleZijlstra @AlexWaygood
 

.github/workflows/build.yml

@@ -54,7 +54,7 @@ jobs:
             # into the PR branch anyway.
             #
             # https://github.com/python/core-workflow/issues/373
-            git diff --name-only origin/$GITHUB_BASE_REF.. | grep -qvE '(\.rst$|^Doc|^Misc|^\.pre-commit-config\.yaml$|\.ruff\.toml$)' && echo "run_tests=true" >> $GITHUB_OUTPUT || true
+            git diff --name-only origin/$GITHUB_BASE_REF.. | grep -qvE '(\.rst$|^Doc|^Misc|^\.pre-commit-config\.yaml$|\.ruff\.toml$|\.md$|mypy\.ini$)' && echo "run_tests=true" >> $GITHUB_OUTPUT || true
           fi
 
           # Check if we should run hypothesis tests

.github/workflows/jit.yml

@@ -133,17 +133,15 @@ jobs:
           make all --jobs 4
           ./python.exe -m test --multiprocess 0 --timeout 4500 --verbose2 --verbose3
 
-      # --with-lto has been removed temporarily as a result of an open issue in LLVM 18 (see https://github.com/llvm/llvm-project/issues/87553)
       - name: Native Linux
         if: runner.os == 'Linux' && matrix.architecture == 'x86_64'
         run: |
           sudo bash -c "$(wget -O - https://apt.llvm.org/llvm.sh)" ./llvm.sh ${{ matrix.llvm }}
           export PATH="$(llvm-config-${{ matrix.llvm }} --bindir):$PATH"
-          ./configure --enable-experimental-jit ${{ matrix.debug && '--with-pydebug' || '--enable-optimizations' }}
+          ./configure --enable-experimental-jit ${{ matrix.debug && '--with-pydebug' || '--enable-optimizations --with-lto' }}
           make all --jobs 4
           ./python -m test --multiprocess 0 --timeout 4500 --verbose2 --verbose3
 
-      # --with-lto has been removed temporarily as a result of an open issue in LLVM 18 (see https://github.com/llvm/llvm-project/issues/87553)
       - name: Emulated Linux
         if: runner.os == 'Linux' && matrix.architecture != 'x86_64'
         # The --ignorefile on ./python -m test is used to exclude tests known to fail when running on an emulated Linux.
@@ -161,7 +159,7 @@ jobs:
           CC="${{ matrix.compiler == 'clang' && 'clang --target=$HOST' || '$HOST-gcc' }}" \
             CPP="$CC --preprocess" \
             HOSTRUNNER=qemu-${{ matrix.architecture }} \
-            ./configure --enable-experimental-jit ${{ matrix.debug && '--with-pydebug' || '--enable-optimizations ' }} --build=x86_64-linux-gnu --host="$HOST" --with-build-python=../build/bin/python3 --with-pkg-config=no ac_cv_buggy_getaddrinfo=no ac_cv_file__dev_ptc=no ac_cv_file__dev_ptmx=yes
+            ./configure --enable-experimental-jit ${{ matrix.debug && '--with-pydebug' || '--enable-optimizations --with-lto' }} --build=x86_64-linux-gnu --host="$HOST" --with-build-python=../build/bin/python3 --with-pkg-config=no ac_cv_buggy_getaddrinfo=no ac_cv_file__dev_ptc=no ac_cv_file__dev_ptmx=yes
           make all --jobs 4
           ./python -m test --ignorefile=Tools/jit/ignore-tests-emulated-linux.txt --multiprocess 0 --timeout 4500 --verbose2 --verbose3
 

.readthedocs.yml

@@ -26,6 +26,9 @@ build:
         exit 183;
       fi
 
+    - asdf plugin add uv
+    - asdf install uv latest
+    - asdf global uv latest
     - make -C Doc venv html
     - mkdir _readthedocs
     - mv Doc/build/html _readthedocs/html

Doc/Makefile

@@ -152,7 +152,7 @@ htmlview: html
 
 .PHONY: ensure-sphinx-autobuild
 ensure-sphinx-autobuild: venv
-	$(VENVDIR)/bin/sphinx-autobuild --version > /dev/null || $(VENVDIR)/bin/python3 -m pip install sphinx-autobuild
+	$(call ensure_package,sphinx-autobuild)
 
