IndexedDB: Add a finch trial for setting Blink tasks to high priority

Bug: 984374
Change-Id: I47829925197a08fb58469418a7f392d350dd52ca
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1652747
Commit-Queue: Chase Phillips <cmp@chromium.org>
Reviewed-by: Alexander Timin <altimin@chromium.org>
Reviewed-by: Daniel Murphy <dmurph@chromium.org>
Cr-Commit-Position: refs/heads/master@{#678882}

third_party/blink/renderer/platform/scheduler/common/features.h

@@ -174,6 +174,10 @@ const base::Feature kBlinkSchedulerDisableAntiStarvationForPriorities{
     "BlinkSchedulerDisableAntiStarvationForPriorities",
     base::FEATURE_DISABLED_BY_DEFAULT};
 
+// Enable setting high priority database task type from field trial parameters.
+const base::Feature kHighPriorityDatabaseTaskType{
+    "HighPriorityDatabaseTaskType", base::FEATURE_DISABLED_BY_DEFAULT};
+
 }  // namespace scheduler
 }  // namespace blink
 

third_party/blink/renderer/platform/scheduler/main_thread/frame_scheduler_impl.cc

@@ -398,7 +398,7 @@ base::Optional<QueueTraits> FrameSchedulerImpl::CreateQueueTraitsForTaskType(
   // TODO(haraken): Optimize the mapping from TaskTypes to task runners.
   switch (type) {
     // kInternalContentCapture uses BestEffortTaskQueue and is handled
-    // sparately.
+    // separately.
     case TaskType::kInternalContentCapture:
     case TaskType::kJavascriptTimer:
       return ThrottleableTaskQueueTraits();
@@ -445,7 +445,6 @@ base::Optional<QueueTraits> FrameSchedulerImpl::CreateQueueTraitsForTaskType(
     // Media events should not be deferred to ensure that media playback is
     // smooth.
     case TaskType::kMediaElementEvent:
-    case TaskType::kDatabaseAccess:
     case TaskType::kInternalWebCrypto:
     case TaskType::kInternalMedia:
     case TaskType::kInternalMediaRealTime:
@@ -453,6 +452,11 @@ base::Optional<QueueTraits> FrameSchedulerImpl::CreateQueueTraitsForTaskType(
     case TaskType::kInternalIntersectionObserver:
     case TaskType::kInternalContinueScriptLoading:
       return PausableTaskQueueTraits();
+    case TaskType::kDatabaseAccess:
+      if (base::FeatureList::IsEnabled(kHighPriorityDatabaseTaskType))
+        return PausableTaskQueueTraits().SetIsHighPriority(true);
+      else
+        return PausableTaskQueueTraits();
     case TaskType::kInternalFreezableIPC:
       return FreezableTaskQueueTraits();
     case TaskType::kInternalIPC:

third_party/blink/renderer/platform/scheduler/main_thread/frame_scheduler_impl_unittest.cc

@@ -282,6 +282,11 @@ void IncrementCounter(int* counter) {
   ++*counter;
 }
 
+void ExpectAndIncrementCounter(int expected, int* actual) {
+  EXPECT_EQ(expected, *actual);
+  IncrementCounter(actual);
+}
+
 void RecordQueueName(String name, Vector<String>* tasks) {
   tasks->push_back(std::move(name));
 }
@@ -1905,6 +1910,86 @@ TEST_F(ThrottleableOnlyTaskTypesTest, QueueTraitsFromFieldTrialParams) {
           true));
 }
 
