Merge branch 'main' into deepcopy_skip_memo

.github/workflows/build.yml

@@ -182,7 +182,7 @@ jobs:
     - name: Display build info
       run: .\python.bat -m test.pythoninfo
     - name: Tests
-      run: .\PCbuild\rt.bat -p Win32 -d -q -uall -u-cpu -rwW --slowest --timeout=1200 -j0
+      run: .\PCbuild\rt.bat -p Win32 -d -q --fast-ci
 
   build_win_amd64:
     name: 'Windows (x64)'
@@ -201,7 +201,7 @@ jobs:
     - name: Display build info
       run: .\python.bat -m test.pythoninfo
     - name: Tests
-      run: .\PCbuild\rt.bat -p x64 -d -q -uall -u-cpu -rwW --slowest --timeout=1200 -j0
+      run: .\PCbuild\rt.bat -p x64 -d -q --fast-ci
 
   build_win_arm64:
     name: 'Windows (arm64)'
@@ -252,7 +252,7 @@ jobs:
     - name: Display build info
       run: make pythoninfo
     - name: Tests
-      run: make buildbottest TESTOPTS="-j4 -uall,-cpu"
+      run: make test
 
   build_ubuntu:
     name: 'Ubuntu'
@@ -319,7 +319,7 @@ jobs:
       run: sudo mount $CPYTHON_RO_SRCDIR -oremount,rw
     - name: Tests
       working-directory: ${{ env.CPYTHON_BUILDDIR }}
-      run: xvfb-run make buildbottest TESTOPTS="-j4 -uall,-cpu"
+      run: xvfb-run make test
 
   build_ubuntu_ssltests:
     name: 'Ubuntu SSL tests with OpenSSL'
@@ -535,7 +535,7 @@ jobs:
     - name: Display build info
       run: make pythoninfo
     - name: Tests
-      run: xvfb-run make buildbottest TESTOPTS="-j4 -uall,-cpu"
+      run: xvfb-run make test
 
   all-required-green:  # This job does nothing and is only used for the branch protection
     name: All required checks pass

Doc/library/pathlib.rst

@@ -1381,15 +1381,19 @@ call fails (for example because the path doesn't exist).
       >>> p.resolve()
       PosixPath('/home/antoine/pathlib/setup.py')
 
-   If the path doesn't exist and *strict* is ``True``, :exc:`FileNotFoundError`
-   is raised.  If *strict* is ``False``, the path is resolved as far as possible
-   and any remainder is appended without checking whether it exists.  If an
-   infinite loop is encountered along the resolution path, :exc:`RuntimeError`
-   is raised.
+   If a path doesn't exist or a symlink loop is encountered, and *strict* is
+   ``True``, :exc:`OSError` is raised.  If *strict* is ``False``, the path is
+   resolved as far as possible and any remainder is appended without checking
+   whether it exists.
 
    .. versionchanged:: 3.6
       The *strict* parameter was added (pre-3.6 behavior is strict).
 
+   .. versionchanged:: 3.13
+      Symlink loops are treated like other errors: :exc:`OSError` is raised in
+      strict mode, and no exception is raised in non-strict mode. In previous
+      versions, :exc:`RuntimeError` is raised no matter the value of *strict*.
+
 .. method:: Path.rglob(pattern, *, case_sensitive=None, follow_symlinks=None)
 
    Glob the given relative *pattern* recursively.  This is like calling

Doc/library/weakref.rst

@@ -111,7 +111,7 @@ See :ref:`__slots__ documentation <slots>` for details.
 
    Exceptions raised by the callback will be noted on the standard error output,
    but cannot be propagated; they are handled in exactly the same way as exceptions
-   raised from an object's :meth:`__del__` method.
+   raised from an object's :meth:`~object.__del__` method.
 
    Weak references are :term:`hashable` if the *object* is hashable.  They will
    maintain their hash value even after the *object* was deleted.  If
@@ -221,8 +221,7 @@ than needed.
       Added support for ``|`` and ``|=`` operators, as specified in :pep:`584`.
 
