Revert of scheduler: Add a base directory

components/scheduler/child/task_queue_impl.cc

+// Copyright 2015 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 "components/scheduler/child/task_queue_impl.h"
+
+#include "components/scheduler/child/task_queue_manager.h"
+
+namespace scheduler {
+namespace internal {
+
+TaskQueueImpl::TaskQueueImpl(
+    TaskQueueManager* task_queue_manager,
+    const Spec& spec,
+    const char* disabled_by_default_tracing_category,
+    const char* disabled_by_default_verbose_tracing_category)
+    : thread_id_(base::PlatformThread::CurrentId()),
+      task_queue_manager_(task_queue_manager),
+      pump_policy_(spec.pump_policy),
+      name_(spec.name),
+      disabled_by_default_tracing_category_(
+          disabled_by_default_tracing_category),
+      disabled_by_default_verbose_tracing_category_(
+          disabled_by_default_verbose_tracing_category),
+      wakeup_policy_(spec.wakeup_policy),
+      set_index_(0),
+      should_monitor_quiescence_(spec.should_monitor_quiescence),
+      should_notify_observers_(spec.should_notify_observers) {}
+
+TaskQueueImpl::~TaskQueueImpl() {}
+
+TaskQueueImpl::Task::Task()
+    : PendingTask(tracked_objects::Location(),
+                  base::Closure(),
+                  base::TimeTicks(),
+                  true),
+#ifndef NDEBUG
+      enqueue_order_set_(false),
+#endif
+      enqueue_order_(0) {
+  sequence_num = 0;
+}
+
+TaskQueueImpl::Task::Task(const tracked_objects::Location& posted_from,
+                          const base::Closure& task,
+                          int sequence_number,
+                          bool nestable)
+    : PendingTask(posted_from, task, base::TimeTicks(), nestable),
+#ifndef NDEBUG
+      enqueue_order_set_(false),
+#endif
+      enqueue_order_(0) {
+  sequence_num = sequence_number;
+}
+
+void TaskQueueImpl::UnregisterTaskQueue() {
+  if (!task_queue_manager_)
+    return;
+  task_queue_manager_->UnregisterTaskQueue(this);
+
+  {
+    base::AutoLock lock(lock_);
+    task_queue_manager_ = nullptr;
+    delayed_task_queue_ = std::priority_queue<Task>();
+    incoming_queue_ = std::queue<Task>();
+    work_queue_ = std::queue<Task>();
+  }
+}
+
+bool TaskQueueImpl::RunsTasksOnCurrentThread() const {
+  base::AutoLock lock(lock_);
+  return base::PlatformThread::CurrentId() == thread_id_;
+}
+
+bool TaskQueueImpl::PostDelayedTask(const tracked_objects::Location& from_here,
+                                    const base::Closure& task,
+                                    base::TimeDelta delay) {
+  return PostDelayedTaskImpl(from_here, task, delay, TaskType::NORMAL);
+}
+
+bool TaskQueueImpl::PostNonNestableDelayedTask(
+    const tracked_objects::Location& from_here,
+    const base::Closure& task,
+    base::TimeDelta delay) {
+  return PostDelayedTaskImpl(from_here, task, delay, TaskType::NON_NESTABLE);
+}
+
+bool TaskQueueImpl::PostDelayedTaskAt(
+    const tracked_objects::Location& from_here,
+    const base::Closure& task,
+    base::TimeTicks desired_run_time) {
+  base::AutoLock lock(lock_);
+  if (!task_queue_manager_)
+    return false;
+  LazyNow lazy_now(task_queue_manager_);
+  return PostDelayedTaskLocked(&lazy_now, from_here, task, desired_run_time,
+                               TaskType::NORMAL);
+}
+
+bool TaskQueueImpl::PostDelayedTaskImpl(
+    const tracked_objects::Location& from_here,
+    const base::Closure& task,
+    base::TimeDelta delay,
+    TaskType task_type) {
+  base::AutoLock lock(lock_);
+  if (!task_queue_manager_)
+    return false;
+  LazyNow lazy_now(task_queue_manager_);
+  base::TimeTicks desired_run_time;
+  if (delay > base::TimeDelta())
+    desired_run_time = lazy_now.Now() + delay;
+  return PostDelayedTaskLocked(&lazy_now, from_here, task, desired_run_time,
+                               task_type);
+}
+
+bool TaskQueueImpl::PostDelayedTaskLocked(
+    LazyNow* lazy_now,
+    const tracked_objects::Location& from_here,
+    const base::Closure& task,
+    base::TimeTicks desired_run_time,
+    TaskType task_type) {
+  lock_.AssertAcquired();
+  DCHECK(task_queue_manager_);
+  Task pending_task(from_here, task,
+                    task_queue_manager_->GetNextSequenceNumber(),
+                    task_type != TaskType::NON_NESTABLE);
+  task_queue_manager_->DidQueueTask(pending_task);
+
+  if (!desired_run_time.is_null()) {
+    pending_task.delayed_run_time = std::max(lazy_now->Now(), desired_run_time);
+    // TODO(alexclarke): consider emplace() when C++11 library features allowed.
