Fix mono delay (#843)

* rtic-time: Compenstate for timer uncertainty

* Update changelog and incorrect cargo.lock in an example

* Fix Monotonic impls

* Fix tests

* Fix other monotonics, again

* Update changelog

* Fix example

* Fix DelayUs and DelayMs impls

* Minor coding style fix in u64 conversions

* Fix all changelogs

* Fix changelog

* Fix blocking DelayUs

* Minor monotonic rework

* Add delay precision test

* Add more tests

* Add rust-version tags to Cargo.toml

* Fix imxrt, rp2040 and systick timer

* Fix more monotonics

* Fix systick monotonic

* Some reverts

* Fix imxrt

* Fix nrf

* Fix rp2040

* Fix stm32

* Fix systick

* Fix rtic-time tests

* Bump to e-h.rc2

* Apply e-h.rc2 fixes to rtic-time

* Apply fixes from arbiter

* Fix clippy warning

* Minor beautification

* Revert previous changes

* Fix variable name

* Add blocking tests, but disable them by default

1 files changed, 10 insertions, 8 deletions

diff --git a/rtic-time/tests/timer_queue.rs b/rtic-time/tests/timer_queue.rs
index 9ad71757..8bae3853 100644
--- a/rtic-time/tests/timer_queue.rs
+++ b/rtic-time/tests/timer_queue.rs
@@ -17,7 +17,7 @@ static NOW: Mutex<Option<Instant>> = Mutex::new(None);
 pub struct Duration(u64);
 
 impl Duration {
-    pub fn from_ticks(millis: u64) -> Self {
+    pub const fn from_ticks(millis: u64) -> Self {
         Self(millis)
     }
 
@@ -161,6 +161,7 @@ impl TestMono {
 
 impl Monotonic for TestMono {
     const ZERO: Self::Instant = Instant::ZERO;
+    const TICK_PERIOD: Self::Duration = Duration::from_ticks(1);
 
     type Instant = Instant;
 
@@ -210,7 +211,8 @@ fn timer_queue() {
             let elapsed = start.elapsed().as_ticks();
             println!("{total_millis} ticks delay reached after {elapsed} ticks");
 
-            if elapsed != total_millis {
+            // Expect a delay of one longer, to compensate for timer uncertainty
+            if elapsed != total_millis + 1 {
                 panic!(
                     "{total_millis} ticks delay was not on time ({elapsed} ticks passed instead)"
                 );
@@ -263,25 +265,25 @@ fn timer_queue() {
 
         if Instant::now() == 0.into() {
             // First, we want to be waiting for our 300 tick delay
-            assert_eq!(TestMono::compare(), Some(300.into()));
+            assert_eq!(TestMono::compare(), Some(301.into()));
         }
 
         if Instant::now() == 100.into() {
             // After 100 ticks, we enqueue a new delay that is supposed to last
             // until the 200-tick-mark
-            assert_eq!(TestMono::compare(), Some(200.into()));
+            assert_eq!(TestMono::compare(), Some(201.into()));
         }
 
-        if Instant::now() == 200.into() {
+        if Instant::now() == 201.into() {
             // After 200 ticks, we dequeue the 200-tick-mark delay and
             // requeue the 300 tick delay
-            assert_eq!(TestMono::compare(), Some(300.into()));
+            assert_eq!(TestMono::compare(), Some(301.into()));
         }
 
-        if Instant::now() == 300.into() {
+        if Instant::now() == 301.into() {
             // After 300 ticks, we dequeue the 300-tick-mark delay and
             // go to the 400 tick delay that is already enqueued
-            assert_eq!(TestMono::compare(), Some(400.into()));
+            assert_eq!(TestMono::compare(), Some(401.into()));
         }
     }