+class FrameSchedulerImplDatabaseAccessWithoutHighPriority
+    : public FrameSchedulerImplTest {
+ public:
+  FrameSchedulerImplDatabaseAccessWithoutHighPriority()
+      : FrameSchedulerImplTest({}, {kHighPriorityDatabaseTaskType}) {}
+};
+
+TEST_F(FrameSchedulerImplDatabaseAccessWithoutHighPriority, QueueTraits) {
+  // These tests will start to fail if the default task queues or queue traits
+  // change for these task types.
+
+  int counter = 0;
+
+  auto loading_queue = GetTaskQueue(TaskType::kInternalContinueScriptLoading);
+  EXPECT_EQ(loading_queue->GetQueuePriority(),
+            TaskQueue::QueuePriority::kVeryHighPriority);
+  loading_queue->task_runner()->PostTask(
+      FROM_HERE, base::BindOnce(&ExpectAndIncrementCounter, 0,
+                                base::Unretained(&counter)));
+
+  auto da_queue = GetTaskQueue(TaskType::kDatabaseAccess);
+  EXPECT_EQ(da_queue->GetQueueTraits().is_high_priority, false);
+  EXPECT_EQ(da_queue->GetQueuePriority(),
+            TaskQueue::QueuePriority::kNormalPriority);
+  da_queue->task_runner()->PostTask(
+      FROM_HERE, base::BindOnce(&ExpectAndIncrementCounter, 1,
+                                base::Unretained(&counter)));
+
+  auto content_queue = GetTaskQueue(TaskType::kInternalContentCapture);
+  EXPECT_EQ(content_queue->GetQueuePriority(),
+            TaskQueue::QueuePriority::kBestEffortPriority);
+  content_queue->task_runner()->PostTask(
+      FROM_HERE, base::BindOnce(&ExpectAndIncrementCounter, 2,
+                                base::Unretained(&counter)));
+
+  EXPECT_EQ(0, counter);
+  base::RunLoop().RunUntilIdle();
+  EXPECT_EQ(3, counter);
+}
+
+class FrameSchedulerImplDatabaseAccessWithHighPriority
+    : public FrameSchedulerImplTest {
+ public:
+  FrameSchedulerImplDatabaseAccessWithHighPriority()
+      : FrameSchedulerImplTest({kHighPriorityDatabaseTaskType}, {}) {}
+};
+
+TEST_F(FrameSchedulerImplDatabaseAccessWithHighPriority, QueueTraits) {
+  // These tests will start to fail if the default task queues or queue traits
+  // change for these task types.
+
+  int counter = 0;
+
+  auto loading_queue = GetTaskQueue(TaskType::kInternalContinueScriptLoading);
+  EXPECT_EQ(loading_queue->GetQueuePriority(),
+            TaskQueue::QueuePriority::kVeryHighPriority);
+  loading_queue->task_runner()->PostTask(
+      FROM_HERE, base::BindOnce(&ExpectAndIncrementCounter, 0,
+                                base::Unretained(&counter)));
+
+  auto da_queue = GetTaskQueue(TaskType::kDatabaseAccess);
+  EXPECT_EQ(da_queue->GetQueueTraits().is_high_priority, true);
+  EXPECT_EQ(da_queue->GetQueuePriority(),
+            TaskQueue::QueuePriority::kHighPriority);
+  da_queue->task_runner()->PostTask(
+      FROM_HERE, base::BindOnce(&ExpectAndIncrementCounter, 1,
+                                base::Unretained(&counter)));
+
+  auto pausable_queue = PausableTaskQueue();
+  EXPECT_EQ(pausable_queue->GetQueuePriority(),
+            TaskQueue::QueuePriority::kNormalPriority);
+  pausable_queue->task_runner()->PostTask(
+      FROM_HERE, base::BindOnce(&ExpectAndIncrementCounter, 2,
+                                base::Unretained(&counter)));
+
+  EXPECT_EQ(0, counter);
+  base::RunLoop().RunUntilIdle();
+  EXPECT_EQ(3, counter);
+}
+
 TEST_F(FrameSchedulerImplTest, ContentCaptureHasIdleTaskQueue) {
   auto task_queue = GetTaskQueue(TaskType::kInternalContentCapture);
 

third_party/blink/renderer/platform/scheduler/main_thread/frame_task_queue_controller.cc

