tpool(n) on macOS
The text e0ec49316ca8, as Mac OS X 10.6.8, Mac OS X 10.6.7, Mac OS X 10.6.6, Mac OS X 10.6.5, Mac OS X 10.6.4, Mac OS X 10.6.3, Mac OS X 10.6.2, Mac OS X 10.6.1, Mac OS X 10.6 shipped it.
Part of the Tcl threading extension implementing pools of worker threads.
Flags it lists
-
-exitcmd -
-idletime -
-initcmd -
-maxthreads -
-minthreads