+    delayed_task_queue_.push(pending_task);
+    TraceQueueSize(true);
+    // Schedule a later call to MoveReadyDelayedTasksToIncomingQueue.
+    task_queue_manager_->ScheduleDelayedWork(this, desired_run_time, lazy_now);
+    return true;
+  }
+  pending_task.set_enqueue_order(pending_task.sequence_num);
+  EnqueueTaskLocked(pending_task);
+  return true;
+}
+
+void TaskQueueImpl::MoveReadyDelayedTasksToIncomingQueue(LazyNow* lazy_now) {
+  base::AutoLock lock(lock_);
+  if (!task_queue_manager_)
+    return;
+
+  MoveReadyDelayedTasksToIncomingQueueLocked(lazy_now);
+}
+
+void TaskQueueImpl::MoveReadyDelayedTasksToIncomingQueueLocked(
+    LazyNow* lazy_now) {
+  lock_.AssertAcquired();
+  // Enqueue all delayed tasks that should be running now.
+  while (!delayed_task_queue_.empty() &&
+         delayed_task_queue_.top().delayed_run_time <= lazy_now->Now()) {
+    // TODO(alexclarke): consider std::move() when allowed.
+    EnqueueDelayedTaskLocked(delayed_task_queue_.top());
+    delayed_task_queue_.pop();
+  }
+  TraceQueueSize(true);
+}
+
+bool TaskQueueImpl::IsQueueEnabled() const {
+  DCHECK(main_thread_checker_.CalledOnValidThread());
+  if (!task_queue_manager_)
+    return false;
+
+  return task_queue_manager_->selector_.IsQueueEnabled(this);
+}
+
+TaskQueue::QueueState TaskQueueImpl::GetQueueState() const {
+  DCHECK(main_thread_checker_.CalledOnValidThread());
+  if (!work_queue_.empty())
+    return QueueState::HAS_WORK;
+
+  {
+    base::AutoLock lock(lock_);
+    if (incoming_queue_.empty()) {
+      return QueueState::EMPTY;
+    } else {
+      return QueueState::NEEDS_PUMPING;
+    }
+  }
+}
+
+bool TaskQueueImpl::TaskIsOlderThanQueuedTasks(const Task* task) {
+  lock_.AssertAcquired();
+  // A null task is passed when UpdateQueue is called before any task is run.
+  // In this case we don't want to pump an after_wakeup queue, so return true
+  // here.
+  if (!task)
+    return true;
+
+  // Return false if there are no task in the incoming queue.
