task_local and lock_free analysis (take 1)

examples/local.rs

@@ -0,0 +1,79 @@
+//! examples/local.rs
+
+#![deny(unsafe_code)]
+#![deny(warnings)]
+#![no_main]
+#![no_std]
+
+use cortex_m_semihosting::{debug, hprintln};
+use lm3s6965::Interrupt;
+use panic_semihosting as _;
+
+#[rtfm::app(device = lm3s6965)]
+const APP: () = {
+    struct Resources {
+        // An early resource
+        #[init(0)]
+        shared: u32,
+
+        // A local (move), early resource
+        #[task_local]
+        #[init(1)]
+        l1: u32,
+
+        // An exclusive, early resource
+        #[lock_free]
+        #[init(1)]
+        e1: u32,
+
+        // A local (move), late resource
+        #[task_local]
+        l2: u32,
+
+        // An exclusive, late resource
+        #[lock_free]
+        e2: u32,
+    }
+
+    #[init]
+    fn init(_: init::Context) -> init::LateResources {
+        rtfm::pend(Interrupt::UART0);
+        rtfm::pend(Interrupt::UART1);
+        init::LateResources { e2: 2, l2: 2 }
+    }
+
+    // `shared` cannot be accessed from this context
+    // l1 ok (task_local)
+    // e2 ok (lock_free)
+    #[idle(resources =[l1, e2])]
+    fn idle(cx: idle::Context) -> ! {
+        hprintln!("IDLE:l1 = {}", cx.resources.l1).unwrap();
+        hprintln!("IDLE:e2 = {}", cx.resources.e2).unwrap();
+        debug::exit(debug::EXIT_SUCCESS);
+        loop {}
+    }
+
+    // `shared` can be accessed from this context
+    // l2 ok (task_local)
+    // e1 ok (lock_free)
+    #[task(priority = 1, binds = UART0, resources = [shared, l2, e1])]
+    fn uart0(cx: uart0::Context) {
+        let shared: &mut u32 = cx.resources.shared;
+        *shared += 1;
+        *cx.resources.e1 += 10;
+        hprintln!("UART0: shared = {}", shared).unwrap();
+        hprintln!("UART0:l2 = {}", cx.resources.l2).unwrap();
+        hprintln!("UART0:e1 = {}", cx.resources.e1).unwrap();
+    }
+
+    // `shared` can be accessed from this context
+    // e1 ok (lock_free)
+    #[task(priority = 1, binds = UART1, resources = [shared, e1])]
+    fn uart1(cx: uart1::Context) {
+        let shared: &mut u32 = cx.resources.shared;
+        *shared += 1;
+
+        hprintln!("UART1: shared = {}", shared).unwrap();
+        hprintln!("UART1:e1 = {}", cx.resources.e1).unwrap();
+    }
+};

