TaskScheduler [7] SchedulerThreadPool

base/task_scheduler/utils_unittest.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 <memory>
+
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/memory/ptr_util.h"
+#include "base/memory/ref_counted.h"
+#include "base/task_scheduler/priority_queue.h"
+#include "base/task_scheduler/sequence.h"
+#include "base/task_scheduler/task.h"
+#include "base/task_scheduler/task_tracker.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace base {
+namespace internal {
+namespace {
+
+// Checks that when PostTaskHelper is called with an empty sequence, the task
+// is added to the sequence and the sequence is added to the priority queue.
+TEST(TaskSchedulerPostTaskHelperTest, PostTaskInEmptySequence) {
+  std::unique_ptr<Task> task(
+      new Task(FROM_HERE, Bind(&DoNothing), TaskTraits()));
+  const Task* task_raw = task.get();
+  scoped_refptr<Sequence> sequence(new Sequence);
+  PriorityQueue priority_queue(Bind(&DoNothing));
+  TaskTracker task_tracker;
+
+  // Post |task|.
+  EXPECT_TRUE(PostTaskHelper(std::move(task), sequence, &priority_queue,
+                             &task_tracker));
+
+  // Expect to find the sequence in the priority queue.
+  EXPECT_EQ(sequence, priority_queue.BeginTransaction()->Peek().sequence);
+
+  // Expect to find |task| alone in |sequence|.
+  EXPECT_EQ(task_raw, sequence->PeekTask());
+  sequence->PopTask();
+  EXPECT_EQ(nullptr, sequence->PeekTask());
+}
+
+// Checks that when PostTaskHelper is called with a sequence that already
+// contains a task, the task is added to the sequence but the sequence is not
+// added to the priority queue.
+TEST(TaskSchedulerPostTaskHelperTest, PostTaskInNonEmptySequence) {
+  std::unique_ptr<Task> task(
+      new Task(FROM_HERE, Bind(&DoNothing), TaskTraits()));
+  const Task* task_raw = task.get();
+  scoped_refptr<Sequence> sequence(new Sequence);
+  PriorityQueue priority_queue(Bind(&DoNothing));
+  TaskTracker task_tracker;
+
+  // Add an initial task in |sequence|.
+  sequence->PushTask(
+      WrapUnique(new Task(FROM_HERE, Bind(&DoNothing), TaskTraits())));
+
+  // Post |task|.
+  EXPECT_TRUE(PostTaskHelper(std::move(task), sequence, &priority_queue,
+                             &task_tracker));
+
+  // Expect to find the priority queue empty.
+  EXPECT_TRUE(priority_queue.BeginTransaction()->Peek().is_null());
+
+  // Expect to find |task| in |sequence| behind the initial task.
+  EXPECT_NE(task_raw, sequence->PeekTask());
+  sequence->PopTask();
+  EXPECT_EQ(task_raw, sequence->PeekTask());
+  sequence->PopTask();
+  EXPECT_EQ(nullptr, sequence->PeekTask());
+}
+
+}  // namespace
+}  // namespace internal
+}  // namespace base