From 9081694d2d8c462f1bea87696c33cd8596d02c1a Mon Sep 17 00:00:00 2001
From: keyonghan <54558023+keyonghan@users.noreply.github.com>
Date: Fri, 14 Jul 2023 15:13:52 -0700
Subject: [PATCH] Skip scheduling recent failed tasks if an earlier task is
 already InProgress (#2934)

Fixes: https://github.com/flutter/flutter/issues/110716
---
 app_dart/lib/src/service/scheduler/policy.dart  |  5 +++++
 .../test/service/scheduler/policy_test.dart     | 17 +++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/app_dart/lib/src/service/scheduler/policy.dart b/app_dart/lib/src/service/scheduler/policy.dart
index c0da468e3..36158339c 100644
--- a/app_dart/lib/src/service/scheduler/policy.dart
+++ b/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) {
diff --git a/app_dart/test/service/scheduler/policy_test.dart b/app_dart/test/service/scheduler/policy_test.dart
index 4cd169a56..275fd16ea 100644
--- a/app_dart/test/service/scheduler/policy_test.dart
+++ b/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);