examples/local_err.rs

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+//! examples/local_err.rs
+
+#![deny(unsafe_code)]
+#![deny(warnings)]
+#![no_main]
+#![no_std]
+
+// errors here, since we cannot bail compilation or generate stubs
+// run cargo expand, then you see the root of the problem...
+use cortex_m_semihosting::{debug, hprintln};
+use lm3s6965::Interrupt;
+use panic_semihosting as _;
+
+#[rtfm::app(device = lm3s6965)]
+const APP: () = {
+    struct Resources {
+        // An early resource
+        #[init(0)]
+        shared: u32,
+
+        // A local (move), early resource
+        #[task_local]
+        #[init(1)]
+        l1: u32,
+
+        // An exclusive, early resource
+        #[lock_free]
+        #[init(1)]
+        e1: u32,
+
+        // A local (move), late resource
+        #[task_local]
+        l2: u32,
+
+        // An exclusive, late resource
+        #[lock_free]
+        e2: u32,
+    }
+
+    #[init]
+    fn init(_: init::Context) -> init::LateResources {
+        rtfm::pend(Interrupt::UART0);
+        rtfm::pend(Interrupt::UART1);
+        init::LateResources { e2: 2, l2: 2 }
+    }
+
+    // `shared` cannot be accessed from this context
+    // l1 ok
+    // l2 rejeceted (not task_local)
+    // e2 ok
+    #[idle(resources =[l1, l2, e2])]
+    fn idle(cx: idle::Context) -> ! {
+        hprintln!("IDLE:l1 = {}", cx.resources.l1).unwrap();
+        hprintln!("IDLE:e2 = {}", cx.resources.e2).unwrap();
+        debug::exit(debug::EXIT_SUCCESS);
+        loop {}
+    }
+
+    // `shared` can be accessed from this context
+    // l2 rejected (not task_local)
+    // e1 rejected (not lock_free)
+    #[task(priority = 1, binds = UART0, resources = [shared, l2, e1])]
+    fn uart0(cx: uart0::Context) {
+        let shared: &mut u32 = cx.resources.shared;
+        *shared += 1;
+        *cx.resources.e1 += 10;
+        hprintln!("UART0: shared = {}", shared).unwrap();
+        hprintln!("UART0:l2 = {}", cx.resources.l2).unwrap();
+        hprintln!("UART0:e1 = {}", cx.resources.e1).unwrap();
+    }
+
+    // l2 rejected (not task_local)
+    #[task(priority = 2, binds = UART1, resources = [shared, l2, e1])]
+    fn uart1(cx: uart1::Context) {
+        let shared: &mut u32 = cx.resources.shared;
+        *shared += 1;
+
+        hprintln!("UART1: shared = {}", shared).unwrap();
+        hprintln!("UART1:l2 = {}", cx.resources.l2).unwrap();
+        hprintln!("UART1:e1 = {}", cx.resources.e1).unwrap();
+    }
+};

examples/local_minimal.rs

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+//! examples/local_minimal.rs
+#![deny(unsafe_code)]
+#![deny(warnings)]
+#![no_main]
+#![no_std]
+
+use cortex_m_semihosting::{debug, hprintln};
+use panic_semihosting as _;
+
+#[rtfm::app(device = lm3s6965)]
+const APP: () = {
+    struct Resources {
+        // A local (move), late resource
+        #[task_local]
+        l: u32,
+    }
+
+    #[init]
+    fn init(_: init::Context) -> init::LateResources {
+        init::LateResources { l: 42 }
+    }
+
+    // l is task_local
+    #[idle(resources =[l])]
+    fn idle(cx: idle::Context) -> ! {
+        hprintln!("IDLE:l = {}", cx.resources.l).unwrap();
+        debug::exit(debug::EXIT_SUCCESS);
+        loop {}
+    }
+};

examples/static.rs

@@ -0,0 +1,54 @@
+//! examples/late.rs
+
+#![deny(unsafe_code)]
+#![deny(warnings)]
+#![no_main]
+#![no_std]
+
+use cortex_m_semihosting::{debug, hprintln};
+use heapless::{
+    consts::*,
+    i,
+    spsc::{Consumer, Producer, Queue},
+};
+use lm3s6965::Interrupt;
+use panic_semihosting as _;
+
+#[rtfm::app(device = lm3s6965)]
+const APP: () = {
+    // Late resources
+    struct Resources {
+        p: Producer<'static, u32, U4>,
+        c: Consumer<'static, u32, U4>,
+    }
+
+    #[init]
+    fn init(_: init::Context) -> init::LateResources {
+        static mut Q: Queue<u32, U4> = Queue(i::Queue::new());
+
+        let (p, c) = Q.split();
+
+        // Initialization of late resources
+        init::LateResources { p, c }
+    }
+
+    #[idle(resources = [c])]
+    fn idle(c: idle::Context) -> ! {
+        loop {
+            if let Some(byte) = c.resources.c.dequeue() {
+                hprintln!("received message: {}", byte).unwrap();
+
+                debug::exit(debug::EXIT_SUCCESS);
+            } else {
+                rtfm::pend(Interrupt::UART0);
+            }
+        }
+    }
+
+    #[task(binds = UART0, resources = [p])]
+    fn uart0(c: uart0::Context) {
+        static mut KALLE: u32 = 0;
+        *KALLE += 1;
+        c.resources.p.enqueue(42).unwrap();
+    }
+};