Pull in main

Author: erlend-aasland

.github/workflows/require-pr-label.yml

@@ -4,6 +4,10 @@ on:
   pull_request:
     types: [opened, reopened, labeled, unlabeled, synchronize]
 
+permissions:
+  issues: read
+  pull-requests: read
+
 jobs:
   label:
     name: DO-NOT-MERGE / unresolved review

Doc/library/asyncio-task.rst

@@ -527,6 +527,8 @@ Running Tasks Concurrently
       and there is no running event loop.
 
 
+.. _eager-task-factory:
+
 Eager Task Factory
 ==================
 
@@ -1174,8 +1176,17 @@ Task Object
 
       Return the coroutine object wrapped by the :class:`Task`.
 
+      .. note::
+
+         This will return ``None`` for Tasks which have already
+         completed eagerly. See the :ref:`Eager Task Factory <eager-task-factory>`.
+
       .. versionadded:: 3.8
 
+      .. versionchanged:: 3.12
+
+         Newly added eager task execution means result may be ``None``.
+
    .. method:: get_context()
 
       Return the :class:`contextvars.Context` object

Doc/library/dis.rst

@@ -1196,6 +1196,14 @@ iterations of the loop.
 
    .. versionadded:: 3.12
 
+.. opcode:: LOAD_FAST_AND_CLEAR (var_num)
+
+   Pushes a reference to the local ``co_varnames[var_num]`` onto the stack (or
+   pushes ``NULL`` onto the stack if the local variable has not been
+   initialized) and sets ``co_varnames[var_num]`` to ``NULL``.
+
+   .. versionadded:: 3.12
+
 .. opcode:: STORE_FAST (var_num)
 
    Stores ``STACK.pop()`` into the local ``co_varnames[var_num]``.

Doc/library/http.client.rst

@@ -264,7 +264,10 @@ HTTPConnection Objects
             encode_chunked=False)
 
    This will send a request to the server using the HTTP request
-   method *method* and the selector *url*.
+   method *method* and the request URI *url*. The provided *url* must be
+   an absolute path to conform with :rfc:`RFC 2616 §5.1.2 <2616#section-5.1.2>`
+   (unless connecting to an HTTP proxy server or using the ``OPTIONS`` or
+   ``CONNECT`` methods).
 
    If *body* is specified, the specified data is sent after the headers are
    finished.  It may be a :class:`str`, a :term:`bytes-like object`, an
@@ -279,7 +282,10 @@ HTTPConnection Objects
    iterable are sent as is until the iterable is exhausted.
 
    The *headers* argument should be a mapping of extra HTTP headers to send
-   with the request.
+   with the request. A :rfc:`Host header <2616#section-14.23>`
+   must be provided to conform with :rfc:`RFC 2616 §5.1.2 <2616#section-5.1.2>`
+   (unless connecting to an HTTP proxy server or using the ``OPTIONS`` or
+   ``CONNECT`` methods).
 
    If *headers* contains neither Content-Length nor Transfer-Encoding,
    but there is a request body, one of those
@@ -298,6 +304,16 @@ HTTPConnection Objects
    HTTPConnection object assumes that all encoding is handled by the
    calling code.  If it is ``True``, the body will be chunk-encoded.
 
+   For example, to perform a ``GET`` request to ``https://docs.python.org/3/``::
+
+      >>> import http.client
+      >>> host = "docs.python.org"
+      >>> conn = http.client.HTTPSConnection(host)
+      >>> conn.request("GET", "/3/", headers={"Host": host})
+      >>> response = conn.getresponse()
+      >>> print(response.status, response.reason)
+      200 OK
+
    .. note::
       Chunked transfer encoding has been added to the HTTP protocol
       version 1.1.  Unless the HTTP server is known to handle HTTP 1.1,

Doc/whatsnew/3.12.rst

@@ -153,6 +153,30 @@ New Features
   In Python 3.14, the default will switch to ``'data'``.
   (Contributed by Petr Viktorin in :pep:`706`.)
 
