This document defines the coverage for the pthread_mutex_unlock function:

Assertion	Tested?
1		YES
2		YES * Because the default scheduling policy is implementation
		      dependent, the case only will only demo the scheduling
		      sequence instead of testing it.
3		YES
4		NO  * The related error codes are all implementation dependent
		    * 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.
5               YES

NOTE:
