diff -r 000000000000 -r 6474c204b198 widget/windows/nsAppShell.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/widget/windows/nsAppShell.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,337 @@
+/* -*- Mode: c++; tab-width: 2; indent-tabs-mode: nil; -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/ipc/MessageChannel.h"
+#include "mozilla/ipc/WindowsMessageLoop.h"
+#include "nsAppShell.h"
+#include "nsToolkit.h"
+#include "nsThreadUtils.h"
+#include "WinUtils.h"
+#include "WinTaskbar.h"
+#include "WinMouseScrollHandler.h"
+#include "nsWindowDefs.h"
+#include "nsString.h"
+#include "WinIMEHandler.h"
+#include "mozilla/widget/AudioSession.h"
+#include "mozilla/HangMonitor.h"
+#include "nsIDOMWakeLockListener.h"
+#include "nsIPowerManagerService.h"
+#include "mozilla/StaticPtr.h"
+#include "nsTHashtable.h"
+#include "nsHashKeys.h"
+#include "GeckoProfiler.h"
+
+using namespace mozilla;
+using namespace mozilla::widget;
+
+// A wake lock listener that disables screen saver when requested by
+// Gecko. For example when we're playing video in a foreground tab we
+// don't want the screen saver to turn on.
+class WinWakeLockListener : public nsIDOMMozWakeLockListener {
+public:
+  NS_DECL_ISUPPORTS;
+
+private:
+  NS_IMETHOD Callback(const nsAString& aTopic, const nsAString& aState) {
+    bool isLocked = mLockedTopics.Contains(aTopic);
+    bool shouldLock = aState.Equals(NS_LITERAL_STRING("locked-foreground"));
+    if (isLocked == shouldLock) {
+      return NS_OK;
+    }
+    if (shouldLock) {
+      if (!mLockedTopics.Count()) {
+        // This is the first topic to request the screen saver be disabled.
+        // Prevent screen saver.
+        SetThreadExecutionState(ES_DISPLAY_REQUIRED|ES_CONTINUOUS);
+      }
+      mLockedTopics.PutEntry(aTopic);
+    } else {
+      mLockedTopics.RemoveEntry(aTopic);
+      if (!mLockedTopics.Count()) {
+        // No other outstanding topics have requested screen saver be disabled.
+        // Re-enable screen saver.
+        SetThreadExecutionState(ES_CONTINUOUS);
+      }
+   }
+    return NS_OK;
+  }
+
+  // Keep track of all the topics that have requested a wake lock. When the
+  // number of topics in the hashtable reaches zero, we can uninhibit the
+  // screensaver again.
+  nsTHashtable<nsStringHashKey> mLockedTopics;
+};
+
+NS_IMPL_ISUPPORTS(WinWakeLockListener, nsIDOMMozWakeLockListener)
+StaticRefPtr<WinWakeLockListener> sWakeLockListener;
+
+static void
+AddScreenWakeLockListener()
+{
+  nsCOMPtr<nsIPowerManagerService> sPowerManagerService = do_GetService(POWERMANAGERSERVICE_CONTRACTID);
+  if (sPowerManagerService) {
+    sWakeLockListener = new WinWakeLockListener();
+    sPowerManagerService->AddWakeLockListener(sWakeLockListener);
+  } else {
+    NS_WARNING("Failed to retrieve PowerManagerService, wakelocks will be broken!");
+  }
+}
+
+static void
+RemoveScreenWakeLockListener()
+{
+  nsCOMPtr<nsIPowerManagerService> sPowerManagerService = do_GetService(POWERMANAGERSERVICE_CONTRACTID);
+  if (sPowerManagerService) {
+    sPowerManagerService->RemoveWakeLockListener(sWakeLockListener);
+    sPowerManagerService = nullptr;
+    sWakeLockListener = nullptr;
+  }
+}
+
+namespace mozilla {
+namespace widget {
+// Native event callback message.
+UINT sAppShellGeckoMsgId = RegisterWindowMessageW(L"nsAppShell:EventID");
+} }
+
+const wchar_t* kTaskbarButtonEventId = L"TaskbarButtonCreated";
+UINT sTaskbarButtonCreatedMsg;
+
+/* static */
+UINT nsAppShell::GetTaskbarButtonCreatedMessage() {
+	return sTaskbarButtonCreatedMsg;
+}
+
+namespace mozilla {
+namespace crashreporter {
+void LSPAnnotate();
+} // namespace crashreporter
+} // namespace mozilla
+
+using mozilla::crashreporter::LSPAnnotate;
+
+//-------------------------------------------------------------------------
+
+/*static*/ LRESULT CALLBACK
+nsAppShell::EventWindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
+{
+  if (uMsg == sAppShellGeckoMsgId) {
+    nsAppShell *as = reinterpret_cast<nsAppShell *>(lParam);
+    as->NativeEventCallback();
+    NS_RELEASE(as);
+    return TRUE;
+  }
+  return DefWindowProc(hwnd, uMsg, wParam, lParam);
+}
+
+nsAppShell::~nsAppShell()
+{
+  if (mEventWnd) {
+    // DestroyWindow doesn't do anything when called from a non UI thread.
