[PM] Add priority and reason to ExecutionContext and its observer

Bug: 1077217
Change-Id: Ie0081edc73c8b8ed0669c0aacaad9ccbb2ead003
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2490800Reviewed-by: Chris Hamilton <chrisha@chromium.org>
Commit-Queue: Patrick Monette <pmonette@chromium.org>
Cr-Commit-Position: refs/heads/master@{#820317}

components/performance_manager/execution_context/execution_context_impl.cc

@@ -68,6 +68,13 @@ class ExecutionContextImpl : public ExecutionContext,
     return node_->process_node();
   }
 
+  // Returns the current priority of the execution context, and the reason for
+  // the execution context having that particular priority.
+  const PriorityAndReason& GetPriorityAndReason() const override {
+    DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
+    return node_->priority_and_reason();
+  }
+
   const FrameNode* GetFrameNode() const override {
     DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
     if (std::is_same<FrameNodeImpl, NodeImplType>::value)

components/performance_manager/execution_context/execution_context_registry_impl.cc

@@ -52,6 +52,12 @@ class DummyExecutionContextForLookup : public ExecutionContext {
     return nullptr;
   }
 
+  const PriorityAndReason& GetPriorityAndReason() const override {
+    NOTREACHED();
+    static const PriorityAndReason kPriorityAndReason;
+    return kPriorityAndReason;
+  }
+
   const FrameNode* GetFrameNode() const override {
     NOTREACHED();
     return nullptr;
@@ -149,6 +155,21 @@ ExecutionContextRegistryImpl::GetExecutionContextForWorkerNode(
   return GetOrCreateExecutionContextForWorkerNode(worker_node);
 }
 
+void ExecutionContextRegistryImpl::OnPassedToGraph(Graph* graph) {
+  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
+  DCHECK(graph->IsEmpty());
+  graph->RegisterObject(this);
+  graph->AddFrameNodeObserver(this);
+  graph->AddWorkerNodeObserver(this);
+}
+
+void ExecutionContextRegistryImpl::OnTakenFromGraph(Graph* graph) {
+  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
+  graph->RemoveWorkerNodeObserver(this);
+  graph->RemoveFrameNodeObserver(this);
+  graph->UnregisterObject(this);
+}
+
 void ExecutionContextRegistryImpl::OnFrameNodeAdded(
     const FrameNode* frame_node) {
   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
@@ -171,19 +192,14 @@ void ExecutionContextRegistryImpl::OnBeforeFrameNodeRemoved(
   DCHECK_EQ(1u, erased);
 }
 
-void ExecutionContextRegistryImpl::OnPassedToGraph(Graph* graph) {
+void ExecutionContextRegistryImpl::OnPriorityAndReasonChanged(
+    const FrameNode* frame_node,
+    const PriorityAndReason& previous_value) {
   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
-  DCHECK(graph->IsEmpty());
-  graph->RegisterObject(this);
-  graph->AddFrameNodeObserver(this);
-  graph->AddWorkerNodeObserver(this);
-}
-
-void ExecutionContextRegistryImpl::OnTakenFromGraph(Graph* graph) {
-  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
-  graph->RemoveWorkerNodeObserver(this);
-  graph->RemoveFrameNodeObserver(this);
-  graph->UnregisterObject(this);
+  auto* ec = GetOrCreateExecutionContextForFrameNode(frame_node);
+  DCHECK(ec);
+  for (auto& observer : observers_)
+    observer.OnPriorityAndReasonChanged(ec, previous_value);
 }
 
 void ExecutionContextRegistryImpl::OnWorkerNodeAdded(
@@ -211,6 +227,16 @@ void ExecutionContextRegistryImpl::OnBeforeWorkerNodeRemoved(
   DCHECK_EQ(1u, erased);
 }
 
+void ExecutionContextRegistryImpl::OnPriorityAndReasonChanged(
+    const WorkerNode* worker_node,
+    const PriorityAndReason& previous_value) {
+  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
+  auto* ec = GetOrCreateExecutionContextForWorkerNode(worker_node);
+  DCHECK(ec);
+  for (auto& observer : observers_)
+    observer.OnPriorityAndReasonChanged(ec, previous_value);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // ExecutionContextRegistryImpl::ExecutionContextHash
 

components/performance_manager/execution_context/execution_context_registry_impl.h

