Do not sleep if at least one task was woken up

Author: Disasm

async-cortex-m/src/executor.rs

@@ -66,8 +66,11 @@ impl Executor {
         let waker =
             unsafe { Waker::from_raw(RawWaker::new(&ready as *const _ as *const _, &VTABLE)) };
         let val = loop {
+            let mut task_woken = false;
+
             // advance the main task
             if ready.load(Ordering::Acquire) {
+                task_woken = true;
                 ready.store(false, Ordering::Release);
 
                 let mut cx = Context::from_waker(&waker);
@@ -88,6 +91,7 @@ impl Executor {
                 // "oneshot": they'll issue a `wake` and then disable themselves to not run again
                 // until the woken task has made more work
                 if task.ready.load(Ordering::Acquire) {
+                    task_woken = true;
 
                     // we are about to service the task so switch the `ready` flag to `false`
                     task.ready.store(false, Ordering::Release);
@@ -109,6 +113,11 @@ impl Executor {
                 }
             }
 
+            if task_woken {
+                // If at least one task was woken up, do not sleep, try again
+                continue;
+            }
+
             // try to sleep; this will be a no-op if any of the previous tasks generated a SEV or an
             // interrupt ran (regardless of whether it generated a wake-up or not)
             asm::wfe();