+  if (incoming_queue_.empty())
+    return false;
+
+  const TaskQueueImpl::Task& oldest_queued_task = incoming_queue_.front();
+  return task->enqueue_order() < oldest_queued_task.enqueue_order();
+}
+
+bool TaskQueueImpl::ShouldAutoPumpQueueLocked(bool should_trigger_wakeup,
+                                              const Task* previous_task) {
+  lock_.AssertAcquired();
+  if (pump_policy_ == PumpPolicy::MANUAL)
+    return false;
+  if (pump_policy_ == PumpPolicy::AFTER_WAKEUP &&
+      (!should_trigger_wakeup || TaskIsOlderThanQueuedTasks(previous_task)))
+    return false;
+  if (incoming_queue_.empty())
+    return false;
+  return true;
+}
+
+bool TaskQueueImpl::NextPendingDelayedTaskRunTime(
+    base::TimeTicks* next_pending_delayed_task) {
+  base::AutoLock lock(lock_);
+  if (delayed_task_queue_.empty())
+    return false;
+  *next_pending_delayed_task = delayed_task_queue_.top().delayed_run_time;
+  return true;
+}
+
+void TaskQueueImpl::UpdateWorkQueue(LazyNow* lazy_now,
+                                    bool should_trigger_wakeup,
+                                    const Task* previous_task) {
+  DCHECK(work_queue_.empty());
+  base::AutoLock lock(lock_);
+  if (!ShouldAutoPumpQueueLocked(should_trigger_wakeup, previous_task))
+    return;
+  MoveReadyDelayedTasksToIncomingQueueLocked(lazy_now);
+  std::swap(work_queue_, incoming_queue_);
+  // |incoming_queue_| is now empty so TaskQueueManager::UpdateQueues no
+  // longer needs to consider this queue for reloading.
+  task_queue_manager_->UnregisterAsUpdatableTaskQueue(this);
+  if (!work_queue_.empty()) {
+    DCHECK(task_queue_manager_);
+    task_queue_manager_->selector_.GetTaskQueueSets()->OnPushQueue(this);
+    TraceQueueSize(true);
+  }
+}
+
+TaskQueueImpl::Task TaskQueueImpl::TakeTaskFromWorkQueue() {
+  // TODO(alexclarke): consider std::move() when allowed.
+  Task pending_task = work_queue_.front();
+  work_queue_.pop();
+  DCHECK(task_queue_manager_);
+  task_queue_manager_->selector_.GetTaskQueueSets()->OnPopQueue(this);
+  TraceQueueSize(false);
+  return pending_task;
+}
+
+void TaskQueueImpl::TraceQueueSize(bool is_locked) const {
+  bool is_tracing;
+  TRACE_EVENT_CATEGORY_GROUP_ENABLED(disabled_by_default_tracing_category_,
+                                     &is_tracing);
+  if (!is_tracing)
+    return;
+  if (!is_locked)
+    lock_.Acquire();
+  else
+    lock_.AssertAcquired();
+  TRACE_COUNTER1(
+      disabled_by_default_tracing_category_, GetName(),
+      incoming_queue_.size() + work_queue_.size() + delayed_task_queue_.size());
+  if (!is_locked)
+    lock_.Release();
+}
+
+void TaskQueueImpl::EnqueueTaskLocked(const Task& pending_task) {
+  lock_.AssertAcquired();
+  if (!task_queue_manager_)
+    return;
+  if (incoming_queue_.empty())
+    task_queue_manager_->RegisterAsUpdatableTaskQueue(this);
+  if (pump_policy_ == PumpPolicy::AUTO && incoming_queue_.empty()) {
+    task_queue_manager_->MaybePostDoWorkOnMainRunner();
+  }
+  // TODO(alexclarke): consider std::move() when allowed.
+  incoming_queue_.push(pending_task);
+  TraceQueueSize(true);
+}
+
+void TaskQueueImpl::EnqueueDelayedTaskLocked(const Task& pending_task) {
+  lock_.AssertAcquired();
+  if (!task_queue_manager_)
+    return;
+  if (incoming_queue_.empty())
+    task_queue_manager_->RegisterAsUpdatableTaskQueue(this);
+  // TODO(alexclarke): consider std::move() when allowed.
