Merge branch '3.12' into backport-109619-312

.gitattributes

@@ -25,7 +25,7 @@ PC/classicAppCompat.* binary
 [attr]noeol -text
 
 Lib/test/cjkencodings/*                    noeol
-Lib/test/coding20731.py                    noeol
+Lib/test/tokenizedata/coding20731.py       noeol
 Lib/test/decimaltestdata/*.decTest         noeol
 Lib/test/test_email/data/*.txt             noeol
 Lib/test/test_importlib/resources/data01/*           noeol

.pre-commit-config.yaml

@@ -15,7 +15,7 @@ repos:
       - id: check-yaml
       - id: end-of-file-fixer
         types: [python]
-        exclude: Lib/test/coding20731.py
+        exclude: Lib/test/tokenizedata/coding20731.py
       - id: trailing-whitespace
         types_or: [c, python, rst]
 

Grammar/python.gram

@@ -19,8 +19,6 @@ _PyPegen_parse(Parser *p)
         result = eval_rule(p);
     } else if (p->start_rule == Py_func_type_input) {
         result = func_type_rule(p);
-    } else if (p->start_rule == Py_fstring_input) {
-        result = fstring_rule(p);
     }
 
     return result;
@@ -89,7 +87,6 @@ file[mod_ty]: a=[statements] ENDMARKER { _PyPegen_make_module(p, a) }
 interactive[mod_ty]: a=statement_newline { _PyAST_Interactive(a, p->arena) }
 eval[mod_ty]: a=expressions NEWLINE* ENDMARKER { _PyAST_Expression(a, p->arena) }
 func_type[mod_ty]: '(' a=[type_expressions] ')' '->' b=expression NEWLINE* ENDMARKER { _PyAST_FunctionType(a, b, p->arena) }
-fstring[expr_ty]: star_expressions
 
 # GENERAL STATEMENTS
 # ==================
@@ -647,20 +644,20 @@ type_param_seq[asdl_type_param_seq*]: a[asdl_type_param_seq*]=','.type_param+ ['
 
 type_param[type_param_ty] (memo):
     | a=NAME b=[type_param_bound] { _PyAST_TypeVar(a->v.Name.id, b, EXTRA) }
-    | '*' a=NAME colon=":" e=expression {
+    | '*' a=NAME colon=':' e=expression {
             RAISE_SYNTAX_ERROR_STARTING_FROM(colon, e->kind == Tuple_kind
                 ? "cannot use constraints with TypeVarTuple"
                 : "cannot use bound with TypeVarTuple")
         }
     | '*' a=NAME { _PyAST_TypeVarTuple(a->v.Name.id, EXTRA) }
-    | '**' a=NAME colon=":" e=expression {
+    | '**' a=NAME colon=':' e=expression {
             RAISE_SYNTAX_ERROR_STARTING_FROM(colon, e->kind == Tuple_kind
                 ? "cannot use constraints with ParamSpec"
                 : "cannot use bound with ParamSpec")
         }
     | '**' a=NAME { _PyAST_ParamSpec(a->v.Name.id, EXTRA) }
 
-type_param_bound[expr_ty]: ":" e=expression { e }
+type_param_bound[expr_ty]: ':' e=expression { e }
 
 # EXPRESSIONS
 # -----------
@@ -915,7 +912,7 @@ fstring_middle[expr_ty]:
     | fstring_replacement_field
     | t=FSTRING_MIDDLE { _PyPegen_constant_from_token(p, t) }
 fstring_replacement_field[expr_ty]:
-    | '{' a=(yield_expr | star_expressions) debug_expr="="? conversion=[fstring_conversion] format=[fstring_full_format_spec] rbrace='}' {
+    | '{' a=(yield_expr | star_expressions) debug_expr='='? conversion=[fstring_conversion] format=[fstring_full_format_spec] rbrace='}' {
         _PyPegen_formatted_value(p, a, debug_expr, conversion, format, rbrace, EXTRA) }
     | invalid_replacement_field
 fstring_conversion[ResultTokenWithMetadata*]:

Include/compile.h

@@ -10,9 +10,6 @@ extern "C" {
 #define Py_eval_input 258
 #define Py_func_type_input 345
 