+    // Since mEventWnd was created on the UI thread, it must be destroyed on
+    // the UI thread.
+    SendMessage(mEventWnd, WM_CLOSE, 0, 0);
+  }
+}
+
+nsresult
+nsAppShell::Init()
+{
+#ifdef MOZ_CRASHREPORTER
+  LSPAnnotate();
+#endif
+
+  mLastNativeEventScheduled = TimeStamp::NowLoRes();
+
+  mozilla::ipc::windows::InitUIThread();
+
+  sTaskbarButtonCreatedMsg = ::RegisterWindowMessageW(kTaskbarButtonEventId);
+  NS_ASSERTION(sTaskbarButtonCreatedMsg, "Could not register taskbar button creation message");
+
+  WNDCLASSW wc;
+  HINSTANCE module = GetModuleHandle(nullptr);
+
+  const wchar_t *const kWindowClass = L"nsAppShell:EventWindowClass";
+  if (!GetClassInfoW(module, kWindowClass, &wc)) {
+    wc.style         = 0;
+    wc.lpfnWndProc   = EventWindowProc;
+    wc.cbClsExtra    = 0;
+    wc.cbWndExtra    = 0;
+    wc.hInstance     = module;
+    wc.hIcon         = nullptr;
+    wc.hCursor       = nullptr;
+    wc.hbrBackground = (HBRUSH) nullptr;
+    wc.lpszMenuName  = (LPCWSTR) nullptr;
+    wc.lpszClassName = kWindowClass;
+    RegisterClassW(&wc);
+  }
+
+  mEventWnd = CreateWindowW(kWindowClass, L"nsAppShell:EventWindow",
+                           0, 0, 0, 10, 10, nullptr, nullptr, module, nullptr);
+  NS_ENSURE_STATE(mEventWnd);
+
+  return nsBaseAppShell::Init();
+}
+
+NS_IMETHODIMP
+nsAppShell::Run(void)
+{
+  // Ignore failure; failing to start the application is not exactly an
+  // appropriate response to failing to start an audio session.
+  mozilla::widget::StartAudioSession();
+
+  // Add an observer that disables the screen saver when requested by Gecko.
+  // For example when we're playing video in the foreground tab.
+  AddScreenWakeLockListener();
+
+  nsresult rv = nsBaseAppShell::Run();
+
+  RemoveScreenWakeLockListener();
+
+  mozilla::widget::StopAudioSession();
+
+  return rv;
+}
+
+NS_IMETHODIMP
+nsAppShell::Exit(void)
+{
+  return nsBaseAppShell::Exit();
+}
+
+void
+nsAppShell::DoProcessMoreGeckoEvents()
+{
+  // Called by nsBaseAppShell's NativeEventCallback() after it has finished
+  // processing pending gecko events and there are still gecko events pending
+  // for the thread. (This can happen if NS_ProcessPendingEvents reached it's
+  // starvation timeout limit.) The default behavior in nsBaseAppShell is to
+  // call ScheduleNativeEventCallback to post a follow up native event callback
+  // message. This triggers an additional call to NativeEventCallback for more
+  // gecko event processing.
+
+  // There's a deadlock risk here with certain internal Windows modal loops. In
+  // our dispatch code, we prioritize messages so that input is handled first.
+  // However Windows modal dispatch loops often prioritize posted messages. If
+  // we find ourselves in a tight gecko timer loop where NS_ProcessPendingEvents
+  // takes longer than the timer duration, NS_HasPendingEvents(thread) will
+  // always be true. ScheduleNativeEventCallback will be called on every
+  // NativeEventCallback callback, and in a Windows modal dispatch loop, the
+  // callback message will be processed first -> input gets starved, dead lock.
+
+  // To avoid, don't post native callback messages from NativeEventCallback
+  // when we're in a modal loop. This gets us back into the Windows modal
+  // dispatch loop dispatching input messages. Once we drop out of the modal
+  // loop, we use mNativeCallbackPending to fire off a final NativeEventCallback
+  // if we need it, which insures NS_ProcessPendingEvents gets called and all
+  // gecko events get processed.
