TaskScheduler [7] SchedulerThreadPool

base/task_scheduler/utils.cc

+// 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/utils.h"
+
+#include <utility>
+
+#include "base/callback.h"
+#include "base/logging.h"
+#include "base/memory/ptr_util.h"
+#include "base/task_scheduler/priority_queue.h"
+#include "base/task_scheduler/scheduler_task_executor.h"
+#include "base/task_scheduler/sequence_sort_key.h"
+#include "base/task_scheduler/task_tracker.h"
+#include "base/time/time.h"
+
+namespace base {
+namespace internal {
+
+bool PostTaskToExecutor(const tracked_objects::Location& posted_from,
+                        const Closure& closure,
+                        const TaskTraits& traits,
+                        const TimeDelta& delay,
+                        scoped_refptr<Sequence> sequence,
+                        SchedulerTaskExecutor* executor,
+                        TaskTracker* task_tracker) {
+  DCHECK(!closure.is_null());
+  DCHECK(sequence);
+  DCHECK(executor);
+  DCHECK(task_tracker);
+
+  // TODO(fdoray): Support delayed tasks.
+  DCHECK(delay.is_zero());
+
+  std::unique_ptr<Task> task(new Task(posted_from, closure, traits));
+
+  if (!task_tracker->WillPostTask(task.get()))
+    return false;
+
+  executor->PostTaskWithSequence(std::move(task), std::move(sequence));
+  return true;
+}
+
+bool AddTaskToSequenceAndPriorityQueue(std::unique_ptr<Task> task,
+                                       scoped_refptr<Sequence> sequence,
+                                       PriorityQueue* priority_queue) {
+  DCHECK(task);
+  DCHECK(sequence);
+  DCHECK(priority_queue);
+
+  // Confirm that |task| is ready to run (its delayed run time is either null or
+  // in the past).
+  DCHECK_LE(task->delayed_run_time, TimeTicks::Now());
+
+  const bool sequence_was_empty = sequence->PushTask(std::move(task));
+  if (sequence_was_empty) {
+    // Insert |sequence| in |priority_queue| if it was empty before |task| was
+    // inserted into it. Otherwise, one of these must be true:
+    // - |sequence| is already in a PriorityQueue (not necessarily
+    //   |priority_queue|), or,
+    // - A worker thread is running a Task from |sequence|. It will insert
+    //   |sequence| in a PriorityQueue once it's done running the Task.
+    const auto sequence_sort_key = sequence->GetSortKey();
+    priority_queue->BeginTransaction()->Push(
+        WrapUnique(new PriorityQueue::SequenceAndSortKey(std::move(sequence),
+                                                         sequence_sort_key)));
+  }
+
+  return sequence_was_empty;
+}
+
+}  // namespace internal
+}  // namespace base