-/* This doesn't need to match anything */
-#define Py_fstring_input 800
-
 #ifndef Py_LIMITED_API
 #  define Py_CPYTHON_COMPILE_H
 #  include "cpython/compile.h"

Lib/asyncio/subprocess.py

@@ -147,15 +147,17 @@ def kill(self):
 
     async def _feed_stdin(self, input):
         debug = self._loop.get_debug()
-        if input is not None:
-            self.stdin.write(input)
-            if debug:
-                logger.debug(
-                    '%r communicate: feed stdin (%s bytes)', self, len(input))
         try:
+            if input is not None:
+                self.stdin.write(input)
+                if debug:
+                    logger.debug(
+                        '%r communicate: feed stdin (%s bytes)', self, len(input))
+
             await self.stdin.drain()
         except (BrokenPipeError, ConnectionResetError) as exc:
-            # communicate() ignores BrokenPipeError and ConnectionResetError
+            # communicate() ignores BrokenPipeError and ConnectionResetError.
+            # write() and drain() can raise these exceptions.
             if debug:
                 logger.debug('%r communicate: stdin got %r', self, exc)
 

Lib/concurrent/futures/process.py

@@ -71,6 +71,11 @@ def __init__(self):
         self._reader, self._writer = mp.Pipe(duplex=False)
 
     def close(self):
+        # Please note that we do not take the shutdown lock when
+        # calling clear() (to avoid deadlocking) so this method can
+        # only be called safely from the same thread as all calls to
+        # clear() even if you hold the shutdown lock. Otherwise we
+        # might try to read from the closed pipe.
         if not self._closed:
             self._closed = True
             self._writer.close()
@@ -426,8 +431,12 @@ def wait_result_broken_or_wakeup(self):
         elif wakeup_reader in ready:
             is_broken = False
 
-        with self.shutdown_lock:
-            self.thread_wakeup.clear()
+        # No need to hold the _shutdown_lock here because:
+        # 1. we're the only thread to use the wakeup reader
+        # 2. we're also the only thread to call thread_wakeup.close()
+        # 3. we want to avoid a possible deadlock when both reader and writer
+        #    would block (gh-105829)
+        self.thread_wakeup.clear()
 
         return result_item, is_broken, cause
 
@@ -710,7 +719,10 @@ def __init__(self, max_workers=None, mp_context=None,
         # as it could result in a deadlock if a worker process dies with the
         # _result_queue write lock still acquired.
         #
-        # _shutdown_lock must be locked to access _ThreadWakeup.
+        # _shutdown_lock must be locked to access _ThreadWakeup.close() and
+        # .wakeup(). Care must also be taken to not call clear or close from
+        # more than one thread since _ThreadWakeup.clear() is not protected by
+        # the _shutdown_lock
         self._executor_manager_thread_wakeup = _ThreadWakeup()
 
         # Create communication channels for the executor

Lib/test/.ruff.toml

@@ -22,7 +22,7 @@ extend-exclude = [
     "test_capi/test_unicode.py",
     "test_ctypes/test_arrays.py",
     "test_ctypes/test_functions.py",
-    "test_dataclasses.py",
+    "test_dataclasses/__init__.py",
     "test_descr.py",
     "test_enum.py",
     "test_functools.py",

Lib/test/_test_multiprocessing.py

@@ -5434,7 +5434,9 @@ def test_nested_startmethod(self):
         while not queue.empty():
             results.append(queue.get())
 
-        self.assertEqual(results, [2, 1])
+        # gh-109706: queue.put(1) can write into the queue before queue.put(2),
+        # there is no synchronization in the test.
+        self.assertSetEqual(set(results), set([2, 1]))
 
 
 @unittest.skipIf(sys.platform == "win32",

Lib/test/libregrtest/runtest.py

@@ -232,6 +232,7 @@ def iter_tests(self):
 SPLITTESTDIRS = {
     "test_asyncio",
     "test_concurrent_futures",
+    "test_future_stmt",
     "test_multiprocessing_fork",
     "test_multiprocessing_forkserver",
     "test_multiprocessing_spawn",