cc: Add UniqueNotifier to cc/base.

cc/base/delayed_unique_notifier_unittest.cc

Index: cc/base/delayed_unique_notifier_unittest.cc
diff --git a/cc/base/delayed_unique_notifier_unittest.cc b/cc/base/delayed_unique_notifier_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..1a38232145c925709abd7e4ee4fb6d73cf5075c9
--- /dev/null
+++ b/cc/base/delayed_unique_notifier_unittest.cc
@@ -0,0 +1,226 @@
+// 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 <deque>
+
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/test/test_pending_task.h"
+#include "base/test/test_simple_task_runner.h"
+#include "cc/base/delayed_unique_notifier.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace cc {
+namespace {
+
+class TestNotifier : public DelayedUniqueNotifier {
+ public:
+  TestNotifier(base::SequencedTaskRunner* task_runner,
+               const base::Closure& closure,
+               const base::TimeDelta& delay)
+      : DelayedUniqueNotifier(task_runner, closure, delay) {}
+  virtual ~TestNotifier() {}
+
+  virtual base::TimeTicks Now() const OVERRIDE { return now_; }

[reveman, 2014/05/28 19:50:02]

nit: Add // Overridden from DelayedUniqueNotifier:

[vmpstr, 2014/05/28 20:17:13]

Done.

+
+  void SetNow(base::TimeTicks now) { now_ = now; }
+
+ private:
+  base::TimeTicks now_;
+};
+
+class DelayedUniqueNotifierTest : public testing::Test {
+ public:
+  DelayedUniqueNotifierTest() : notification_count_(0) {}
+
+  virtual void SetUp() OVERRIDE {
+    notification_count_ = 0;
+    task_runner_ = make_scoped_refptr(new base::TestSimpleTaskRunner);
+  }
+
+  void Notify() { ++notification_count_; }
+
+  int NotificationCount() const { return notification_count_; }
+
+  std::deque<base::TestPendingTask> TakePendingTasks() {
+    std::deque<base::TestPendingTask> tasks = task_runner_->GetPendingTasks();
+    task_runner_->ClearPendingTasks();
+    return tasks;
+  }
+
+ protected:
+  int notification_count_;
+  scoped_refptr<base::TestSimpleTaskRunner> task_runner_;
+};
+
+TEST_F(DelayedUniqueNotifierTest, ZeroDelay) {
+  base::TimeDelta delay = base::TimeDelta::FromInternalValue(0);
+  TestNotifier notifier(
+      task_runner_,
+      base::Bind(&DelayedUniqueNotifierTest::Notify, base::Unretained(this)),
+      delay);
+
+  EXPECT_EQ(0, NotificationCount());
+
+  // Basic schedule for |delay| from now.
+  base::TimeTicks schedule_time =
+      base::TimeTicks() + base::TimeDelta::FromInternalValue(10);
+
+  notifier.SetNow(schedule_time);
+  notifier.Schedule();
+
+  std::deque<base::TestPendingTask> tasks = TakePendingTasks();
+  ASSERT_EQ(1u, tasks.size());
+  EXPECT_EQ(base::TimeTicks() + delay, tasks[0].GetTimeToRun());
+
+  tasks[0].task.Run();
+  EXPECT_EQ(1, NotificationCount());
+
+  // 5 schedules should result in only one run.
+  for (int i = 0; i < 5; ++i)
+    notifier.Schedule();
+
+  tasks = TakePendingTasks();
+  ASSERT_EQ(1u, tasks.size());
+  EXPECT_EQ(base::TimeTicks() + delay, tasks[0].GetTimeToRun());
+
+  tasks[0].task.Run();
+  EXPECT_EQ(2, NotificationCount());
+}
+
+TEST_F(DelayedUniqueNotifierTest, SmallDelay) {
+  base::TimeDelta delay = base::TimeDelta::FromInternalValue(20);
+  TestNotifier notifier(
+      task_runner_,
+      base::Bind(&DelayedUniqueNotifierTest::Notify, base::Unretained(this)),
+      delay);
+
+  EXPECT_EQ(0, NotificationCount());
+
+  // Basic schedule for |delay| from now (now: 30, run time: 50).
+  base::TimeTicks schedule_time =
+      base::TimeTicks() + base::TimeDelta::FromInternalValue(30);
+
+  notifier.SetNow(schedule_time);
+  notifier.Schedule();
+
+  std::deque<base::TestPendingTask> tasks = TakePendingTasks();
+
+  ASSERT_EQ(1u, tasks.size());
+  EXPECT_EQ(base::TimeTicks() + delay, tasks[0].GetTimeToRun());
+
+  // It's not yet time to run, so we expect no notifications.
+  tasks[0].task.Run();
+  EXPECT_EQ(0, NotificationCount());
+
+  tasks = TakePendingTasks();
+
+  ASSERT_EQ(1u, tasks.size());
+  // Now the time should be delay minus whatever the value of now happens to be
+  // (now: 30, run time: 50).
+  base::TimeTicks scheduled_run_time = notifier.Now() + delay;
+  base::TimeTicks scheduled_delay =
+      base::TimeTicks() + (scheduled_run_time - notifier.Now());
+  EXPECT_EQ(scheduled_delay, tasks[0].GetTimeToRun());
+
+  // Move closer to the run time (time: 49, run time: 50).
+  notifier.SetNow(notifier.Now() + base::TimeDelta::FromInternalValue(19));
+
+  // It's not yet time to run, so we expect no notifications.
+  tasks[0].task.Run();
+  EXPECT_EQ(0, NotificationCount());
+
+  tasks = TakePendingTasks();
+  ASSERT_EQ(1u, tasks.size());
+
+  // Now the time should be delay minus whatever the value of now happens to be.
+  scheduled_delay = base::TimeTicks() + (scheduled_run_time - notifier.Now());
+  EXPECT_EQ(scheduled_delay, tasks[0].GetTimeToRun());
+
+  // Move to exactly the run time (time: 50, run time: 50).
+  notifier.SetNow(notifier.Now() + base::TimeDelta::FromInternalValue(1));
+
+  // It's time to run!
+  tasks[0].task.Run();
+  EXPECT_EQ(1, NotificationCount());
+
+  tasks = TakePendingTasks();
+  EXPECT_EQ(0u, tasks.size());
+}
+
+TEST_F(DelayedUniqueNotifierTest, RescheduleDelay) {
+  base::TimeDelta delay = base::TimeDelta::FromInternalValue(20);
+  TestNotifier notifier(
+      task_runner_,
+      base::Bind(&DelayedUniqueNotifierTest::Notify, base::Unretained(this)),
+      delay);
+
+  base::TimeTicks schedule_time;
+  // Move time 19 units forward and reschedule, expecting that we still need to
+  // run in |delay| time and we don't get a notification.
+  for (int i = 0; i < 10; ++i) {
+    EXPECT_EQ(0, NotificationCount());
+
+    // Move time forward 19 units.
+    schedule_time = notifier.Now() + base::TimeDelta::FromInternalValue(19);
+    notifier.SetNow(schedule_time);
+    notifier.Schedule();
+
+    std::deque<base::TestPendingTask> tasks = TakePendingTasks();
+
+    ASSERT_EQ(1u, tasks.size());
+    EXPECT_EQ(base::TimeTicks() + delay, tasks[0].GetTimeToRun());
+
+    // It's not yet time to run, so we expect no notifications.
+    tasks[0].task.Run();
+    EXPECT_EQ(0, NotificationCount());
+  }
+
+  // Move time forward 20 units, expecting a notification.
+  schedule_time = notifier.Now() + base::TimeDelta::FromInternalValue(20);
+  notifier.SetNow(schedule_time);
+
+  std::deque<base::TestPendingTask> tasks = TakePendingTasks();
+
+  ASSERT_EQ(1u, tasks.size());
+  EXPECT_EQ(base::TimeTicks() + delay, tasks[0].GetTimeToRun());
+
+  // Time to run!
+  tasks[0].task.Run();
+  EXPECT_EQ(1, NotificationCount());
+}
+
+TEST_F(DelayedUniqueNotifierTest, Cancel) {

