sem_post(2) on macOS
The text 29894bcab568, as Mac OS X 10.1.5, Mac OS X 10.1.4, Mac OS X 10.1.3, Mac OS X 10.1.2, Mac OS X 10.1.1, Mac OS X 10.1, Mac OS X 10.0.4, Mac OS X 10.0.1, Mac OS X 10.0 shipped it.
unlock a semaphore
The text 29894bcab568, as Mac OS X 10.1.5, Mac OS X 10.1.4, Mac OS X 10.1.3, Mac OS X 10.1.2, Mac OS X 10.1.1, Mac OS X 10.1, Mac OS X 10.0.4, Mac OS X 10.0.1, Mac OS X 10.0 shipped it.
unlock a semaphore