extern crate cortex_m_rtfm as rtfm; use rtfm::{C2, C4, P1, P3, Resource}; static R1: Resource = Resource::new(0); fn j1(prio: P1) { let ceil = prio.as_ceiling(); ceil.raise( &R1, |ceil| { let r1 = R1.access(&prio, ceil); // `j2` preempts this critical section rtfm::request(j2); } ); } fn j2(_task: Task, prio: P3) { rtfm::atomic( |ceil| { // OK C2 (R1's ceiling) <= C16 (system ceiling) // BAD C2 (R1's ceiling) < P3 (j2's priority) let r1 = R1.access(&prio, &ceil); //~^ error }, ); } // glue extern crate cortex_m; use cortex_m::ctxt::Context; use cortex_m::interrupt::Nr; struct Task; unsafe impl Context for Task {} unsafe impl Nr for Task { fn nr(&self) -> u8 { 0 } }