 .PHONY: htmllive
 htmllive: SPHINXBUILD = $(VENVDIR)/bin/sphinx-autobuild
@@ -174,10 +174,15 @@ venv:
 		echo "To recreate it, remove it first with \`make clean-venv'."; \
 	else \
 		echo "Creating venv in $(VENVDIR)"; \
-		$(PYTHON) -m venv $(VENVDIR); \
-		$(VENVDIR)/bin/python3 -m pip install --upgrade pip; \
-		$(VENVDIR)/bin/python3 -m pip install -r $(REQUIREMENTS); \
-		echo "The venv has been created in the $(VENVDIR) directory"; \
+		if uv --version > /dev/null; then \
+			uv venv $(VENVDIR); \
+			VIRTUAL_ENV=$(VENVDIR) uv pip install -r $(REQUIREMENTS); \
+		else \
+			$(PYTHON) -m venv $(VENVDIR); \
+			$(VENVDIR)/bin/python3 -m pip install --upgrade pip; \
+			$(VENVDIR)/bin/python3 -m pip install -r $(REQUIREMENTS); \
+			echo "The venv has been created in the $(VENVDIR) directory"; \
+		fi; \
 	fi
 
 .PHONY: dist
@@ -235,9 +240,17 @@ dist:
 	rm -r dist/python-$(DISTVERSION)-docs-texinfo
 	rm dist/python-$(DISTVERSION)-docs-texinfo.tar
 
+define ensure_package
+	if uv --version > /dev/null; then \
+		$(VENVDIR)/bin/python3 -m $(1) --version > /dev/null || VIRTUAL_ENV=$(VENVDIR) uv pip install $(1); \
+	else \
+		$(VENVDIR)/bin/python3 -m $(1) --version > /dev/null || $(VENVDIR)/bin/python3 -m pip install $(1); \
+	fi
+endef
+
 .PHONY: check
 check: venv
-	$(VENVDIR)/bin/python3 -m pre_commit --version > /dev/null || $(VENVDIR)/bin/python3 -m pip install pre-commit
+	$(call ensure_package,pre_commit)
 	$(VENVDIR)/bin/python3 -m pre_commit run --all-files
 
 .PHONY: serve

Doc/README.rst

@@ -28,7 +28,7 @@ install the tools into there.
 Using make
 ----------
 
-To get started on UNIX, you can create a virtual environment and build
+To get started on Unix, you can create a virtual environment and build
 documentation with the commands::
 
   make venv
@@ -40,13 +40,13 @@ If you'd like to create the virtual environment in a different location,
 you can specify it using the ``VENVDIR`` variable.
 
 You can also skip creating the virtual environment altogether, in which case
-the Makefile will look for instances of ``sphinx-build`` and ``blurb``
+the ``Makefile`` will look for instances of ``sphinx-build`` and ``blurb``
 installed on your process ``PATH`` (configurable with the ``SPHINXBUILD`` and
 ``BLURB`` variables).
 
-On Windows, we try to emulate the Makefile as closely as possible with a
+On Windows, we try to emulate the ``Makefile`` as closely as possible with a
 ``make.bat`` file. If you need to specify the Python interpreter to use,
-set the PYTHON environment variable.
+set the ``PYTHON`` environment variable.
 
 Available make targets are:
 
@@ -62,15 +62,19 @@ Available make targets are:
 * "htmlview", which re-uses the "html" builder, but then opens the main page
   in your default web browser.
 
+* "htmllive", which re-uses the "html" builder, rebuilds the docs,
+  starts a local server, and automatically reloads the page in your browser
+  when you make changes to reST files (Unix only).
+
 * "htmlhelp", which builds HTML files and a HTML Help project file usable to
   convert them into a single Compiled HTML (.chm) file -- these are popular
   under Microsoft Windows, but very handy on every platform.
 
   To create the CHM file, you need to run the Microsoft HTML Help Workshop
-  over the generated project (.hhp) file.  The make.bat script does this for
+  over the generated project (.hhp) file.  The ``make.bat`` script does this for
   you on Windows.
 
