Skip scheduling recent failed tasks if an earlier task is already InP…

…rogress (#2934)

Fixes: flutter/flutter#110716

app_dart/lib/src/service/scheduler/policy.dart

@@ -56,6 +56,11 @@ class BatchPolicy implements SchedulerPolicy {
     required DatastoreService datastore,
   }) async {
     final List<Task> recentTasks = await datastore.queryRecentTasksByName(name: task.name!).toList();
+    // Skip scheduling if there is already a running task.
+    if (recentTasks.any((Task task) => task.status == Task.statusInProgress)) {
+      return null;
+    }
+
     // Ensure task isn't considered in recentTasks
     recentTasks.removeWhere((Task t) => t.commitKey == task.commitKey);
     if (recentTasks.length < kBatchSize) {

app_dart/test/service/scheduler/policy_test.dart

@@ -65,6 +65,15 @@ void main() {
       generateTask(1, status: Task.statusSucceeded),
     ];
 
+    final List<Task> failedWithRunning = <Task>[
+      generateTask(6),
+      generateTask(5),
+      generateTask(4),
+      generateTask(3, status: Task.statusFailed),
+      generateTask(2, status: Task.statusInProgress),
+      generateTask(1),
+    ];
+
     test('triggers if less tasks than batch size', () async {
       db.addOnQuery<Task>((Iterable<Task> results) => allPending);
       expect(
@@ -89,6 +98,14 @@ void main() {
       );
     });
 
+    test('does not trigger on recent failures if there is already a running task', () async {
+      db.addOnQuery<Task>((Iterable<Task> results) => failedWithRunning);
+      expect(
+        await policy.triggerPriority(task: generateTask(7), datastore: datastore),
+        isNull,
+      );
+    });
+
     test('does not trigger when a test was recently scheduled', () async {
       db.addOnQuery<Task>((Iterable<Task> results) => latestFinishedButRestPending);
       expect(await policy.triggerPriority(task: generateTask(7), datastore: datastore), isNull);