-/* Based on a test originally submitted for Stanford's CS 140 in
+/* The main thread acquires locks A and B, then it creates two
+ higher-priority threads. Each of these threads blocks
+ acquiring one of the locks and thus donate their priority to
+ the main thread. The main thread releases the locks in turn
+ and relinquishes its donated priorities.
+
+ Based on a test originally submitted for Stanford's CS 140 in
winter 1999 by Matt Franklin <startled@leland.stanford.edu>,
Greg Hutchins <gmh@leland.stanford.edu>, Yu Ping Hu
<yph@cs.stanford.edu>. Modified by arens. */