This document defines the coverage for the pthread_cancel function:

Assertion	Tested?
1		YES
2		YES ** Difficult to test and assert that date destructors
		       have been called (read assertions.xml file for more).
3		YES
4		YES
5		YES ** Keeping in mind it 'may' fail and not 'shall' fail,
		       so it will always return PASS, but will return a
		       PASS and print out a warning if it fails.

NOTE: In a lot of these test, I didn't make use of semaphores or mutexes, but
rather manually created my own.  This is because I was taking into account
different implementations.