@@ -25,9 +25,9 @@ class ExecutionContext;
 // to any nodes being created.
 class ExecutionContextRegistryImpl
     : public ExecutionContextRegistry,
-      public FrameNode::ObserverDefaultImpl,
       public GraphOwned,
       public GraphRegisteredImpl<ExecutionContextRegistryImpl>,
+      public FrameNode::ObserverDefaultImpl,
       public WorkerNode::ObserverDefaultImpl {
  public:
   ExecutionContextRegistryImpl();
@@ -56,17 +56,23 @@ class ExecutionContextRegistryImpl
   }
 
  private:
-  // FrameNode::ObserverDefaultImpl implementation:
-  void OnFrameNodeAdded(const FrameNode* frame_node) override;
-  void OnBeforeFrameNodeRemoved(const FrameNode* frame_node) override;
-
   // GraphOwned implementation:
   void OnPassedToGraph(Graph* graph) override;
   void OnTakenFromGraph(Graph* graph) override;
 
+  // FrameNode::ObserverDefaultImpl implementation:
+  void OnFrameNodeAdded(const FrameNode* frame_node) override;
+  void OnBeforeFrameNodeRemoved(const FrameNode* frame_node) override;
+  void OnPriorityAndReasonChanged(
+      const FrameNode* frame_node,
+      const PriorityAndReason& previous_value) override;
+
   // WorkerNode::ObserverDefaultImpl implementation:
   void OnWorkerNodeAdded(const WorkerNode* worker_node) override;
   void OnBeforeWorkerNodeRemoved(const WorkerNode* worker_node) override;
+  void OnPriorityAndReasonChanged(
+      const WorkerNode* worker_node,
+      const PriorityAndReason& previous_value) override;
 
   // Maintains the collection of all currently known ExecutionContexts in the
   // Graph. It is expected that there are O(100s) to O(1000s) of these being
@@ -94,4 +100,4 @@ class ExecutionContextRegistryImpl
 }  // namespace execution_context
 }  // namespace performance_manager
 
-#endif  // COMPONENTS_PERFORMANCE_MANAGER_PUBLIC_EXECUTION_CONTEXT_EXECUTION_CONTEXT_REGISTRY_H_
\ No newline at end of file
+#endif  // COMPONENTS_PERFORMANCE_MANAGER_PUBLIC_EXECUTION_CONTEXT_EXECUTION_CONTEXT_REGISTRY_H_

components/performance_manager/execution_context/execution_context_registry_impl_unittest.cc

@@ -35,6 +35,11 @@ class LenientMockExecutionContextObserver : public ExecutionContextObserver {
               OnBeforeExecutionContextRemoved,
               (const ExecutionContext*),
               ());
+  MOCK_METHOD(void,
+              OnPriorityAndReasonChanged,
+              (const ExecutionContext*,
+               const PriorityAndReason& previous_value),
+              ());
 };
 using MockExecutionContextObserver =
     testing::StrictMock<LenientMockExecutionContextObserver>;
@@ -70,31 +75,16 @@ TEST_F(ExecutionContextRegistryImplTest, RegistryWorks) {
   // Ensure that the public getter works.
   EXPECT_EQ(registry_, ExecutionContextRegistry::GetFromGraph(graph()));
 
-  // Create an observer.
-  MockExecutionContextObserver obs;
-  EXPECT_FALSE(registry_->HasObserver(&obs));
-  registry_->AddObserver(&obs);
-  EXPECT_TRUE(registry_->HasObserver(&obs));
-
   // Create some mock nodes. This creates a graph with 1 page containing 2
   // frames in 1 process.
-  std::vector<const ExecutionContext*> ecs;
-  EXPECT_CALL(obs, OnExecutionContextAdded(testing::_))
-      .Times(2)
-      .WillRepeatedly(
-          [&ecs](const ExecutionContext* ec) { ecs.push_back(ec); });
   MockMultiplePagesInSingleProcessGraph mock_graph(graph());
 
   // Only the frames are in the map at this point.
-  EXPECT_EQ(2u, ecs.size());
   EXPECT_EQ(2u, registry_->GetExecutionContextCountForTesting());
 
