scheduler: Add support for tracing scheduler state

content/renderer/scheduler/task_queue_manager.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/scheduler/task_queue_manager.h"
 
 #include "base/bind.h"
 #include "base/debug/trace_event.h"
+#include "base/debug/trace_event_argument.h"
 #include "content/renderer/scheduler/task_queue_selector.h"
 
 namespace content {
 namespace internal {
 
 class TaskQueue : public base::SingleThreadTaskRunner {
  public:
   TaskQueue(TaskQueueManager* task_queue_manager);
 
   // base::SingleThreadTaskRunner implementation.
@@ skipping 15 matching lines @@
   void SetAutoPump(bool auto_pump);
   void PumpQueue();
 
   bool UpdateWorkQueue();
   base::PendingTask TakeTaskFromWorkQueue();
 
   void WillDeleteTaskQueueManager();
 
   base::TaskQueue& work_queue() { return work_queue_; }
 
+  void set_name(const char* name) { name_ = name; }
+
+  void AsValueInto(base::debug::TracedValue* state) const;
+
  private:
   ~TaskQueue() override;
 
   void PumpQueueLocked();
   void EnqueueTaskLocked(const base::PendingTask& pending_task);
+  void TraceWorkQueueSize() const;
 
   // This lock protects all members except the work queue.
   mutable base::Lock lock_;
   TaskQueueManager* task_queue_manager_;
   base::TaskQueue incoming_queue_;
   bool auto_pump_;
+  const char* name_;
 
   base::TaskQueue work_queue_;
 
   DISALLOW_COPY_AND_ASSIGN(TaskQueue);
 };
 
 TaskQueue::TaskQueue(TaskQueueManager* task_queue_manager)
-    : task_queue_manager_(task_queue_manager), auto_pump_(true) {
+    : task_queue_manager_(task_queue_manager),
+      auto_pump_(true),
+      name_(nullptr) {
 }
 
 TaskQueue::~TaskQueue() {
 }
 
 void TaskQueue::WillDeleteTaskQueueManager() {
   base::AutoLock lock(lock_);
   task_queue_manager_ = nullptr;
 }
 
@@ skipping 45 matching lines @@
 
 bool TaskQueue::UpdateWorkQueue() {
   if (!work_queue_.empty())
     return true;
 
   {
     base::AutoLock lock(lock_);
     if (!auto_pump_ || incoming_queue_.empty())
       return false;
     work_queue_.Swap(&incoming_queue_);
+    TraceWorkQueueSize();
     return true;
   }
 }
 
 base::PendingTask TaskQueue::TakeTaskFromWorkQueue() {
   base::PendingTask pending_task = work_queue_.front();
   work_queue_.pop();
+  TraceWorkQueueSize();
   return pending_task;
 }
 
+void TaskQueue::TraceWorkQueueSize() const {
+  if (!name_)
+    return;
+  TRACE_COUNTER1(TRACE_DISABLED_BY_DEFAULT("renderer.scheduler"),
+                 name_,
+                 work_queue_.size());
+}
+
 void TaskQueue::EnqueueTask(const base::PendingTask& pending_task) {
   base::AutoLock lock(lock_);
   EnqueueTaskLocked(pending_task);
 }
 
 void TaskQueue::EnqueueTaskLocked(const base::PendingTask& pending_task) {
   lock_.AssertAcquired();
   if (!task_queue_manager_)
     return;
   if (auto_pump_ && incoming_queue_.empty())
@@ skipping 19 matching lines @@
   }
   if (!work_queue_.empty())
     task_queue_manager_->PostDoWorkOnMainRunner();
 }
 
 void TaskQueue::PumpQueue() {
   base::AutoLock lock(lock_);
   PumpQueueLocked();
 }
 
-}  // namespace
+void TaskQueue::AsValueInto(base::debug::TracedValue* state) const {
+  base::AutoLock lock(lock_);
+  state->BeginDictionary();
+  if (name_)
+    state->SetString("name", name_);
+  state->SetBoolean("auto_pump", auto_pump_);
+  state->BeginArray("incoming_queue");
+  TaskQueueManager::QueueAsValueInto(incoming_queue_, state);
+  state->EndArray();
+  state->BeginArray("work_queue");
+  TaskQueueManager::QueueAsValueInto(work_queue_, state);
+  state->EndArray();
+  state->EndDictionary();
+}
+
+}  // namespace internal
 
 TaskQueueManager::TaskQueueManager(
     size_t task_queue_count,
     scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
     TaskQueueSelector* selector)
     : main_task_runner_(main_task_runner),
       selector_(selector),
       weak_factory_(this) {
   DCHECK(main_task_runner->RunsTasksOnCurrentThread());
+  TRACE_EVENT_OBJECT_CREATED_WITH_ID(
+      TRACE_DISABLED_BY_DEFAULT("renderer.scheduler"),
+      "TaskQueueManager",
+      this);
 
   task_queue_manager_weak_ptr_ = weak_factory_.GetWeakPtr();
   for (size_t i = 0; i < task_queue_count; i++) {
     scoped_refptr<internal::TaskQueue> queue(
         make_scoped_refptr(new internal::TaskQueue(this)));
     queues_.push_back(queue);
   }
 
   std::vector<const base::TaskQueue*> work_queues;
   for (const auto& queue: queues_)
     work_queues.push_back(&queue->work_queue());
   selector_->RegisterWorkQueues(work_queues);
 }
 
