[runtime] Fix Sleep Retries (#3594)

Author: patrick-ogrady

runtime/src/lib.rs

@@ -2484,7 +2484,7 @@ mod tests {
     /// `runtime_tasks_spawned` / `runtime_tasks_running`.
     fn test_metrics_spawn_attribute_cardinality<R: Runner>(runner: R)
     where
-        R::Context: Spawner + Metrics,
+        R::Context: Spawner + Metrics + Clock,
     {
         runner.start(|context| async move {
             const ROUNDS: u64 = 128;
@@ -2501,6 +2501,12 @@ mod tests {
                 assert_eq!(handle.await.expect("task failed"), expected as u64);
             }
 
+            // handle.await resolves when the task's output is ready, but
+            // the running-gauge decrement fires on task-struct drop which
+            // may lag slightly. Yield to the executor so it can run cleanup.
+            while count_running_tasks(&context, "deferred_verify") > 0 {
+                context.sleep(Duration::from_millis(10)).await;
+            }
             let buffer = context.encode();
 
             // Count occurrences of each runtime task metric for our label. If
@@ -2577,7 +2583,7 @@ mod tests {
     /// those entries nor create additional ones.
     fn test_metrics_spawn_scope_cardinality<R: Runner>(runner: R)
     where
-        R::Context: Spawner + Metrics,
+        R::Context: Spawner + Metrics + Clock,
     {
         runner.start(|context| async move {
             const ROUNDS: u64 = 128;
@@ -2596,6 +2602,12 @@ mod tests {
                 assert_eq!(handle.await.expect("task failed"), expected as u64);
             }
 
+            // handle.await resolves when the task's output is ready, but
+            // the running-gauge decrement fires on task-struct drop which
+            // may lag slightly. Yield to the executor so it can run cleanup.
+            while count_running_tasks(&context, "deferred_verify") > 0 {
+                context.sleep(Duration::from_millis(10)).await;
+            }
             let buffer = context.encode();
 
             let spawned_lines = buffer