Replace direct accesses to sched_active_thread and sched_active_pid with the helper functions thread_getpid() and thread_get_active(). This serves two purposes: 1. It makes accidental writes to those variable from outside core less likely. 2. Casting off the volatile qualifier is now well contained to those two functions
Trickle Test
This test starts a trickle timer and roughly checks the diff between two
intervals to be greater than the diff of previous intervals.
After 5 callbacks, the trickle timer is reset and ends after another 7
callbacks with either [SUCCESS] or [FAILURE]. The application exits with
[FAILURE] as soon as one diff is not greater than the previous diff.