From ec96395d084d5edc8be25ddaea8547e2ebd447a6 Mon Sep 17 00:00:00 2001 From: Dániel Buga Date: Mon, 9 Dec 2024 08:43:57 +0100 Subject: Prevent task from respawning while in the timer queue --- embassy-time-queue-driver/src/lib.rs | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'embassy-time-queue-driver/src/lib.rs') diff --git a/embassy-time-queue-driver/src/lib.rs b/embassy-time-queue-driver/src/lib.rs index 0c78921ed..2d5fd449a 100644 --- a/embassy-time-queue-driver/src/lib.rs +++ b/embassy-time-queue-driver/src/lib.rs @@ -73,6 +73,20 @@ extern "Rust" { /// Schedule the given waker to be woken at `at`. pub fn schedule_wake(at: u64, waker: &Waker) { + #[cfg(feature = "integrated-timers")] + { + use embassy_executor::raw::task_from_waker; + use embassy_executor::raw::timer_queue::TimerEnqueueOperation; + // The very first thing we must do, before we even access the timer queue, is to + // mark the task a TIMER_QUEUED. This ensures that the task that is being scheduled + // can not be respawn while we are accessing the timer queue. + let task = task_from_waker(waker); + if unsafe { task.timer_enqueue() } == TimerEnqueueOperation::Ignore { + // We are not allowed to enqueue the task in the timer queue. This is because the + // task is not spawned, and so it makes no sense to schedule it. + return; + } + } unsafe { _embassy_time_schedule_wake(at, waker) } } -- cgit