api test (mostly hard coded)

examples/lockall.rs

@@ -0,0 +1,73 @@
+//! examples/lock.rs
+
+// #![deny(unsafe_code)]
+// #![deny(warnings)]
+#![no_main]
+#![no_std]
+
+use panic_semihosting as _;
+
+#[rtic::app(device = lm3s6965, dispatchers = [GPIOA])]
+mod app {
+    use cortex_m_semihosting::{debug, hprintln};
+
+    #[shared]
+    struct Shared {
+        a: u32,
+        b: i64,
+    }
+
+    #[local]
+    struct Local {}
+
+    #[init]
+    fn init(_: init::Context) -> (Shared, Local, init::Monotonics) {
+        foo::spawn().unwrap();
+
+        (Shared { a: 1, b: 2 }, Local {}, init::Monotonics())
+    }
+
+    // when omitted priority is assumed to be `1`
+    #[task(shared = [a, b])]
+    fn foo(mut c: foo::Context) {
+        static mut X: Option<&'static mut u32> = None;
+        static mut Y: u32 = 0;
+        let _ = hprintln!("before lock");
+        c.shared.lock(|s| {
+            let _ = hprintln!("in lock");
+            let _ = hprintln!("here {}, {}", s.a, s.b);
+            *s.a += 1;
+
+            // soundness check
+            // c.shared.lock(|s| {}); // borrow error
+            // c.shared.a.lock(|s| {}); // borrow error
+
+            unsafe {
+                X = Some(&mut Y);
+                // X = Some(s.a); // lifetime issue
+                // X = Some(&mut *s.a); // lifetime issue
+                // X = Some(&'static mut *s.a); // not rust
+            }
+            let _ = hprintln!("here {}, {}", s.a, s.b);
+        });
+        // the lower priority task requires a critical section to access the data
+        // c.shared.shared.lock(|shared| {
+        //     // data can only be modified within this critical section (closure)
+        //     *shared += 1;
+
+        //     // bar will *not* run right now due to the critical section
+        //     bar::spawn().unwrap();
+
+        //     hprintln!("B - shared = {}", *shared).unwrap();
+
+        //     // baz does not contend for `shared` so it's allowed to run now
+        //     baz::spawn().unwrap();
+        // });
+
+        // // critical section is over: bar can now start
+
+        // hprintln!("E").unwrap();
+
+        debug::exit(debug::EXIT_SUCCESS); // Exit QEMU simulator
+    }
+}