On macOS, ``sem_timedwait`` is unsupported, so calling ``acquire()`` with
a timeout will emulate that function's behavior using a sleeping loop.
-.. note::
-
- If the SIGINT signal generated by :kbd:`Ctrl-C` arrives while the main thread is
- blocked by a call to :meth:`BoundedSemaphore.acquire`, :meth:`Lock.acquire`,
- :meth:`RLock.acquire`, :meth:`Semaphore.acquire`, :meth:`Condition.acquire`
- or :meth:`Condition.wait` then the call will be immediately interrupted and
- :exc:`KeyboardInterrupt` will be raised.
-
- This differs from the behaviour of :mod:`threading` where SIGINT will be
- ignored while the equivalent blocking calls are in progress.
-
.. note::
Some of this package's functionality requires a functioning shared semaphore