gecko/widget/windows/nsAppShell.cpp
Robert O'Callahan 01ff4ed652 Bug 905405. Wrap mLastNativeEventScheduled in a mutex to avoid racing on it. r=bsmedberg
--HG--
extra : rebase_source : 769e8870f4bf33407d01d944d8969459b9a161ce
2013-09-19 16:24:34 +12:00

257 lines
8.5 KiB
C++

/* -*- 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/RPCChannel.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"
using namespace mozilla;
using namespace mozilla::widget;
namespace mozilla {
namespace widget {
// Native event callback message.
UINT sAppShellGeckoMsgId = RegisterWindowMessageW(L"nsAppShell:EventID");
} }
const PRUnichar* 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();
sTaskbarButtonCreatedMsg = ::RegisterWindowMessageW(kTaskbarButtonEventId);
NS_ASSERTION(sTaskbarButtonCreatedMsg, "Could not register taskbar button creation message");
WNDCLASSW wc;
HINSTANCE module = GetModuleHandle(NULL);
const PRUnichar *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 = NULL;
wc.hCursor = NULL;
wc.hbrBackground = (HBRUSH) NULL;
wc.lpszMenuName = (LPCWSTR) NULL;
wc.lpszClassName = kWindowClass;
RegisterClassW(&wc);
}
mEventWnd = CreateWindowW(kWindowClass, L"nsAppShell:EventWindow",
0, 0, 0, 10, 10, NULL, NULL, module, NULL);
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();
nsresult rv = nsBaseAppShell::Run();
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::RPCChannel::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, NULL, 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, NULL, 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();
WinUtils::WaitForMessage();
}
} 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;
}