 :class:`WeakValueDictionary` objects have an additional method that has the
-same issues as the :meth:`keyrefs` method of :class:`WeakKeyDictionary`
-objects.
+same issues as the :meth:`WeakKeyDictionary.keyrefs` method.
 
 
 .. method:: WeakValueDictionary.valuerefs()
@@ -281,7 +280,7 @@ objects.
    Exceptions raised by finalizer callbacks during garbage collection
    will be shown on the standard error output, but cannot be
    propagated.  They are handled in the same way as exceptions raised
-   from an object's :meth:`__del__` method or a weak reference's
+   from an object's :meth:`~object.__del__` method or a weak reference's
    callback.
 
    When the program exits, each remaining live finalizer is called
@@ -523,18 +522,18 @@ is still alive.  For instance
    obj dead or exiting
 
 
-Comparing finalizers with :meth:`__del__` methods
--------------------------------------------------
+Comparing finalizers with :meth:`~object.__del__` methods
+---------------------------------------------------------
 
 Suppose we want to create a class whose instances represent temporary
 directories.  The directories should be deleted with their contents
 when the first of the following events occurs:
 
 * the object is garbage collected,
-* the object's :meth:`remove` method is called, or
+* the object's :meth:`!remove` method is called, or
 * the program exits.
 
-We might try to implement the class using a :meth:`__del__` method as
+We might try to implement the class using a :meth:`~object.__del__` method as
 follows::
 
     class TempDir:
@@ -553,12 +552,12 @@ follows::
         def __del__(self):
             self.remove()
 
-Starting with Python 3.4, :meth:`__del__` methods no longer prevent
+Starting with Python 3.4, :meth:`~object.__del__` methods no longer prevent
 reference cycles from being garbage collected, and module globals are
 no longer forced to :const:`None` during :term:`interpreter shutdown`.
 So this code should work without any issues on CPython.
 
-However, handling of :meth:`__del__` methods is notoriously implementation
+However, handling of :meth:`~object.__del__` methods is notoriously implementation
 specific, since it depends on internal details of the interpreter's garbage
 collector implementation.
 

Doc/tools/.nitignore

@@ -133,7 +133,6 @@ Doc/library/unittest.mock.rst
 Doc/library/unittest.rst
 Doc/library/urllib.parse.rst
 Doc/library/urllib.request.rst
-Doc/library/weakref.rst
 Doc/library/wsgiref.rst
 Doc/library/xml.dom.minidom.rst
 Doc/library/xml.dom.pulldom.rst

Doc/using/configure.rst

@@ -964,9 +964,18 @@ Main Makefile targets
   You can use the configure :option:`--enable-optimizations` option to make
   this the default target of the ``make`` command (``make all`` or just
   ``make``).
-* ``make buildbottest``: Build Python and run the Python test suite, the same
-  way than buildbots test Python. Set ``TESTTIMEOUT`` variable (in seconds)
-  to change the test timeout (1200 by default: 20 minutes).
+
+* ``make test``: Build Python and run the Python test suite with ``--slow-ci``
+  option. Variables:
+
+  * ``TESTOPTS``: additional regrtest command line options.
+  * ``TESTPYTHONOPTS``: additional Python command line options.
+  * ``TESTTIMEOUT``: timeout in seconds (default: 20 minutes).
+
+* ``make buildbottest``: Similar to ``make test``, but use ``--slow-ci``
+  option and default timeout of 20 minutes, instead of ``--fast-ci`` option
+  and a default timeout of 10 minutes.
+
 * ``make install``: Build and install Python.
 * ``make regen-all``: Regenerate (almost) all generated files;
   ``make regen-stdlib-module-names`` and ``autoconf`` must be run separately

Doc/whatsnew/3.12.rst

@@ -752,7 +752,7 @@ random
 * Add :func:`random.binomialvariate`.
   (Contributed by Raymond Hettinger in :gh:`81620`.)
 
-* Add a default of ``lamb=1.0`` to :func:`random.expovariate`.
+* Add a default of ``lambd=1.0`` to :func:`random.expovariate`.
   (Contributed by Raymond Hettinger in :gh:`100234`.)
 
 shutil

Lib/concurrent/futures/process.py

@@ -521,7 +521,8 @@ def terminate_broken(self, cause):
 
         # gh-107219: Close the connection writer which can unblock
         # Queue._feed() if it was stuck in send_bytes().
-        self.call_queue._writer.close()
+        if sys.platform == 'win32':
+            self.call_queue._writer.close()
 
         # clean up resources
         self.join_executor_internals()

Lib/multiprocessing/connection.py

@@ -42,7 +42,6 @@
 BUFSIZE = 8192
 # A very generous timeout when it comes to local connections...
 CONNECTION_TIMEOUT = 20.
-WSA_OPERATION_ABORTED = 995
 
 _mmap_counter = itertools.count()
 
@@ -300,7 +299,7 @@ def _send_bytes(self, buf):
             finally:
                 self._send_ov = None
                 nwritten, err = ov.GetOverlappedResult(True)
-            if err == WSA_OPERATION_ABORTED:
+            if err == _winapi.ERROR_OPERATION_ABORTED:
                 # close() was called by another thread while
                 # WaitForMultipleObjects() was waiting for the overlapped
                 # operation.

Lib/multiprocessing/resource_tracker.py

@@ -51,15 +51,31 @@
     })
 
 
+class ReentrantCallError(RuntimeError):
+    pass
+
+
 class ResourceTracker(object):
 
     def __init__(self):
-        self._lock = threading.Lock()
+        self._lock = threading.RLock()
         self._fd = None
         self._pid = None
 
+    def _reentrant_call_error(self):
+        # gh-109629: this happens if an explicit call to the ResourceTracker
+        # gets interrupted by a garbage collection, invoking a finalizer (*)
+        # that itself calls back into ResourceTracker.
+        #   (*) for example the SemLock finalizer
+        raise ReentrantCallError(
+            "Reentrant call into the multiprocessing resource tracker")
+
     def _stop(self):
         with self._lock:
+            # This should not happen (_stop() isn't called by a finalizer)
+            # but we check for it anyway.
+            if self._lock._recursion_count() > 1:
+                return self._reentrant_call_error()
             if self._fd is None:
                 # not running
                 return
@@ -81,6 +97,9 @@ def ensure_running(self):
         This can be run from any process.  Usually a child process will use
         the resource created by its parent.'''
         with self._lock:
+            if self._lock._recursion_count() > 1:
+                # The code below is certainly not reentrant-safe, so bail out
+                return self._reentrant_call_error()
             if self._fd is not None:
                 # resource tracker was launched before, is it still running?
                 if self._check_alive():
@@ -159,7 +178,17 @@ def unregister(self, name, rtype):
         self._send('UNREGISTER', name, rtype)
 
     def _send(self, cmd, name, rtype):
-        self.ensure_running()
+        try:
+            self.ensure_running()
+        except ReentrantCallError:
+            # The code below might or might not work, depending on whether
+            # the resource tracker was already running and still alive.
+            # Better warn the user.
+            # (XXX is warnings.warn itself reentrant-safe? :-)
+            warnings.warn(
+                f"ResourceTracker called reentrantly for resource cleanup, "
+                f"which is unsupported. "
+                f"The {rtype} object {name!r} might leak.")
         msg = '{0}:{1}:{2}\n'.format(cmd, name, rtype).encode('ascii')
         if len(msg) > 512:
             # posix guarantees that writes to a pipe of less than PIPE_BUF
@@ -176,6 +205,7 @@ def _send(self, cmd, name, rtype):
 unregister = _resource_tracker.unregister
 getfd = _resource_tracker.getfd
 
+
 def main(fd):
     '''Run resource tracker.'''
     # protect the process from ^C and "killall python" etc

Lib/pathlib.py

@@ -1230,26 +1230,7 @@ def resolve(self, strict=False):
         normalizing it.
         """
 