   // Creating a worker should create another entry in the map.
-  EXPECT_CALL(obs, OnExecutionContextAdded(testing::_))
-      .WillOnce([&ecs](const ExecutionContext* ec) { ecs.push_back(ec); });
   auto worker_node = CreateNode<WorkerNodeImpl>(
       WorkerNode::WorkerType::kDedicated, mock_graph.process.get());
-  EXPECT_EQ(3u, ecs.size());
   EXPECT_EQ(3u, registry_->GetExecutionContextCountForTesting());
 
   auto* frame1 = mock_graph.frame.get();
@@ -106,11 +96,6 @@ TEST_F(ExecutionContextRegistryImplTest, RegistryWorks) {
   auto* frame2_ec = GetOrCreateExecutionContextForFrameNode(frame2);
   auto* worker_ec = GetOrCreateExecutionContextForWorkerNode(worker);
 
-  // Expect them to match those that were seen by the observer.
-  EXPECT_EQ(ecs[0], frame1_ec);
-  EXPECT_EQ(ecs[1], frame2_ec);
-  EXPECT_EQ(ecs[2], worker_ec);
-
   // Expect the FrameExecutionContext implementation to work.
   EXPECT_EQ(ExecutionContextType::kFrameNode, frame1_ec->GetType());
   EXPECT_EQ(frame1->frame_token().value(), frame1_ec->GetToken().value());
@@ -154,15 +139,45 @@ TEST_F(ExecutionContextRegistryImplTest, RegistryWorks) {
       registry_->GetExecutionContextByToken(blink::ExecutionContextToken()));
   EXPECT_FALSE(registry_->GetFrameNodeByFrameToken(blink::LocalFrameToken()));
   EXPECT_FALSE(registry_->GetWorkerNodeByWorkerToken(blink::WorkerToken()));
+}
+
+TEST_F(ExecutionContextRegistryImplTest, Observers) {
+  // Create an observer.
+  MockExecutionContextObserver obs;
+  EXPECT_FALSE(registry_->HasObserver(&obs));
+  registry_->AddObserver(&obs);
+  EXPECT_TRUE(registry_->HasObserver(&obs));
+
+  // Create some mock nodes. This creates a graph with 1 page containing 1 frame
+  // and 1 worker in a single process.
+  EXPECT_CALL(obs, OnExecutionContextAdded(testing::_)).Times(2);
+  MockSinglePageWithFrameAndWorkerInSingleProcessGraph mock_graph(graph());
+
+  // The registry has 2 entries: the frame and the worker.
+  EXPECT_EQ(2u, registry_->GetExecutionContextCountForTesting());
+
+  auto* frame = mock_graph.frame.get();
+  auto* worker = mock_graph.worker.get();
+
+  // Get the execution contexts for each node directly.
+  auto* frame_ec = GetOrCreateExecutionContextForFrameNode(frame);
+  auto* worker_ec = GetOrCreateExecutionContextForWorkerNode(worker);
+
+  // Set the priority and reason of the frame and expect a notification.
+  EXPECT_CALL(obs, OnPriorityAndReasonChanged(frame_ec, testing::_));
+  frame->SetPriorityAndReason(
+      PriorityAndReason(base::TaskPriority::HIGHEST, "frame reason"));
+
+  // Set the priority and reason of the worker and expect a notification.
+  EXPECT_CALL(obs, OnPriorityAndReasonChanged(worker_ec, testing::_));
+  worker->SetPriorityAndReason(
+      PriorityAndReason(base::TaskPriority::HIGHEST, "worker reason"));
 
   // Destroy nodes one by one and expect observer notifications.
   EXPECT_CALL(obs, OnBeforeExecutionContextRemoved(worker_ec));
-  worker_node.reset();
-  EXPECT_EQ(2u, registry_->GetExecutionContextCountForTesting());
-  EXPECT_CALL(obs, OnBeforeExecutionContextRemoved(frame2_ec));
-  mock_graph.other_frame.reset();
+  mock_graph.DeleteWorker();
   EXPECT_EQ(1u, registry_->GetExecutionContextCountForTesting());
-  EXPECT_CALL(obs, OnBeforeExecutionContextRemoved(frame1_ec));
+  EXPECT_CALL(obs, OnBeforeExecutionContextRemoved(frame_ec));
   mock_graph.frame.reset();
   EXPECT_EQ(0u, registry_->GetExecutionContextCountForTesting());
 

components/performance_manager/public/execution_context/execution_context.h

@@ -6,6 +6,7 @@
 #define COMPONENTS_PERFORMANCE_MANAGER_PUBLIC_EXECUTION_CONTEXT_EXECUTION_CONTEXT_H_
 
 #include "base/observer_list_types.h"
+#include "components/performance_manager/public/execution_context_priority/execution_context_priority.h"
 #include "third_party/blink/public/common/tokens/tokens.h"
 
 class GURL;
@@ -17,6 +18,8 @@ class Graph;
 class ProcessNode;
 class WorkerNode;
 
