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authorJorge Aparicio <jorge@japaric.io>2018-11-03 17:02:41 +0100
committerJorge Aparicio <jorge@japaric.io>2018-11-03 17:16:55 +0100
commitc631049efcadca8b07940c794cce2be58fa48444 (patch)
treef6bd73e5c396fc06072557ee965cc59e9c8e3e9f /examples/preemption.rs
parent653338e7997a0cdc5deaed98b1bb5f60006717ed (diff)
v0.4.0
closes #32 closes #33
Diffstat (limited to 'examples/preemption.rs')
-rw-r--r--examples/preemption.rs67
1 files changed, 0 insertions, 67 deletions
diff --git a/examples/preemption.rs b/examples/preemption.rs
deleted file mode 100644
index 340b976..0000000
--- a/examples/preemption.rs
+++ /dev/null
@@ -1,67 +0,0 @@
-//! Two tasks running at *different* priorities with access to the same resource
-#![deny(unsafe_code)]
-#![deny(warnings)]
-#![no_std]
-
-extern crate cortex_m_rtfm as rtfm;
-extern crate stm32f103xx;
-
-use rtfm::{app, Resource, Threshold};
-
-app! {
- device: stm32f103xx,
-
- resources: {
- static COUNTER: u64 = 0;
- },
-
- tasks: {
- // The `SYS_TICK` task has higher priority than `TIM2`
- SYS_TICK: {
- path: sys_tick,
- priority: 2,
- resources: [COUNTER],
- },
-
- TIM2: {
- path: tim2,
- priority: 1,
- resources: [COUNTER],
- },
- },
-}
-
-fn init(_p: init::Peripherals, _r: init::Resources) {
- // ..
-}
-
-fn idle() -> ! {
- loop {
- rtfm::wfi();
- }
-}
-
-fn sys_tick(_t: &mut Threshold, mut r: SYS_TICK::Resources) {
- // ..
-
- // This task can't be preempted by `tim2` so it has direct access to the
- // resource data
- *r.COUNTER += 1;
-
- // ..
-}
-
-fn tim2(t: &mut Threshold, mut r: TIM2::Resources) {
- // ..
-
- // As this task runs at lower priority it needs a critical section to
- // prevent `sys_tick` from preempting it while it modifies this resource
- // data. The critical section is required to prevent data races which can
- // lead to undefined behavior.
- r.COUNTER.claim_mut(t, |counter, _t| {
- // `claim_mut` creates a critical section
- *counter += 1;
- });
-
- // ..
-}