+  incoming_queue_.push(pending_task);
+  incoming_queue_.back().set_enqueue_order(
+      task_queue_manager_->GetNextSequenceNumber());
+  TraceQueueSize(true);
+}
+
+void TaskQueueImpl::SetPumpPolicy(PumpPolicy pump_policy) {
+  base::AutoLock lock(lock_);
+  if (pump_policy == PumpPolicy::AUTO && pump_policy_ != PumpPolicy::AUTO) {
+    PumpQueueLocked();
+  }
+  pump_policy_ = pump_policy;
+}
+
+void TaskQueueImpl::PumpQueueLocked() {
+  lock_.AssertAcquired();
+  if (!task_queue_manager_)
+    return;
+
+  LazyNow lazy_now(task_queue_manager_);
+  MoveReadyDelayedTasksToIncomingQueueLocked(&lazy_now);
+
+  bool was_empty = work_queue_.empty();
+  while (!incoming_queue_.empty()) {
+    // TODO(alexclarke): consider std::move() when allowed.
+    work_queue_.push(incoming_queue_.front());
+    incoming_queue_.pop();
+  }
+  // |incoming_queue_| is now empty so TaskQueueManager::UpdateQueues no longer
+  // needs to consider this queue for reloading.
+  task_queue_manager_->UnregisterAsUpdatableTaskQueue(this);
+  if (!work_queue_.empty()) {
+    if (was_empty)
+      task_queue_manager_->selector_.GetTaskQueueSets()->OnPushQueue(this);
+    task_queue_manager_->MaybePostDoWorkOnMainRunner();
+  }
+}
+
+void TaskQueueImpl::PumpQueue() {
+  base::AutoLock lock(lock_);
+  PumpQueueLocked();
+}
+
+const char* TaskQueueImpl::GetName() const {
+  return name_;
+}
+
+bool TaskQueueImpl::GetWorkQueueFrontTaskEnqueueOrder(
+    int* enqueue_order) const {
+  if (work_queue_.empty())
+    return false;
+  *enqueue_order = work_queue_.front().enqueue_order();
+  return true;
+}
+
+void TaskQueueImpl::PushTaskOntoWorkQueueForTest(const Task& task) {
+  work_queue_.push(task);
+}
+
+void TaskQueueImpl::PopTaskFromWorkQueueForTest() {
+  work_queue_.pop();
+}
+
+void TaskQueueImpl::SetQueuePriority(QueuePriority priority) {
+  DCHECK(main_thread_checker_.CalledOnValidThread());
+  if (!task_queue_manager_)
+    return;
+
+  task_queue_manager_->selector_.SetQueuePriority(this, priority);
+}
+
+// static
+const char* TaskQueueImpl::PumpPolicyToString(
+    TaskQueue::PumpPolicy pump_policy) {
+  switch (pump_policy) {
+    case TaskQueue::PumpPolicy::AUTO:
+      return "auto";
+    case TaskQueue::PumpPolicy::AFTER_WAKEUP:
+      return "after_wakeup";
+    case TaskQueue::PumpPolicy::MANUAL:
+      return "manual";
+    default:
+      NOTREACHED();
+      return nullptr;
+  }
+}
+
+// static
+const char* TaskQueueImpl::WakeupPolicyToString(
+    TaskQueue::WakeupPolicy wakeup_policy) {
+  switch (wakeup_policy) {
+    case TaskQueue::WakeupPolicy::CAN_WAKE_OTHER_QUEUES:
+      return "can_wake_other_queues";
+    case TaskQueue::WakeupPolicy::DONT_WAKE_OTHER_QUEUES:
+      return "dont_wake_other_queues";
+    default:
+      NOTREACHED();
+      return nullptr;
+  }
+}
+
+// static
+const char* TaskQueueImpl::PriorityToString(QueuePriority priority) {
+  switch (priority) {
+    case CONTROL_PRIORITY:
+      return "control";
+    case HIGH_PRIORITY:
+      return "high";
+    case NORMAL_PRIORITY:
+      return "normal";
+    case BEST_EFFORT_PRIORITY:
+      return "best_effort";
+    case DISABLED_PRIORITY:
+      return "disabled";
+    default:
+      NOTREACHED();
+      return nullptr;
+  }
+}
+
+void TaskQueueImpl::AsValueInto(base::trace_event::TracedValue* state) const {
+  base::AutoLock lock(lock_);
+  state->BeginDictionary();
