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| author | bors[bot] <26634292+bors[bot]@users.noreply.github.com> | 2020-01-24 15:14:58 +0000 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2020-01-24 15:14:58 +0000 |
| commit | 03ac76a0a209f4af2baaf4bb56057b96a672e391 (patch) | |
| tree | f0980487592af1fdbb20c171409adaeab82e5f66 | |
| parent | 1e827e24d024e910b44f6cc6db278e4c66a77683 (diff) | |
| parent | b04103f6df712233b7659f2a845461f4db682e32 (diff) | |
Merge #295
295: docs: do not use Instant::now in #[init] r=korken89 a=japaric
Co-authored-by: Jorge Aparicio <jorge@japaric.io>
| -rw-r--r-- | examples/schedule.rs | 1 | ||||
| -rw-r--r-- | src/cyccnt.rs | 4 |
2 files changed, 5 insertions, 0 deletions
diff --git a/examples/schedule.rs b/examples/schedule.rs index 97818e3..a1c41ca 100644 --- a/examples/schedule.rs +++ b/examples/schedule.rs @@ -20,6 +20,7 @@ const APP: () = { cx.core.DWT.enable_cycle_counter(); // semantically, the monotonic timer is frozen at time "zero" during `init` + // NOTE do *not* call `Instant::now` in this context; it will return a nonsense value let now = cx.start; // the start time of the system hprintln!("init @ {:?}", now).unwrap(); diff --git a/src/cyccnt.rs b/src/cyccnt.rs index 338bbbe..6bc2ef0 100644 --- a/src/cyccnt.rs +++ b/src/cyccnt.rs @@ -30,6 +30,10 @@ pub struct Instant { impl Instant { /// Returns an instant corresponding to "now" + /// + /// *HEADS UP* this function can, and will, return nonsensical values if called within `init`. + /// Only use it in `idle` and tasks. In `init`, use the `init::Context.start` field, or the + /// `CYCCNT::zero` function, instead of this function pub fn now() -> Self { Instant { inner: DWT::get_cycle_count() as i32, |