| NAME = "Priority inversion tests" |
| AUTHOR = "Michal Piotrowski <michal.k.k.piotrowski@gmail.com>" |
| TIME = "SHORT" |
| TEST_CATEGORY = "FUNCTIONAL" |
| TEST_CLASS = "KERNEL" |
| TEST_TYPE = "CLIENT" |
| DOC = """ |
| The basic premise here is to set up a deadlock scenario and confirm that PI |
| mutexes resolve the situation. Three worker threads will be created from the |
| main thread: low, medium and high priority threads that use SCHED_FIFO as |
| their scheduling policy. The low priority thread claims a mutex and then |
| starts "working". The medium priority thread starts and preempts the low |
| priority thread. Then the high priority thread runs and attempts to claim |
| the mutex owned by the low priority thread. Without priority inheritance, |
| this will deadlock the program. With priority inheritance, the low priority |
| thread receives a priority boost, finishes it's "work" and releases the mutex, |
| which allows the high priority thread to run and finish and then the medium |
| priority thread finishes. |
| |
| That's the theory, anyway... |
| """ |
| |
| job.run_test('pi_tests') |