[reveman, 2014/05/28 19:50:02]

As part of this test, can you add a simple check to ensure that repeatedly
calling Schedule() and Cancel() doesn't cause more pending tasks to be added.

[vmpstr, 2014/05/28 20:17:13]

Done.

+  base::TimeDelta delay = base::TimeDelta::FromInternalValue(20);
+  TestNotifier notifier(
+      task_runner_,
+      base::Bind(&DelayedUniqueNotifierTest::Notify, base::Unretained(this)),
+      delay);
+
+  EXPECT_EQ(0, NotificationCount());
+
+  // Schedule for |delay| seconds from now.
+  base::TimeTicks schedule_time =
+      notifier.Now() + base::TimeDelta::FromInternalValue(10);
+  notifier.SetNow(schedule_time);
+  notifier.Schedule();
+
+  // Cancel the run.
+  notifier.Cancel();
+
+  std::deque<base::TestPendingTask> tasks = TakePendingTasks();
+
+  ASSERT_EQ(1u, tasks.size());
+  EXPECT_EQ(base::TimeTicks() + delay, tasks[0].GetTimeToRun());
+
+  // Time to run, but a canceled task!
+  tasks[0].task.Run();
+  EXPECT_EQ(0, NotificationCount());
+
+  tasks = TakePendingTasks();
+  EXPECT_EQ(0u, tasks.size());
+}
+
+}  // namespace
+}  // namespace cc