 TaskQueueManager::~TaskQueueManager() {
+  TRACE_EVENT_OBJECT_DELETED_WITH_ID(
+      TRACE_DISABLED_BY_DEFAULT("renderer.scheduler"),
+      "TaskQueueManager",
+      this);
   for (auto& queue : queues_)
     queue->WillDeleteTaskQueueManager();
 }
 
 internal::TaskQueue* TaskQueueManager::Queue(size_t queue_index) const {
   DCHECK_LT(queue_index, queues_.size());
   return queues_[queue_index].get();
 }
 
 scoped_refptr<base::SingleThreadTaskRunner>
@@ skipping 33 matching lines @@
   main_task_runner_->PostTask(
       FROM_HERE, Bind(&TaskQueueManager::DoWork, task_queue_manager_weak_ptr_));
 }
 
 void TaskQueueManager::DoWork() {
   main_thread_checker_.CalledOnValidThread();
   if (!UpdateWorkQueues())
     return;
 
   size_t queue_index;
-  if (!selector_->SelectWorkQueueToService(&queue_index))
+  if (!SelectWorkQueueToService(&queue_index))
     return;
   PostDoWorkOnMainRunner();
   RunTaskFromWorkQueue(queue_index);
 }
 
+bool TaskQueueManager::SelectWorkQueueToService(size_t* out_queue_index) {
+  bool should_run = selector_->SelectWorkQueueToService(out_queue_index);
+  TRACE_EVENT_OBJECT_SNAPSHOT_WITH_ID(
+      TRACE_DISABLED_BY_DEFAULT("renderer.scheduler"),
+      "TaskQueueManager",
+      this,
+      AsValueWithSelectorResult(should_run, *out_queue_index));
+  return should_run;
+}
+
 void TaskQueueManager::DidQueueTask(base::PendingTask* pending_task) {
   pending_task->sequence_num = task_sequence_num_.GetNext();
   task_annotator_.DidQueueTask("TaskQueueManager::PostTask", *pending_task);
 }
 
 void TaskQueueManager::RunTaskFromWorkQueue(size_t queue_index) {
   main_thread_checker_.CalledOnValidThread();
   internal::TaskQueue* queue = Queue(queue_index);
   base::PendingTask pending_task = queue->TakeTaskFromWorkQueue();
   task_annotator_.RunTask(
@@ skipping 13 matching lines @@
 }
 
 bool TaskQueueManager::PostNonNestableDelayedTask(
     const tracked_objects::Location& from_here,
     const base::Closure& task,
     base::TimeDelta delay) {
   // Defer non-nestable work to the main task runner.
   return main_task_runner_->PostNonNestableDelayedTask(from_here, task, delay);
 }
 
+void TaskQueueManager::SetQueueName(size_t queue_index, const char* name) {
+  main_thread_checker_.CalledOnValidThread();
+  internal::TaskQueue* queue = Queue(queue_index);
+  queue->set_name(name);
+}
+
+scoped_refptr<base::debug::ConvertableToTraceFormat>
+TaskQueueManager::AsValueWithSelectorResult(bool should_run,
+                                            size_t selected_queue) const {
+  main_thread_checker_.CalledOnValidThread();
+  scoped_refptr<base::debug::TracedValue> state =
+      new base::debug::TracedValue();
+  state->BeginArray("queues");
+  for (auto& queue : queues_)
+    queue->AsValueInto(state.get());
+  state->EndArray();
+  state->BeginDictionary("selector");
+  selector_->AsValueInto(state.get());
+  state->EndDictionary();
+  if (should_run)
+    state->SetInteger("selected_queue", selected_queue);
+  return state;
+}
+
+// static
+void TaskQueueManager::QueueAsValueInto(const base::TaskQueue& queue,
+                                        base::debug::TracedValue* state) {
+  base::TaskQueue queue_copy(queue);
+  while (!queue_copy.empty()) {
+    TaskAsValueInto(queue_copy.front(), state);
+    queue_copy.pop();
+  }
+}
+
+// static
+void TaskQueueManager::TaskAsValueInto(const base::PendingTask& task,
+                                       base::debug::TracedValue* state) {
+  state->BeginDictionary();
+  state->SetString("posted_from", task.posted_from.ToString());
+  state->SetInteger("sequence_num", task.sequence_num);
+  state->SetBoolean("nestable", task.nestable);
+  state->SetBoolean("is_high_res", task.is_high_res);
+  state->SetDouble(
+      "time_posted",
+      (task.time_posted - base::TimeTicks()).InMicroseconds() / 1000.0L);
+  state->SetDouble(
+      "delayed_run_time",
+      (task.delayed_run_time - base::TimeTicks()).InMicroseconds() / 1000.0L);
+  state->EndDictionary();
+}
+
 }  // namespace content