-* "latex", which builds LaTeX source files as input to "pdflatex" to produce
+* "latex", which builds LaTeX source files as input to ``pdflatex`` to produce
   PDF documents.
 
 * "text", which builds a plain text file for each source file.
@@ -95,8 +99,6 @@ Available make targets are:
 
 * "check", which checks for frequent markup errors.
 
-* "serve", which serves the build/html directory on port 8000.
-
 * "dist", (Unix only) which creates distributable archives of HTML, text,
   PDF, and EPUB builds.
 

Doc/c-api/dict.rst

@@ -290,6 +290,17 @@ Dictionary Objects
           Py_DECREF(o);
       }
 
+   The function is not thread-safe in the :term:`free-threaded <free threading>`
+   build without external synchronization.  You can use
+   :c:macro:`Py_BEGIN_CRITICAL_SECTION` to lock the dictionary while iterating
+   over it::
+
+      Py_BEGIN_CRITICAL_SECTION(self->dict);
+      while (PyDict_Next(self->dict, &pos, &key, &value)) {
+          ...
+      }
+      Py_END_CRITICAL_SECTION();
+
 
 .. c:function:: int PyDict_Merge(PyObject *a, PyObject *b, int override)
 

Doc/c-api/init.rst

@@ -55,6 +55,11 @@ The following functions can be safely called before Python is initialized:
   * :c:func:`PyMem_RawCalloc`
   * :c:func:`PyMem_RawFree`
 
+* Synchronization:
+
+  * :c:func:`PyMutex_Lock`
+  * :c:func:`PyMutex_Unlock`
+
 .. note::
 
    The following functions **should not be called** before
@@ -391,9 +396,16 @@ Initializing and finalizing the interpreter
    :c:func:`Py_NewInterpreter` below) that were created and not yet destroyed since
    the last call to :c:func:`Py_Initialize`.  Ideally, this frees all memory
    allocated by the Python interpreter.  This is a no-op when called for a second
-   time (without calling :c:func:`Py_Initialize` again first).  Normally the
-   return value is ``0``.  If there were errors during finalization
-   (flushing buffered data), ``-1`` is returned.
+   time (without calling :c:func:`Py_Initialize` again first).
+
+   Since this is the reverse of :c:func:`Py_Initialize`, it should be called
+   in the same thread with the same interpreter active.  That means
+   the main thread and the main interpreter.
+   This should never be called while :c:func:`Py_RunMain` is running.
+
+   Normally the return value is ``0``.
+   If there were errors during finalization (flushing buffered data),
+   ``-1`` is returned.
 
    This function is provided for a number of reasons.  An embedding application
    might want to restart Python without having to restart the application itself.
@@ -2152,3 +2164,145 @@ be used in new code.
 .. c:function:: void PyThread_delete_key_value(int key)
 .. c:function:: void PyThread_ReInitTLS()
 