+  state->SetString("name", GetName());
+  state->SetString("pump_policy", PumpPolicyToString(pump_policy_));
+  state->SetString("wakeup_policy", WakeupPolicyToString(wakeup_policy_));
+  bool verbose_tracing_enabled = false;
+  TRACE_EVENT_CATEGORY_GROUP_ENABLED(
+      disabled_by_default_verbose_tracing_category_, &verbose_tracing_enabled);
+  state->SetInteger("incoming_queue_size", incoming_queue_.size());
+  state->SetInteger("work_queue_size", work_queue_.size());
+  state->SetInteger("delayed_task_queue_size", delayed_task_queue_.size());
+  if (verbose_tracing_enabled) {
+    state->BeginArray("incoming_queue");
+    QueueAsValueInto(incoming_queue_, state);
+    state->EndArray();
+    state->BeginArray("work_queue");
+    QueueAsValueInto(work_queue_, state);
+    state->EndArray();
+    state->BeginArray("delayed_task_queue");
+    QueueAsValueInto(delayed_task_queue_, state);
+    state->EndArray();
+  }
+  state->SetString("priority",
+                   PriorityToString(static_cast<QueuePriority>(set_index_)));
+  state->EndDictionary();
+}
+
+void TaskQueueImpl::AddTaskObserver(
+    base::MessageLoop::TaskObserver* task_observer) {
+  DCHECK(main_thread_checker_.CalledOnValidThread());
+  task_observers_.AddObserver(task_observer);
+}
+
+void TaskQueueImpl::RemoveTaskObserver(
+    base::MessageLoop::TaskObserver* task_observer) {
+  DCHECK(main_thread_checker_.CalledOnValidThread());
+  task_observers_.RemoveObserver(task_observer);
+}
+
+void TaskQueueImpl::NotifyWillProcessTask(
+    const base::PendingTask& pending_task) {
+  DCHECK(main_thread_checker_.CalledOnValidThread());
+  DCHECK(should_notify_observers_);
+  FOR_EACH_OBSERVER(base::MessageLoop::TaskObserver, task_observers_,
+                    WillProcessTask(pending_task));
+}
+
+void TaskQueueImpl::NotifyDidProcessTask(
+    const base::PendingTask& pending_task) {
+  DCHECK(main_thread_checker_.CalledOnValidThread());
+  DCHECK(should_notify_observers_);
+  FOR_EACH_OBSERVER(base::MessageLoop::TaskObserver, task_observers_,
+                    DidProcessTask(pending_task));
+}
+
+// static
+void TaskQueueImpl::QueueAsValueInto(const std::queue<Task>& queue,
+                                     base::trace_event::TracedValue* state) {
+  std::queue<Task> queue_copy(queue);
+  while (!queue_copy.empty()) {
+    TaskAsValueInto(queue_copy.front(), state);
+    queue_copy.pop();
+  }
+}
+
+// static
+void TaskQueueImpl::QueueAsValueInto(const std::priority_queue<Task>& queue,
+                                     base::trace_event::TracedValue* state) {
+  std::priority_queue<Task> queue_copy(queue);
+  while (!queue_copy.empty()) {
+    TaskAsValueInto(queue_copy.top(), state);
+    queue_copy.pop();
+  }
+}
+
+// static
+void TaskQueueImpl::TaskAsValueInto(const Task& task,
+                                    base::trace_event::TracedValue* state) {
+  state->BeginDictionary();
+  state->SetString("posted_from", task.posted_from.ToString());
+  state->SetInteger("enqueue_order", task.enqueue_order());
+  state->SetInteger("sequence_num", task.sequence_num);
+  state->SetBoolean("nestable", task.nestable);
+  state->SetBoolean("is_high_res", task.is_high_res);
+  state->SetDouble(
+      "delayed_run_time",
+      (task.delayed_run_time - base::TimeTicks()).InMicroseconds() / 1000.0L);
+  state->EndDictionary();
+}
+
+}  // namespace internal
+}  // namespace scheduler