`Py_HAVE_CONDVAR` denotes support for Python condition variable APIs. On Win32, the `_PY_EMULATED_WIN_CV` macro exists to allow condition variables to be emulated using Win32 critical section and semaphore APIs. [Native Win32 support for condition variables](https://learn.microsoft.com/en-us/windows/win32/sync/using-condition-variables) has existed from Windows Vista onwards (courtesy of my friend and fellow ex-MSFT colleague Neill Clift). An implementation of Python condition variable also exists with `_PY_EMULATED_WIN_CV` set to `0` which uses native Win32 condition variable / SRW lock (mutex) support. Since [support for Windows XP was dropped as of Python 3.5](https://docs.python.org/3.5/whatsnew/3.5.html#unsupported-operating-systems), I propose moving to the native Win32 condition variable APIs, as they are more efficient and easier to maintain. <!-- gh-linked-prs --> ### Linked PRs * gh-104531 <!-- /gh-linked-prs -->