Changelog fragment

async/every.go

@@ -29,3 +29,24 @@ func RunEvery(ctx context.Context, period time.Duration, f func()) {
 		}
 	}()
 }
+
+// RunEveryDynamic runs the provided command periodically with a dynamic interval.
+// The interval is determined by calling the intervalFunc before each execution.
+// It runs in a goroutine, and can be cancelled by finishing the supplied context.
+func RunEveryDynamic(ctx context.Context, intervalFunc func() time.Duration, f func()) {
+	go func() {
+		for {
+			// Get the next interval duration
+			interval := intervalFunc()
+			timer := time.NewTimer(interval)
+
+			select {
+			case <-timer.C:
+				f()
+			case <-ctx.Done():
+				timer.Stop()
+				return
+			}
+		}
+	}()
+}

async/every_test.go

@@ -38,3 +38,51 @@ func TestEveryRuns(t *testing.T) {
 		t.Error("Counter incremented after stop")
 	}
 }
+
+func TestEveryDynamicRuns(t *testing.T) {
+	ctx, cancel := context.WithCancel(t.Context())
+
+	i := int32(0)
+	intervalCount := int32(0)
+
+	// Start with 50ms intervals, then increase to 100ms after 2 calls
+	async.RunEveryDynamic(ctx, func() time.Duration {
+		count := atomic.LoadInt32(&intervalCount)
+		atomic.AddInt32(&intervalCount, 1)
+		if count < 2 {
+			return 50 * time.Millisecond
+		}
+		return 100 * time.Millisecond
+	}, func() {
+		atomic.AddInt32(&i, 1)
+	})
+
+	// After 150ms, should have run at least 2 times (at 50ms and 100ms)
+	time.Sleep(150 * time.Millisecond)
+	count1 := atomic.LoadInt32(&i)
+	if count1 < 2 {
+		t.Errorf("Expected at least 2 runs after 150ms, got %d", count1)
+	}
+
+	// After another 150ms (total 300ms), should have run at least 3 times
+	// (50ms, 100ms, 150ms, 250ms)
+	time.Sleep(150 * time.Millisecond)
+	count2 := atomic.LoadInt32(&i)
+	if count2 < 3 {
+		t.Errorf("Expected at least 3 runs after 300ms, got %d", count2)
+	}
+
+	cancel()
+
+	// Sleep for a bit to let the cancel take place.
+	time.Sleep(100 * time.Millisecond)
+
+	last := atomic.LoadInt32(&i)
+
+	// Sleep for a bit and ensure the value has not increased.
+	time.Sleep(200 * time.Millisecond)
+
+	if atomic.LoadInt32(&i) != last {
+		t.Error("Counter incremented after stop")
+	}
+}

changelog/pvl-async-dynamic-run-every.md

@@ -0,0 +1,3 @@
+### Added
+
+- async: Added a method for periodic execution with dynamic intervals. This is useful for a future progressive slot schedule.