+Synchronization Primitives
+==========================
+
+The C-API provides a basic mutual exclusion lock.
+
+.. c:type:: PyMutex
+
+   A mutual exclusion lock.  The :c:type:`!PyMutex` should be initialized to
+   zero to represent the unlocked state.  For example::
+
+      PyMutex mutex = {0};
+
+   Instances of :c:type:`!PyMutex` should not be copied or moved.  Both the
+   contents and address of a :c:type:`!PyMutex` are meaningful, and it must
+   remain at a fixed, writable location in memory.
+
+   .. note::
+
+      A :c:type:`!PyMutex` currently occupies one byte, but the size should be
+      considered unstable.  The size may change in future Python releases
+      without a deprecation period.
+
+   .. versionadded:: 3.13
+
+.. c:function:: void PyMutex_Lock(PyMutex *m)
+
+   Lock mutex *m*.  If another thread has already locked it, the calling
+   thread will block until the mutex is unlocked.  While blocked, the thread
+   will temporarily release the :term:`GIL` if it is held.
+
+   .. versionadded:: 3.13
+
+.. c:function:: void PyMutex_Unlock(PyMutex *m)
+
+   Unlock mutex *m*. The mutex must be locked --- otherwise, the function will
+   issue a fatal error.
+
+   .. versionadded:: 3.13
+
+.. _python-critical-section-api:
+
+Python Critical Section API
+---------------------------
+
+The critical section API provides a deadlock avoidance layer on top of
+per-object locks for :term:`free-threaded <free threading>` CPython.  They are
+intended to replace reliance on the :term:`global interpreter lock`, and are
+no-ops in versions of Python with the global interpreter lock.
+
+Critical sections avoid deadlocks by implicitly suspending active critical
+sections and releasing the locks during calls to :c:func:`PyEval_SaveThread`.
+When :c:func:`PyEval_RestoreThread` is called, the most recent critical section
+is resumed, and its locks reacquired.  This means the critical section API
+provides weaker guarantees than traditional locks -- they are useful because
+their behavior is similar to the :term:`GIL`.
+
+The functions and structs used by the macros are exposed for cases
+where C macros are not available. They should only be used as in the
+given macro expansions. Note that the sizes and contents of the structures may
+change in future Python versions.
+
+.. note::
+
+   Operations that need to lock two objects at once must use
+   :c:macro:`Py_BEGIN_CRITICAL_SECTION2`.  You *cannot* use nested critical
+   sections to lock more than one object at once, because the inner critical
+   section may suspend the outer critical sections.  This API does not provide
+   a way to lock more than two objects at once.
+
+Example usage::
+
+   static PyObject *
+   set_field(MyObject *self, PyObject *value)
+   {
+      Py_BEGIN_CRITICAL_SECTION(self);
+      Py_SETREF(self->field, Py_XNewRef(value));
+      Py_END_CRITICAL_SECTION();
+      Py_RETURN_NONE;
+   }
+
+In the above example, :c:macro:`Py_SETREF` calls :c:macro:`Py_DECREF`, which
+can call arbitrary code through an object's deallocation function.  The critical
+section API avoids potentital deadlocks due to reentrancy and lock ordering
+by allowing the runtime to temporarily suspend the critical section if the
+code triggered by the finalizer blocks and calls :c:func:`PyEval_SaveThread`.
+
+.. c:macro:: Py_BEGIN_CRITICAL_SECTION(op)
+
+   Acquires the per-object lock for the object *op* and begins a
+   critical section.
+
+   In the free-threaded build, this macro expands to::
+
+      {
+          PyCriticalSection _py_cs;
+          PyCriticalSection_Begin(&_py_cs, (PyObject*)(op))
+
+   In the default build, this macro expands to ``{``.
+
+   .. versionadded:: 3.13
+
+.. c:macro:: Py_END_CRITICAL_SECTION()
+
+   Ends the critical section and releases the per-object lock.
+
+   In the free-threaded build, this macro expands to::
+
+          PyCriticalSection_End(&_py_cs);
+      }
+
+   In the default build, this macro expands to ``}``.
+
+   .. versionadded:: 3.13
+
+.. c:macro:: Py_BEGIN_CRITICAL_SECTION2(a, b)
+
+   Acquires the per-objects locks for the objects *a* and *b* and begins a
+   critical section.  The locks are acquired in a consistent order (lowest
+   address first) to avoid lock ordering deadlocks.
+
+   In the free-threaded build, this macro expands to::
+
+      {
+          PyCriticalSection2 _py_cs2;
+          PyCriticalSection_Begin2(&_py_cs2, (PyObject*)(a), (PyObject*)(b))
+
+   In the default build, this macro expands to ``{``.
+
+   .. versionadded:: 3.13
+
+.. c:macro:: Py_END_CRITICAL_SECTION2()
+
+   Ends the critical section and releases the per-object locks.
+
+   In the free-threaded build, this macro expands to::
+
+          PyCriticalSection_End2(&_py_cs2);
+      }
+
+   In the default build, this macro expands to ``}``.
+
+   .. versionadded:: 3.13

Doc/c-api/typeobj.rst

@@ -1328,8 +1328,8 @@ and :c:data:`PyType_Type` effectively act as defaults.)
       To indicate that a class has changed call :c:func:`PyType_Modified`
 
       .. warning::
-         This flag is present in header files, but is an internal feature and should
-         not be used. It will be removed in a future version of CPython
+         This flag is present in header files, but is not be used.
+         It will be removed in a future version of CPython
 
 
 .. c:member:: const char* PyTypeObject.tp_doc