cc: Add UniqueNotifier to cc/base.

cc/base/unique_notifier_unittest.cc

+// 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 "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/message_loop/message_loop_proxy.h"
+#include "base/run_loop.h"
+#include "base/single_thread_task_runner.h"
+#include "cc/base/unique_notifier.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace cc {
+namespace {
+
+class UniqueNotifierTest : public testing::Test {
+ public:
+  UniqueNotifierTest() : notification_count_(0) {}
+
+  virtual void SetUp() OVERRIDE {
+    task_runner_ = base::MessageLoopProxy::current();
+    ResetNotificationCount();
+  }
+
+  virtual void TearDown() OVERRIDE {
+    notifier_.reset();
+    task_runner_ = NULL;
+  }
+
+  void Notify() { ++notification_count_; }
+
+  int NotificationCount() const { return notification_count_; }
+
+  void ResetNotificationCount() { notification_count_ = 0; }
+
+  void RunForTime(base::TimeDelta delay) {
+    run_loop_ = make_scoped_ptr(new base::RunLoop);
+    task_runner_->PostDelayedTask(FROM_HERE, run_loop_->QuitClosure(), delay);
+    run_loop_->Run();
+  }
+
+ protected:
+  int notification_count_;
+  scoped_ptr<UniqueNotifier> notifier_;
+  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
+  scoped_ptr<base::RunLoop> run_loop_;
+};
+
+TEST_F(UniqueNotifierTest, ZeroDelay) {
+  notifier_ = make_scoped_ptr(new UniqueNotifier(
+      task_runner_.get(),
+      base::Bind(&UniqueNotifierTest::Notify, base::Unretained(this)),
+      base::TimeDelta()));
+
+  EXPECT_EQ(0, NotificationCount());
+
+  // Basic schedule should result in a run.
+  notifier_->Schedule();
+
+  RunForTime(base::TimeDelta());
+  EXPECT_EQ(1, NotificationCount());
+
+  // Multiple schedules should only result in one run.
+  for (int i = 0; i < 5; ++i)
+    notifier_->Schedule();
+
+  RunForTime(base::TimeDelta());
+  EXPECT_EQ(2, NotificationCount());
+
+  // Schedule and notifier going away should not result in any runs.
+  notifier_->Schedule();
+  notifier_.reset();
+
+  RunForTime(base::TimeDelta());
+  EXPECT_EQ(2, NotificationCount());
+}
+
+TEST_F(UniqueNotifierTest, SecondDelay) {
+  notifier_ = make_scoped_ptr(new UniqueNotifier(
+      task_runner_.get(),
+      base::Bind(&UniqueNotifierTest::Notify, base::Unretained(this)),
+      base::TimeDelta::FromSeconds(1)));
+
+  EXPECT_EQ(0, NotificationCount());
+
+  // Basic schedule for 1 second from now.
+  notifier_->Schedule();
+
+  // Half a second passed, we should have no runs.
+  RunForTime(base::TimeDelta::FromMilliseconds(500));
+  EXPECT_EQ(0, NotificationCount());
+
+  // After another 0.6 seconds, we should get a run.
+  RunForTime(base::TimeDelta::FromMilliseconds(600));
+  EXPECT_EQ(1, NotificationCount());
+
+  // 5 schedules should result in only one run.
+  for (int i = 0; i < 5; ++i)
+    notifier_->Schedule();
+
+  RunForTime(base::TimeDelta::FromMilliseconds(1100));
+  EXPECT_EQ(2, NotificationCount());
+}
+
+TEST_F(UniqueNotifierTest, RescheduleDelay) {
+  notifier_ = make_scoped_ptr(new UniqueNotifier(
+      task_runner_.get(),
+      base::Bind(&UniqueNotifierTest::Notify, base::Unretained(this)),
+      base::TimeDelta::FromSeconds(1)));
+
+  EXPECT_EQ(0, NotificationCount());
+
+  // Schedule for 1 second from now.
+  notifier_->Schedule();
+
+  // Half a second later, we should have no runs.
+  RunForTime(base::TimeDelta::FromMilliseconds(500));
+  EXPECT_EQ(0, NotificationCount());
+
+  // Reschedule for an extra second.
+  notifier_->Schedule();
+
+  // Half a second later, we should have no runs.
+  RunForTime(base::TimeDelta::FromMilliseconds(500));
+  EXPECT_EQ(0, NotificationCount());
+
+  // Reschedule for an extra second.
+  notifier_->Schedule();
+
+  // Half a second later, we should have no runs.
+  RunForTime(base::TimeDelta::FromMilliseconds(500));
+  EXPECT_EQ(0, NotificationCount());
+
+  // After another 0.6 seconds, we should get a run.
+  RunForTime(base::TimeDelta::FromMilliseconds(600));
+  EXPECT_EQ(1, NotificationCount());
+}
+
+}  // namespace
+}  // namespace cc