1 files changed, 74 insertions, 0 deletions
diff --git a/src/examples/_3_preemption.rs b/src/examples/_3_preemption.rs
new file mode 100644
index 00000000..b93ec086
--- /dev/null
+++ b/src/examples/_3_preemption.rs
@@ -0,0 +1,74 @@
+//! Two tasks running at different priorities with access to the same resource
+//!
+//! ```
+//! 
+//! #![deny(unsafe_code)]
+//! #![feature(const_fn)]
+//! #![feature(proc_macro)]
+//! #![no_std]
+//! 
+//! #[macro_use(task)]
+//! 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 task `SYS_TICK` has higher priority than `TIM2`
+//!         SYS_TICK: {
+//!             priority: 2,
+//!             resources: [COUNTER],
+//!         },
+//! 
+//!         TIM2: {
+//!             enabled: true,
+//!             priority: 1,
+//!             resources: [COUNTER],
+//!         },
+//!     },
+//! }
+//! 
+//! fn init(_p: init::Peripherals, _r: init::Resources) {
+//!     // ..
+//! }
+//! 
+//! fn idle() -> ! {
+//!     loop {
+//!         rtfm::wfi();
+//!     }
+//! }
+//! 
+//! task!(SYS_TICK, sys_tick);
+//! 
+//! fn sys_tick(_t: &mut Threshold, r: SYS_TICK::Resources) {
+//!     // ..
+//! 
+//!     // this task can't be preempted by `tim2` so it has direct access to the
+//!     // resource data
+//!     **r.COUNTER += 1;
+//! 
+//!     // ..
+//! }
+//! 
+//! task!(TIM2, tim2);
+//! 
+//! 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 data corruption or data loss
+//!     r.COUNTER.claim_mut(t, |counter, _t| { **counter += 1; });
+//! 
+//!     // ..
+//! }
+//! ```
+// Auto-generated. Do not modify.