* Add _PyRuntime.pre_initialized: set to 1 when Python
is pre-initialized
* Add _Py_PreInitialize() and _Py_PreInitializeFromPreConfig().
* _PyCoreConfig_Read() now calls _Py_PreInitialize().
* Move _PyPreConfig_GetGlobalConfig() and
_PyCoreConfig_GetGlobalConfig() calls from main.c to preconfig.c
and coreconfig.c.
No longer limit repr(structseq) to 512 bytes. Use _PyUnicodeWriter
for better performance and to write directly Unicode rather than
encoding repr() value to UTF-8 and then decoding from UTF-8.
Calling _PyRuntime_Initialize() after _PyRuntime_Finalize() now re-initializes
_PyRuntime structure. Previously, _PyRuntime_Initialize() did
nothing in that case.
* _PyPathConfig_ComputeSysPath0() now returns 0 if argv is empty.
* Cleanup also _PyPathConfig_ComputeSysPath0() code: move variables
definitions closer to where they are used.
At Python initialization, the current directory is no longer
prepended to sys.path if it has been removed.
Rename _PyPathConfig_ComputeArgv0() to
_PyPathConfig_ComputeSysPath0() to avoid confusion between argv[0]
and sys.path[0].
When Python is compiled with Valgrind support, release Unicode
interned strings at exit in _PyUnicode_Fini().
* Rename _Py_ReleaseInternedUnicodeStrings() to
unicode_release_interned() and make it private.
* unicode_release_interned() is now called from _PyUnicode_Fini():
it must be called with a running Python thread state for TRASHCAN,
it cannot be called from pymain_free().
* Don't display statistics on interned strings at exit anymore
Python initialization now fails if decoding pybuilddir.txt
configuration file fails at startup.
_PyPathConfig_Calculate() now reports memory allocation failure and
decoding error on decoding pybuilddir.txt content from
UTF-8/surrogateescape.
The last parameter of _Py_wreadlink(), _Py_wrealpath() and
_Py_wgetcwd() is a length, not a size: number of characters including
the trailing NUL character.
Enhance also documentation of error conditions.
* bpo-35493: Use Process.sentinel instead of sleeping for polling worker status in multiprocessing.Pool
* Use self-pipe pattern to avoid polling for changes
* Refactor some variable names and add comments
* Restore timeout and poll
* Use reader object only on wait()
* Recompute worker sentinels every time
* Remove timeout and use change notifier
* Refactor some methods to be overloaded by the ThreadPool, document the cache class and fix typos
ProcessPoolExecutor workers will hold the return value of their last task in memory until the next task is received. Since the return value has already been propagated to the parent process's Future (or has been discarded by this point), the object can be safely released.
* Replace external recipe link with a link to the dataclasses module.
* Highlight the class definition syntax for typing.NamedTuple
and add an example for clarity.