lilos-watch: initial draft.

Cargo.toml

@@ -6,6 +6,7 @@ members = [
     "handoff",
     "semaphore",
     "rwlock",
+    "watch",
     "examples/*/*",
     "testsuite",
     "testsuite/stm32f3",
@@ -29,6 +30,7 @@ lilos-testsuite = { path = "testsuite" }
 lilos-handoff = { path = "handoff" }
 lilos-semaphore = { path = "semaphore" }
 lilos-rwlock = { path = "rwlock" }
+lilos-watch = { path = "watch" }
 
 # External
 cfg-if = "1.0.0"

build-all.sh

@@ -20,7 +20,7 @@ for k in ${!MODES[@]}; do
     popd > /dev/null
 done
 
-DIRS="handoff semaphore rwlock list testsuite/stm32f4 testsuite/stm32g0 testsuite/stm32f3 testsuite/lm3s6965 examples/*/*/"
+DIRS="handoff semaphore rwlock list watch testsuite/stm32f4 testsuite/stm32g0 testsuite/stm32f3 testsuite/lm3s6965 examples/*/*/"
 
 for d in $DIRS; do
     if [[ $d == *memory.x ]]; then

clippy-all.sh

@@ -2,7 +2,7 @@
 
 set -euo pipefail
 
-DIRS="os list handoff semaphore rwlock testsuite/stm32f4 testsuite/stm32g0 testsuite/stm32f3 examples/*/*/"
+DIRS="os list handoff semaphore rwlock watch testsuite/stm32f4 testsuite/stm32g0 testsuite/stm32f3 examples/*/*/"
 
 for d in $DIRS; do
     echo "---- clipping in $d"

doc-all.sh

@@ -2,7 +2,7 @@
 
 set -euo pipefail
 
-DIRS="os list handoff semaphore rwlock"
+DIRS="os list handoff semaphore rwlock watch"
 
 for d in $DIRS; do
     echo "---- testing doc generation in $d"

msrv-all.sh

@@ -4,7 +4,7 @@ set -euo pipefail
 
 jq --version
 
-DIRS="os list handoff semaphore rwlock testsuite/stm32f4 testsuite/stm32g0 testsuite/stm32f3 examples/*/*/"
+DIRS="os list handoff semaphore rwlock watch testsuite/stm32f4 testsuite/stm32g0 testsuite/stm32f3 examples/*/*/"
 
 for d in $DIRS; do
     pushd $d > /dev/null

testsuite/Cargo.toml

@@ -11,10 +11,11 @@ repository.workspace = true
 rust-version.workspace = true
 
 [features]
-default = ["handoff", "semaphore", "rwlock"]
+default = ["handoff", "semaphore", "rwlock", "watch"]
 handoff = ["dep:lilos-handoff"]
 semaphore = ["dep:lilos-semaphore"]
 rwlock = ["dep:lilos-rwlock"]
+watch = ["dep:lilos-watch"]
 
 [package.metadata.docs.rs]
 default-target = "thumbv7em-none-eabihf"
@@ -30,6 +31,7 @@ lilos-semaphore = { workspace = true, optional = true }
 lilos-rwlock = { workspace = true, optional = true }
 panic-semihosting.workspace = true
 lilos-list.workspace = true
+lilos-watch = { workspace = true, optional = true }
 
 [lib]
 test = false

testsuite/src/lib.rs

@@ -17,6 +17,8 @@ mod handoff;
 mod semaphore;
 #[cfg(feature = "rwlock")]
 mod rwlock;
+#[cfg(feature = "watch")]
+mod watch;
 
 use core::convert::Infallible;
 use core::pin::pin;
@@ -162,6 +164,11 @@ async fn task_coordinator() -> Infallible {
             rwlock::test_blocking,
             #[cfg(feature = "rwlock")]
             rwlock::test_fairness,
+
+            #[cfg(feature = "watch")]
+            watch::test_receive_only,
+            #[cfg(feature = "watch")]
+            watch::test_send_receive,
         }
     };
 

testsuite/src/watch.rs

@@ -0,0 +1,40 @@
+use core::pin::pin;
+
+use lilos_watch::Watch;
+
+use crate::{poll_and_assert_not_ready, poll_and_assert_ready};
+
+pub async fn test_receive_only() {
+    let w = Watch::new(123_u32);
+
+    let mut receiver = w.subscribe();
+
+    receiver.glimpse(|&value| assert_eq!(value, 123_u32));
+
+    {
+        let mut change_fut = pin!(receiver.changed());
+        poll_and_assert_not_ready!(change_fut.as_mut());
+        poll_and_assert_not_ready!(change_fut.as_mut());
+    }
+
+    receiver.mark_as_unseen();
+
+    {
+        let mut change_fut = pin!(receiver.changed());
+        poll_and_assert_ready!(change_fut.as_mut());
+    }
+}
+
+pub async fn test_send_receive() {
+    let w = Watch::new(123_u32);
+
+    let sender = w.sender();
+    let mut receiver = w.subscribe();
+
+    poll_and_assert_not_ready!(pin!(receiver.changed()));
+
+    sender.send(456_u32);
+
+    poll_and_assert_ready!(pin!(receiver.changed()));
+    receiver.glimpse(|&value| assert_eq!(value, 456_u32));
+}

watch/.cargo/config.toml

@@ -0,0 +1,2 @@
+[build]
+target = "thumbv7em-none-eabihf"

watch/Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "lilos-watch"
+version = "0.1.0"
+edition.workspace = true
+license.workspace = true
+repository.workspace = true
+rust-version.workspace = true
+
+[dependencies]
+lilos.workspace = true
+
+[lib]
+test = false
+bench = false