@@ -129,19 +129,28 @@ void FrameTaskQueueController::CreateNonLoadingTaskQueue(
   // |main_thread_scheduler_impl_| can be null in unit tests.
   DCHECK(main_thread_scheduler_impl_);
 
+  MainThreadTaskQueue::QueueCreationParams queue_creation_params(
+      QueueTypeFromQueueTraits(queue_traits));
+
+  queue_creation_params =
+      queue_creation_params
+          .SetQueueTraits(queue_traits)
+          // Freeze when keep active is currently only set for the
+          // throttleable queue.
+          // TODO(altimin): Figure out how to set this for new queues.
+          // Investigate which tasks must be kept alive, and if possible
+          // move them to an unfreezable queue and remove this override and
+          // the page scheduler KeepActive freezing override.
+          .SetFreezeWhenKeepActive(queue_traits.can_be_throttled)
+          .SetFrameScheduler(frame_scheduler_impl_);
+
+  if (queue_traits.is_high_priority) {
+    queue_creation_params = queue_creation_params.SetFixedPriority(
+        TaskQueue::QueuePriority::kHighPriority);
+  }
+
   scoped_refptr<MainThreadTaskQueue> task_queue =
-      main_thread_scheduler_impl_->NewTaskQueue(
-          MainThreadTaskQueue::QueueCreationParams(
-              QueueTypeFromQueueTraits(queue_traits))
-              .SetQueueTraits(queue_traits)
-              // Freeze when keep active is currently only set for the
-              // throttleable queue.
-              // TODO(altimin): Figure out how to set this for new queues.
-              // Investigate which tasks must be kept alive, and if possible
-              // move them to an unfreezable queue and remove this override and
-              // the page scheduler KeepActive freezing override.
-              .SetFreezeWhenKeepActive(queue_traits.can_be_throttled)
-              .SetFrameScheduler(frame_scheduler_impl_));
+      main_thread_scheduler_impl_->NewTaskQueue(queue_creation_params);
   TaskQueueCreated(task_queue);
   non_loading_task_queues_.insert(queue_traits.Key(), task_queue);
 }

third_party/blink/renderer/platform/scheduler/main_thread/main_thread_task_queue.h

@@ -104,7 +104,8 @@ class PLATFORM_EXPORT MainThreadTaskQueue
           can_be_paused(false),
           can_be_frozen(false),
           can_run_in_background(true),
-          should_use_virtual_time(true) {}
+          should_use_virtual_time(true),
+          is_high_priority(false) {}
 
     QueueTraits(const QueueTraits&) = default;
 
@@ -138,13 +139,19 @@ class PLATFORM_EXPORT MainThreadTaskQueue
       return *this;
     }
 
+    QueueTraits SetIsHighPriority(bool value) {
+      is_high_priority = value;
+      return *this;
+    }
+
     bool operator==(const QueueTraits& other) const {
       return can_be_deferred == other.can_be_deferred &&
              can_be_throttled == other.can_be_throttled &&
              can_be_paused == other.can_be_paused &&
              can_be_frozen == other.can_be_frozen &&
              can_run_in_background == other.can_run_in_background &&
-             should_use_virtual_time == other.should_use_virtual_time;
+             should_use_virtual_time == other.should_use_virtual_time &&
+             is_high_priority == other.is_high_priority;
     }
 
     // Return a key suitable for WTF::HashMap.
@@ -157,6 +164,7 @@ class PLATFORM_EXPORT MainThreadTaskQueue
       key |= can_be_frozen << 4;
       key |= can_run_in_background << 5;
       key |= should_use_virtual_time << 6;
+      key |= is_high_priority << 7;
       return key;
     }
 
@@ -166,6 +174,7 @@ class PLATFORM_EXPORT MainThreadTaskQueue
     bool can_be_frozen : 1;
     bool can_run_in_background : 1;
     bool should_use_virtual_time : 1;
+    bool is_high_priority : 1;
   };
 
   struct QueueCreationParams {