Reference CL for the new task scheduler.

base/task_scheduler/delayed_task_manager.cc

Index: base/task_scheduler/delayed_task_manager.cc
diff --git a/base/task_scheduler/delayed_task_manager.cc b/base/task_scheduler/delayed_task_manager.cc
new file mode 100644
index 0000000000000000000000000000000000000000..fda8d3bba0d0245ee3297647dc9ff56825e88b65
--- /dev/null
+++ b/base/task_scheduler/delayed_task_manager.cc
@@ -0,0 +1,106 @@
+// Copyright 2016 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 "base/task_scheduler/delayed_task_manager.h"
+
+#include <vector>
+
+#include "base/logging.h"
+#include "base/task_scheduler/utils.h"
+
+namespace base {
+namespace internal {
+
+DelayedTaskManager::DelayedTaskManager(const Closure& delayed_run_time_changed,
+                                       ShutdownManager* shutdown_manager)
+    : next_delayed_task_index_(0),
+      delayed_run_time_changed_(delayed_run_time_changed),
+      shutdown_manager_(shutdown_manager) {
+  DCHECK(!delayed_run_time_changed_.is_null());
+  DCHECK(shutdown_manager_);
+}
+
+DelayedTaskManager::~DelayedTaskManager() = default;
+
+void DelayedTaskManager::AddDelayedTask(const Task& task,
+                                        scoped_refptr<Sequence> sequence,
+                                        PriorityQueue* priority_queue) {
+  DCHECK_NE(TimeTicks(), task.delayed_run_time);
+  DCHECK(sequence.get());
+  DCHECK(priority_queue);
+
+  TimeTicks previous_delayed_run_time;
+
+  {
+    AutoSchedulerLock auto_lock(lock_);
+
+    DelayedTask delayed_task;
+    delayed_task.task = task;
+    delayed_task.sequence = sequence;
+    delayed_task.priority_queue = priority_queue;
+    delayed_task.index = next_delayed_task_index_;
+    ++next_delayed_task_index_;
+
+    if (!delayed_tasks_.empty())
+      previous_delayed_run_time = delayed_tasks_.top().task.delayed_run_time;
+
+    delayed_tasks_.push(delayed_task);
+  }
+
+  if (previous_delayed_run_time.is_null() ||
+      task.delayed_run_time < previous_delayed_run_time) {
+    delayed_run_time_changed_.Run();
+  }
+}
+
+void DelayedTaskManager::PostReadyTasks() {
+  // Get delayed tasks that are ready for execution. Don't post them right away
+  // to avoid holding multiple locks at the same time.
+  const TimeTicks now = Now();
+  std::vector<DelayedTask> ready_tasks;
+
+  {
+    AutoSchedulerLock auto_lock(lock_);
+    while (!delayed_tasks_.empty() &&
+           delayed_tasks_.top().task.delayed_run_time <= now) {
+      ready_tasks.push_back(delayed_tasks_.top());
+      delayed_tasks_.pop();
+    }
+  }
+
+  // Post delayed tasks that are ready for execution.
+  for (const auto& delayed_task : ready_tasks) {
+    PostTaskNowHelper(delayed_task.task, delayed_task.sequence,
+                      delayed_task.priority_queue, shutdown_manager_);
+  }
+}
+
+TimeTicks DelayedTaskManager::GetNextDelayedRunTime() const {
+  AutoSchedulerLock auto_lock(lock_);
+
+  if (delayed_tasks_.empty())
+    return TimeTicks();
+
+  return delayed_tasks_.top().task.delayed_run_time;
+}
+
+TimeTicks DelayedTaskManager::Now() {
+  return TimeTicks::Now();
+}
+
+DelayedTaskManager::DelayedTask::DelayedTask() = default;
+
+DelayedTaskManager::DelayedTask::~DelayedTask() = default;
+
+bool DelayedTaskManager::DelayedTask::operator<(
+    const DelayedTask& other) const {
+  if (task.delayed_run_time > other.task.delayed_run_time)
+    return true;
+  if (task.delayed_run_time < other.task.delayed_run_time)
+    return false;
+  return index > other.index;
+}
+
+}  // namespace internal
+}  // namespace base