1 Testing priority donation.
2 If the statements printed below are all true, you pass.
3 1. This thread should have priority 30. Actual priority: 30.
4 2. This thread should have priority 31. Actual priority: 31.
5 3. acquire2: got the lock
7 5. acquire1: got the lock
9 7. acquire2, acquire1 must already have finished, in that order.
10 8. This should be the last line before finishing this test.
11 Priority donation test done.