+  if (mEventloopNestingLevel < 2) {
+    OnDispatchedEvent(nullptr);
+    mNativeCallbackPending = false;
+  } else {
+    mNativeCallbackPending = true;
+  }
+}
+
+void
+nsAppShell::ScheduleNativeEventCallback()
+{
+  // Post a message to the hidden message window
+  NS_ADDREF_THIS(); // will be released when the event is processed
+  {
+    MutexAutoLock lock(mLastNativeEventScheduledMutex);
+    // Time stamp this event so we can detect cases where the event gets
+    // dropping in sub classes / modal loops we do not control.
+    mLastNativeEventScheduled = TimeStamp::NowLoRes();
+  }
+  ::PostMessage(mEventWnd, sAppShellGeckoMsgId, 0, reinterpret_cast<LPARAM>(this));
+}
+
+bool
+nsAppShell::ProcessNextNativeEvent(bool mayWait)
+{
+  // Notify ipc we are spinning a (possibly nested) gecko event loop.
+  mozilla::ipc::MessageChannel::NotifyGeckoEventDispatch();
+
+  bool gotMessage = false;
+
+  do {
+    MSG msg;
+    bool uiMessage = false;
+
+    // For avoiding deadlock between our process and plugin process by
+    // mouse wheel messages, we're handling actually when we receive one of
+    // following internal messages which is posted by native mouse wheel
+    // message handler. Any other events, especially native modifier key
+    // events, should not be handled between native message and posted
+    // internal message because it may make different modifier key state or
+    // mouse cursor position between them.
+    if (mozilla::widget::MouseScrollHandler::IsWaitingInternalMessage()) {
+      gotMessage = WinUtils::PeekMessage(&msg, nullptr, MOZ_WM_MOUSEWHEEL_FIRST,
+                                         MOZ_WM_MOUSEWHEEL_LAST, PM_REMOVE);
+      NS_ASSERTION(gotMessage,
+                   "waiting internal wheel message, but it has not come");
+      uiMessage = gotMessage;
+    }
+
+    if (!gotMessage) {
+      gotMessage = WinUtils::PeekMessage(&msg, nullptr, 0, 0, PM_REMOVE);
+      uiMessage =
+        (msg.message >= WM_KEYFIRST && msg.message <= WM_IME_KEYLAST) ||
+        (msg.message >= NS_WM_IMEFIRST && msg.message <= NS_WM_IMELAST) ||
+        (msg.message >= WM_MOUSEFIRST && msg.message <= WM_MOUSELAST);
+    }
+
+    if (gotMessage) {
+      if (msg.message == WM_QUIT) {
+        ::PostQuitMessage(msg.wParam);
+        Exit();
+      } else {
+        // If we had UI activity we would be processing it now so we know we
+        // have either kUIActivity or kActivityNoUIAVail.
+        mozilla::HangMonitor::NotifyActivity(
+          uiMessage ? mozilla::HangMonitor::kUIActivity :
+                      mozilla::HangMonitor::kActivityNoUIAVail);
+
+        if (msg.message >= WM_KEYFIRST && msg.message <= WM_KEYLAST &&
+            IMEHandler::ProcessRawKeyMessage(msg)) {
+          continue;  // the message is consumed.
+        }
+
+        ::TranslateMessage(&msg);
+        ::DispatchMessageW(&msg);
+      }
+    } else if (mayWait) {
+      // Block and wait for any posted application message
+      mozilla::HangMonitor::Suspend();
+      {
+        GeckoProfilerSleepRAII profiler_sleep;
+        ::WaitMessage();
+      }
+    }
+  } while (!gotMessage && mayWait);
+
+  // See DoProcessNextNativeEvent, mEventloopNestingLevel will be
+  // one when a modal loop unwinds.
+  if (mNativeCallbackPending && mEventloopNestingLevel == 1)
+    DoProcessMoreGeckoEvents();
+
+  // Check for starved native callbacks. If we haven't processed one
+  // of these events in NATIVE_EVENT_STARVATION_LIMIT, fire one off.
+  static const mozilla::TimeDuration nativeEventStarvationLimit =
+    mozilla::TimeDuration::FromSeconds(NATIVE_EVENT_STARVATION_LIMIT);
+
+  TimeDuration timeSinceLastNativeEventScheduled;
+  {
+    MutexAutoLock lock(mLastNativeEventScheduledMutex);
+    timeSinceLastNativeEventScheduled =
+        TimeStamp::NowLoRes() - mLastNativeEventScheduled;
+  }
+  if (timeSinceLastNativeEventScheduled > nativeEventStarvationLimit) {
+    ScheduleNativeEventCallback();
+  }
+
+  return gotMessage;
+}