-        def check_eloop(e):
-            winerror = getattr(e, 'winerror', 0)
-            if e.errno == ELOOP or winerror == _WINERROR_CANT_RESOLVE_FILENAME:
-                raise RuntimeError("Symlink loop from %r" % e.filename)
-
-        try:
-            s = os.path.realpath(self, strict=strict)
-        except OSError as e:
-            check_eloop(e)
-            raise
-        p = self.with_segments(s)
-
-        # In non-strict mode, realpath() doesn't raise on symlink loops.
-        # Ensure we get an exception by calling stat()
-        if not strict:
-            try:
-                p.stat()
-            except OSError as e:
-                check_eloop(e)
-        return p
+        return self.with_segments(os.path.realpath(self, strict=strict))
 
     def owner(self):
         """

Lib/random.py

@@ -492,7 +492,14 @@ def choices(self, population, weights=None, *, cum_weights=None, k=1):
     ## -------------------- real-valued distributions  -------------------
 
     def uniform(self, a, b):
-        "Get a random number in the range [a, b) or [a, b] depending on rounding."
+        """Get a random number in the range [a, b) or [a, b] depending on rounding.
+
+        The mean (expected value) and variance of the random variable are:
+
+            E[X] = (a + b) / 2
+            Var[X] = (b - a) ** 2 / 12
+
+        """
         return a + (b - a) * self.random()
 
     def triangular(self, low=0.0, high=1.0, mode=None):
@@ -503,6 +510,11 @@ def triangular(self, low=0.0, high=1.0, mode=None):
 
         http://en.wikipedia.org/wiki/Triangular_distribution
 
+        The mean (expected value) and variance of the random variable are:
+
+            E[X] = (low + high + mode) / 3
+            Var[X] = (low**2 + high**2 + mode**2 - low*high - low*mode - high*mode) / 18
+
         """
         u = self.random()
         try:
@@ -593,12 +605,15 @@ def expovariate(self, lambd=1.0):
         positive infinity if lambd is positive, and from negative
         infinity to 0 if lambd is negative.
 
-        """
-        # lambd: rate lambd = 1/mean
-        # ('lambda' is a Python reserved word)
+        The mean (expected value) and variance of the random variable are:
+
+            E[X] = 1 / lambd
+            Var[X] = 1 / lambd ** 2
 
+        """
         # we use 1-random() instead of random() to preclude the
         # possibility of taking the log of zero.
+
         return -_log(1.0 - self.random()) / lambd
 
     def vonmisesvariate(self, mu, kappa):
@@ -654,8 +669,12 @@ def gammavariate(self, alpha, beta):
           pdf(x) =  --------------------------------------
                       math.gamma(alpha) * beta ** alpha
 
+        The mean (expected value) and variance of the random variable are:
+
+            E[X] = alpha * beta
+            Var[X] = alpha * beta ** 2
+
         """
-        # alpha > 0, beta > 0, mean is alpha*beta, variance is alpha*beta**2
 
         # Warning: a few older sources define the gamma distribution in terms
         # of alpha > -1.0
@@ -714,6 +733,11 @@ def betavariate(self, alpha, beta):
         Conditions on the parameters are alpha > 0 and beta > 0.
         Returned values range between 0 and 1.
 
+        The mean (expected value) and variance of the random variable are:
+
+            E[X] = alpha / (alpha + beta)
+            Var[X] = alpha * beta / ((alpha + beta)**2 * (alpha + beta + 1))
+
         """
         ## See
         ## http://mail.python.org/pipermail/python-bugs-list/2001-January/003752.html
@@ -766,6 +790,11 @@ def binomialvariate(self, n=1, p=0.5):
 
         Returns an integer in the range:   0 <= X <= n
 
+        The mean (expected value) and variance of the random variable are:
+
+            E[X] = n * p
+            Var[x] = n * p * (1 - p)
+
         """
         # Error check inputs and handle edge cases
         if n < 0: