Merge #176

176:  implement RFCs 147 and 155, fix #141, etc. r=japaric a=japaric

This PR:

- Implements RFC 147: "all functions must be safe"

- Implements RFC 155: "explicit Context parameter"

- Implements the pending breaking change #141: reject assign syntax in `init`
  (which was used to initialize late resources)

- Refactors code generation to make it more readable -- there are no more random
  identifiers in the output -- and align it with the book description of RTFM
  internals (see PR #175).

- Makes the framework hard depend on `core::mem::MaybeUninit` and thus will
  require nightly until that API is stabilized.

- Fixes a ceiling analysis bug where the priority of the system timer was not
  considered in the analysis (TODO backport this into the v0.4.x branch).

- Shrinks the size of all the internal queues by turning `AtomicUsize` indices
  into `AtomicU8`s.

- Removes the integration with `owned_singleton`.

closes #141
closes #147
closes #155

Additionally:

- This changes CI to push v0.5.x docs to
  https://japaric.github.io/rtfm5/book/en/ -- we need to do this because our
  official docs are hosted on https://japaric.github.io/cortex-m-rtfm and we
  need to keep them on v0.4.x until we release v0.5.0

- I propose that we use the master branch to develop the upcoming v0.5.0.

- I have created a branch v0.4.x for backports; new v0.4.x releases will come
  from that branch.

r? @korken89 @texitoi, sorry for doing all the impl work in a single commit --
I know that makes things harder to review for you.

Suggestions for compile-pass and compile-fail tests are welcome


Co-authored-by: Jorge Aparicio <jorge@japaric.io>

1 files changed, 67 insertions, 0 deletions

diff --git a/examples/pool.rs b/examples/pool.rs
new file mode 100644
index 0000000..0b594b1
--- /dev/null
+++ b/examples/pool.rs
@@ -0,0 +1,67 @@
+//! examples/pool.rs
+
+#![deny(unsafe_code)]
+#![deny(warnings)]
+#![no_main]
+#![no_std]
+
+extern crate panic_semihosting;
+
+use cortex_m_semihosting::{debug, hprintln};
+use heapless::{
+    pool,
+    pool::singleton::{Box, Pool},
+};
+use lm3s6965::Interrupt;
+use rtfm::app;
+
+// Declare a pool of 128-byte memory blocks
+pool!(P: [u8; 128]);
+
+#[app(device = lm3s6965)]
+const APP: () = {
+    #[init]
+    fn init(_: init::Context) {
+        static mut MEMORY: [u8; 512] = [0; 512];
+
+        // Increase the capacity of the memory pool by ~4
+        P::grow(MEMORY);
+
+        rtfm::pend(Interrupt::I2C0);
+    }
+
+    #[interrupt(priority = 2, spawn = [foo, bar])]
+    fn I2C0(c: I2C0::Context) {
+        // claim a memory block, leave it uninitialized and ..
+        let x = P::alloc().unwrap().freeze();
+
+        // .. send it to the `foo` task
+        c.spawn.foo(x).ok().unwrap();
+
+        // send another block to the task `bar`
+        c.spawn.bar(P::alloc().unwrap().freeze()).ok().unwrap();
+    }
+
+    #[task]
+    fn foo(_: foo::Context, x: Box<P>) {
+        hprintln!("foo({:?})", x.as_ptr()).unwrap();
+
+        // explicitly return the block to the pool
+        drop(x);
+
+        debug::exit(debug::EXIT_SUCCESS);
+    }
+
+    #[task(priority = 2)]
+    fn bar(_: bar::Context, x: Box<P>) {
+        hprintln!("bar({:?})", x.as_ptr()).unwrap();
+
+        // this is done automatically so we can omit the call to `drop`
+        // drop(x);
+    }
+
+    extern "C" {
+        fn UART0();
+        fn UART1();
+    }
+};