Refactor: Simplify WaitableEventWatcher.

base/synchronization/waitable_event_watcher_unittest.cc

 // Copyright (c) 2012 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/callback.h"
 #include "base/message_loop.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/synchronization/waitable_event_watcher.h"
 #include "base/threading/platform_thread.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace base {
 
 namespace {
 
 // The message loops on which each waitable event timer should be tested.
 const MessageLoop::Type testing_message_loops[] = {
   MessageLoop::TYPE_DEFAULT,
   MessageLoop::TYPE_IO,
 #if !defined(OS_IOS)  // iOS does not allow direct running of the UI loop.
   MessageLoop::TYPE_UI,
 #endif
 };
 
 const int kNumTestingMessageLoops = arraysize(testing_message_loops);
 
-class QuitDelegate : public WaitableEventWatcher::Delegate {
+void QuitWhenSignaled(WaitableEvent* event) {
+  MessageLoop::current()->QuitWhenIdle();
+}
+
+class DecrementCountContainer {
  public:
-  virtual void OnWaitableEventSignaled(WaitableEvent* event) OVERRIDE {
-    MessageLoop::current()->QuitWhenIdle();
+  explicit DecrementCountContainer(int* counter) : counter_(counter) {
   }
-};
-
-class DecrementCountDelegate : public WaitableEventWatcher::Delegate {
- public:
-  explicit DecrementCountDelegate(int* counter) : counter_(counter) {
-  }
-  virtual void OnWaitableEventSignaled(WaitableEvent* object) OVERRIDE {
+  void OnWaitableEventSignaled(WaitableEvent* object) {
     --(*counter_);
   }
  private:
   int* counter_;
 };
 
 void RunTest_BasicSignal(MessageLoop::Type message_loop_type) {
   MessageLoop message_loop(message_loop_type);
 
   // A manual-reset event that is not yet signaled.
   WaitableEvent event(true, false);
 
   WaitableEventWatcher watcher;
   EXPECT_TRUE(watcher.GetWatchedEvent() == NULL);
 
-  QuitDelegate delegate;
-  watcher.StartWatching(&event, &delegate);
+  Callback<void(WaitableEvent*)> quit_callback = Bind(&QuitWhenSignaled);
+  watcher.StartWatching(&event, &quit_callback);
   EXPECT_EQ(&event, watcher.GetWatchedEvent());
 
   event.Signal();
 
   MessageLoop::current()->Run();
 
   EXPECT_TRUE(watcher.GetWatchedEvent() == NULL);
 }
 
 void RunTest_BasicCancel(MessageLoop::Type message_loop_type) {
   MessageLoop message_loop(message_loop_type);
 
   // A manual-reset event that is not yet signaled.
   WaitableEvent event(true, false);
 
   WaitableEventWatcher watcher;
 
-  QuitDelegate delegate;
-  watcher.StartWatching(&event, &delegate);
+  Callback<void(WaitableEvent*)> quit_callback = Bind(&QuitWhenSignaled);
+  watcher.StartWatching(&event, &quit_callback);
 
   watcher.StopWatching();
 }
 
 void RunTest_CancelAfterSet(MessageLoop::Type message_loop_type) {
   MessageLoop message_loop(message_loop_type);
 
   // A manual-reset event that is not yet signaled.
   WaitableEvent event(true, false);
 
   WaitableEventWatcher watcher;
 
   int counter = 1;
-  DecrementCountDelegate delegate(&counter);
-
-  watcher.StartWatching(&event, &delegate);
+  DecrementCountContainer delegate(&counter);
+  Callback<void(WaitableEvent*)> callback =
+      Bind(&DecrementCountContainer::OnWaitableEventSignaled,
+           Unretained(&delegate));
+  watcher.StartWatching(&event, &callback);
 
   event.Signal();
 
   // Let the background thread do its business
   base::PlatformThread::Sleep(base::TimeDelta::FromMilliseconds(30));
 
   watcher.StopWatching();
 
   MessageLoop::current()->RunUntilIdle();
 
   // Our delegate should not have fired.
   EXPECT_EQ(1, counter);
 }
 
 void RunTest_OutlivesMessageLoop(MessageLoop::Type message_loop_type) {
   // Simulate a MessageLoop that dies before an WaitableEventWatcher.  This
   // ordinarily doesn't happen when people use the Thread class, but it can
   // happen when people use the Singleton pattern or atexit.
   WaitableEvent event(true, false);
   {
     WaitableEventWatcher watcher;
     {
       MessageLoop message_loop(message_loop_type);
 
-      QuitDelegate delegate;
-      watcher.StartWatching(&event, &delegate);
+      Callback<void(WaitableEvent*)> quit_callback = Bind(&QuitWhenSignaled);
+      watcher.StartWatching(&event, &quit_callback);
     }
   }
 }
 
 void RunTest_DeleteUnder(MessageLoop::Type message_loop_type) {
   // Delete the WaitableEvent out from under the Watcher. This is explictly
   // allowed by the interface.
 
   MessageLoop message_loop(message_loop_type);
 
   {
     WaitableEventWatcher watcher;
 
     WaitableEvent* event = new WaitableEvent(false, false);
-    QuitDelegate delegate;
-    watcher.StartWatching(event, &delegate);
+
+    Callback<void(WaitableEvent*)> quit_callback = Bind(&QuitWhenSignaled);
+    watcher.StartWatching(event, &quit_callback);
     delete event;
   }
 }
 
 }  // namespace
 
 //-----------------------------------------------------------------------------
 
 TEST(WaitableEventWatcherTest, BasicSignal) {
   for (int i = 0; i < kNumTestingMessageLoops; i++) {
@@ skipping 25 matching lines @@
 #else
 #define MAYBE_DeleteUnder DeleteUnder
 #endif
 TEST(WaitableEventWatcherTest, MAYBE_DeleteUnder) {
   for (int i = 0; i < kNumTestingMessageLoops; i++) {
     RunTest_DeleteUnder(testing_message_loops[i]);
   }
 }
 
 }  // namespace base