python/cpython

When Py_Initialize() is called twice, the second call now updates
more sys attributes for the configuration, rather than only sys.argv.

* Rename _PySys_InitMain() to _PySys_UpdateConfig().
* _PySys_UpdateConfig() now modifies sys.flags in-place, instead of
  creating a new flags object.
* Remove old commented sys.flags flags (unbuffered and skip_first).
* Add private _PySys_GetObject() function.
* When Py_Initialize(), Py_InitializeFromConfig() and

* Move orig_argv before argv
* Move program_name and platlibdir with other path configuration
  inputs

Give a name to the PyPreConfig and PyConfig structures and separate
the type definitions.

Call _PyAST_Fini() on all interpreters, not only on the main
interpreter. Also, call it ealier to fix a reference leak.

Python types contain a reference to themselves in in their
PyTypeObject.tp_mro member. _PyAST_Fini() must called before the last
GC collection to destroy AST types.

_PyInterpreterState_Clear() now calls _PyAST_Fini(). It now also
calls _PyWarnings_Fini() on subinterpeters, not only on the main
interpreter.

Add an assertion in AST init_types() to ensure that the _ast module
is no longer used after _PyAST_Fini() has been called.

The logging.FileHandler class now keeps a reference to the builtin
open() function to be able to open or reopen the file during Python
finalization.

Fix errors like:

    Exception ignored in: (...)
    Traceback (most recent call last):
      (...)
      File ".../logging/__init__.py", line 1463, in error
      File ".../logging/__init__.py", line 1577, in _log
      File ".../logging/__init__.py", line 1587, in handle
      File ".../logging/__init__.py", line 1649, in callHandlers
      File ".../logging/__init__.py", line 948, in handle
      File ".../logging/__init__.py", line 1182, in emit
      File ".../logging/__init__.py", line 1171, in _open
    NameError: name 'open' is not defined

The ast module internal state is now per interpreter.

* Rename "astmodulestate" to "struct ast_state"
* Add pycore_ast.h internal header: the ast_state structure is now
  declared in pycore_ast.h.
* Add PyInterpreterState.ast (struct ast_state)
* Remove get_ast_state()
* Rename get_global_ast_state() to get_ast_state()
* PyAST_obj2mod() now handles get_ast_state() failures

* Prevent some possible DoS attacks via providing invalid Plist files
  with extremely large number of objects or collection sizes.
* Raise InvalidFileException for too large bytes and string size instead of returning garbage.
* Raise InvalidFileException instead of ValueError for specific invalid datetime (NaN).
* Raise InvalidFileException instead of TypeError for non-hashable dict keys.
* Add more tests for invalid Plist files.

Enhance the documentation of the Python startup, filesystem encoding
and error handling, locale encoding. Add a new "Python UTF-8 Mode"
section.

* Add "locale encoding" and "filesystem encoding and error handler"
  to the glossary
* Remove documentation from Include/cpython/initconfig.h: move it to
  Doc/c-api/init_config.rst.
* Doc/c-api/init_config.rst:

  * Document command line options and environment variables
  * Document default values.

* Add a new "Python UTF-8 Mode" section in Doc/library/os.rst.
* Add warnings to Py_DecodeLocale() and Py_EncodeLocale() docs.
* Document how Python selects the filesystem encoding and error
  handler at a single place: PyConfig.filesystem_encoding and
  PyConfig.filesystem_errors.
* PyConfig: move orig_argv member at the right place.

This adds a new function named sys._current_exceptions() which is equivalent ot
sys._current_frames() except that it returns the exceptions currently handled
by other threads. It is equivalent to calling sys.exc_info() for each running
thread.

…H-13893)

* bpo-37193: remove the thread which finished process request from threads list

* rename variable t to thread.

* don't remove thread from list if it is daemon.

* use lock to protect self._threads.

* use finally block in case of exception from shutdown_request().

* check "not thread.daemon" before lock to avoid holding the lock if it's unnecessary.

* fix the place of _threads_lock.

* separate code to remove a current thread into a function.

* check ValueError when removing thread.

* fix wrong code which all instance shared same lock.

* Extract thread management into a _Threads class to encapsulate atomic operations and separate concerns.

* Replace multiple references of 'block_on_close' with one, avoiding the possibility that 'block_on_close' could change during the course of processing requests. Now, there's exactly one _threads object with behavior fixed for the duration.

* Add docstrings to private classes.

* Add test to ensure that a ThreadingTCPServer can be closed without serving any requests.

* Use _NoThreads as the default value. Fixes AttributeError when server is closed without serving any requests.

* Add blurb

* Add test capturing failure.

Co-authored-by: Jason R. Coombs <jaraco@jaraco.com>

If the nl_langinfo(CODESET) function returns an empty string, Python
now uses UTF-8 as the filesystem encoding.

In May 2010 (commit b744ba1), I
modified Python to log a warning and use UTF-8 as the filesystem
encoding (instead of None) if nl_langinfo(CODESET) returns an empty
string.

In August 2020 (commit 94908bb), I
modified Python startup to fail with a fatal error and a specific
error message if nl_langinfo(CODESET) returns an empty string. The
intent was to prevent guessing the encoding and also investigate user
configuration where this case happens.

In 10 years (2010 to 2020), I saw zero user report about the error
message related to nl_langinfo(CODESET) returning an empty string.

Today, UTF-8 became the defacto standard and it's safe to make the
assumption that the user expects UTF-8. For example,
nl_langinfo(CODESET) can return an empty string on macOS if the
LC_CTYPE locale is not supported, and UTF-8 is the default encoding
on macOS.

While this change is likely to not affect anyone in practice, it
should make UTF-8 lover happy ;-)

Rewrite also the documentation explaining how Python selects the
filesystem encoding and error handler.

* Rename _Py_GetLocaleEncoding() to _Py_GetLocaleEncodingObject()
* Add _Py_GetLocaleEncoding() which returns a wchar_t* string to
  share code between _Py_GetLocaleEncodingObject()
  and config_get_locale_encoding().
* _Py_GetLocaleEncodingObject() now decodes nl_langinfo(CODESET)
  from the current locale encoding with surrogateescape,
  rather than using UTF-8.