+using execution_context_priority::PriorityAndReason;
+
 namespace execution_context {
 
 class ExecutionContextObserver;
@@ -73,6 +76,10 @@ class ExecutionContext {
   // ExecutionContext is hosted. This will never return nullptr.
   virtual const ProcessNode* GetProcessNode() const = 0;
 
+  // Returns the current priority of the execution context, and the reason for
+  // the execution context having that particular priority.
+  virtual const PriorityAndReason& GetPriorityAndReason() const = 0;
+
   // Returns the underlying FrameNode, if this context is a FrameNode, or
   // nullptr otherwise.
   virtual const FrameNode* GetFrameNode() const = 0;
@@ -97,6 +104,11 @@ class ExecutionContextObserver : public base::CheckedObserver {
   // Called when an ExecutionContext is about to be removed. The pointer |ec|
   // becomes invalid immediately after this returns.
   virtual void OnBeforeExecutionContextRemoved(const ExecutionContext* ec) = 0;
+
+  // Invoked when the execution context priority and reason changes.
+  virtual void OnPriorityAndReasonChanged(
+      const ExecutionContext* ec,
+      const PriorityAndReason& previous_value) = 0;
 };
 
 // A default implementation of ExecutionContextObserver with empty stubs for all
@@ -113,6 +125,9 @@ class ExecutionContextObserverDefaultImpl : public ExecutionContextObserver {
   // ExecutionContextObserver implementation:
   void OnExecutionContextAdded(const ExecutionContext* ec) override {}
   void OnBeforeExecutionContextRemoved(const ExecutionContext* ec) override {}
+  void OnPriorityAndReasonChanged(
+      const ExecutionContext* ec,
+      const PriorityAndReason& previous_value) override {}
 };
 
 // Helper function for converting from a WorkerToken to an

components/performance_manager/test_support/mock_graphs.cc

@@ -87,4 +87,26 @@ MockMultiplePagesWithMultipleProcessesGraph::
 MockMultiplePagesWithMultipleProcessesGraph::
     ~MockMultiplePagesWithMultipleProcessesGraph() = default;
 
+MockSinglePageWithFrameAndWorkerInSingleProcessGraph::
+    MockSinglePageWithFrameAndWorkerInSingleProcessGraph(TestGraphImpl* graph)
+    : MockSinglePageInSingleProcessGraph(graph),
+      worker(TestNodeWrapper<WorkerNodeImpl>::Create(
+          graph,
+          WorkerNode::WorkerType::kDedicated,
+          process.get())) {
+  worker->AddClientFrame(frame.get());
+}
+
+MockSinglePageWithFrameAndWorkerInSingleProcessGraph::
+    ~MockSinglePageWithFrameAndWorkerInSingleProcessGraph() {
+  if (worker.get())
+    worker->RemoveClientFrame(frame.get());
+}
+
+void MockSinglePageWithFrameAndWorkerInSingleProcessGraph::DeleteWorker() {
+  DCHECK(worker.get());
+  worker->RemoveClientFrame(frame.get());
+  worker.reset();
+}
+
 }  // namespace performance_manager

components/performance_manager/test_support/mock_graphs.h

@@ -116,6 +116,30 @@ struct MockMultiplePagesWithMultipleProcessesGraph
   TestNodeWrapper<FrameNodeImpl> child_frame;
 };
 
+// The following graph topology is created to emulate a scenario where a page
+// contains a single frame that creates a single dedicated worker.
+//
+// Pg  Pr_
+//  \ /   |
+//   F    |
+//    \   |
+//     W__|
+//
+// Where:
+// Pg: page
+// F: frame(frame_tree_id:0)
+// W: worker
+// Pr: process(pid:1)
+struct MockSinglePageWithFrameAndWorkerInSingleProcessGraph
+    : public MockSinglePageInSingleProcessGraph {
+  explicit MockSinglePageWithFrameAndWorkerInSingleProcessGraph(
+      TestGraphImpl* graph);
+  ~MockSinglePageWithFrameAndWorkerInSingleProcessGraph();
+  TestNodeWrapper<WorkerNodeImpl> worker;
+
+  void DeleteWorker();
+};
+
 }  // namespace performance_manager
 
 #endif  // COMPONENTS_PERFORMANCE_MANAGER_TEST_SUPPORT_MOCK_GRAPHS_H_