+.. _whatsnew312-pep709:
+
+PEP 709: Comprehension inlining
+-------------------------------
+
+Dictionary, list, and set comprehensions are now inlined, rather than creating a
+new single-use function object for each execution of the comprehension. This
+speeds up execution of a comprehension by up to 2x.
+
+Comprehension iteration variables remain isolated; they don't overwrite a
+variable of the same name in the outer scope, nor are they visible after the
+comprehension. This isolation is now maintained via stack/locals manipulation,
+not via separate function scope.
+
+Inlining does result in a few visible behavior changes:
+
+* There is no longer a separate frame for the comprehension in tracebacks,
+  and tracing/profiling no longer shows the comprehension as a function call.
+* Calling :func:`locals` inside a comprehension now includes variables
+  from outside the comprehension, and no longer includes the synthetic ``.0``
+  variable for the comprehension "argument".
+
+Contributed by Carl Meyer and Vladimir Matveev in :pep:`709`.
+
 PEP 688: Making the buffer protocol accessible in Python
 --------------------------------------------------------
 
@@ -282,6 +306,11 @@ asyncio
   writing to sockets and uses :meth:`~socket.socket.sendmsg` if the platform
   supports it. (Contributed by Kumar Aditya in :gh:`91166`.)
 
+* Added :func:`asyncio.eager_task_factory` and :func:`asyncio.create_eager_task_factory`
+  functions to allow opting an event loop in to eager task execution,
+  making some use-cases 2x to 5x faster.
+  (Contributed by Jacob Bower & Itamar O in :gh:`102853`, :gh:`104140`, and :gh:`104138`)
+
 * On Linux, :mod:`asyncio` uses :class:`~asyncio.PidfdChildWatcher` by default
   if :func:`os.pidfd_open` is available and functional instead of
   :class:`~asyncio.ThreadedChildWatcher`.
@@ -644,11 +673,6 @@ Optimizations
 * Speed up :class:`asyncio.Task` creation by deferring expensive string formatting.
   (Contributed by Itamar O in :gh:`103793`.)
 
-* Added :func:`asyncio.eager_task_factory` and :func:`asyncio.create_eager_task_factory`
-  functions to allow opting an event loop in to eager task execution,
-  speeding up some use-cases by up to 50%.
-  (Contributed by Jacob Bower & Itamar O in :gh:`102853`)
-
 
 CPython bytecode changes
 ========================

Include/internal/pycore_code.h

@@ -131,6 +131,7 @@ struct callable_cache {
 // Note that these all fit within a byte, as do combinations.
 // Later, we will use the smaller numbers to differentiate the different
 // kinds of locals (e.g. pos-only arg, varkwargs, local-only).
+#define CO_FAST_HIDDEN  0x10
 #define CO_FAST_LOCAL   0x20
 #define CO_FAST_CELL    0x40
 #define CO_FAST_FREE    0x80

Include/internal/pycore_compile.h

@@ -70,6 +70,9 @@ typedef struct {
     PyObject *u_varnames;  /* local variables */
     PyObject *u_cellvars;  /* cell variables */
     PyObject *u_freevars;  /* free variables */
+    PyObject *u_fasthidden; /* dict; keys are names that are fast-locals only
+                               temporarily within an inlined comprehension. When
+                               value is True, treat as fast-local. */
 
     Py_ssize_t u_argcount;        /* number of arguments for block */
     Py_ssize_t u_posonlyargcount;        /* number of positional only arguments for block */

Include/internal/pycore_flowgraph.h

@@ -94,7 +94,7 @@ _PyCfgInstruction* _PyCfg_BasicblockLastInstr(const _PyCfgBasicblock *b);
 int _PyCfg_OptimizeCodeUnit(_PyCfgBuilder *g, PyObject *consts, PyObject *const_cache,
                             int code_flags, int nlocals, int nparams, int firstlineno);
 int _PyCfg_Stackdepth(_PyCfgBasicblock *entryblock, int code_flags);
-void _PyCfg_ConvertExceptionHandlersToNops(_PyCfgBasicblock *entryblock);
+void _PyCfg_ConvertPseudoOps(_PyCfgBasicblock *entryblock);
 int _PyCfg_ResolveJumps(_PyCfgBuilder *g);
 
 

Include/internal/pycore_opcode.h

@@ -64,6 +64,7 @@ typedef struct _symtable_entry {
     unsigned ste_needs_class_closure : 1; /* for class scopes, true if a
                                              closure over __class__
                                              should be created */
+    unsigned ste_comp_inlined : 1; /* true if this comprehension is inlined */
     unsigned ste_comp_iter_target : 1; /* true if visiting comprehension target */
     int ste_comp_iter_expr; /* non-zero if visiting a comprehension range expression */
     int ste_lineno;          /* first line of block */