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/* -*- 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/Attributes.h"
#include "mozilla/ScopeExit.h"
#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 "nsWindow.h"
#include "nsString.h"
#include "WinIMEHandler.h"
#include "mozilla/widget/AudioSession.h"
#include "mozilla/BackgroundHangMonitor.h"
#include "mozilla/Hal.h"
#include "nsIDOMWakeLockListener.h"
#include "nsIPowerManagerService.h"
#include "mozilla/ProfilerLabels.h"
#include "mozilla/StaticPtr.h"
#include "nsTHashtable.h"
#include "nsHashKeys.h"
#include "nsComponentManagerUtils.h"
#include "ScreenHelperWin.h"
#include "HeadlessScreenHelper.h"
#include "mozilla/widget/ScreenManager.h"
#include "mozilla/Atomics.h"
#include "mozilla/NativeNt.h"
#include "mozilla/WindowsDiagnostics.h"
#include "mozilla/WindowsProcessMitigations.h"
#include <winternl.h>
#ifdef MOZ_BACKGROUNDTASKS
# include "mozilla/BackgroundTasks.h"
#endif
#if defined(ACCESSIBILITY)
# include "mozilla/a11y/Compatibility.h"
# include "mozilla/a11y/Platform.h"
#endif // defined(ACCESSIBILITY)
using namespace mozilla;
using namespace mozilla::widget;
#define WAKE_LOCK_LOG(...) \
MOZ_LOG(gWinWakeLockLog, mozilla::LogLevel::Debug, (__VA_ARGS__))
static mozilla::LazyLogModule gWinWakeLockLog("WinWakeLock");
// This wakelock listener is used for Window7 and above.
class WinWakeLockListener final : public nsIDOMMozWakeLockListener {
public:
NS_DECL_ISUPPORTS
WinWakeLockListener() { MOZ_ASSERT(XRE_IsParentProcess()); }
private:
~WinWakeLockListener() {
ReleaseWakelockIfNeeded(PowerRequestDisplayRequired);
ReleaseWakelockIfNeeded(PowerRequestExecutionRequired);
}
void SetHandle(HANDLE aHandle, POWER_REQUEST_TYPE aType) {
switch (aType) {
case PowerRequestDisplayRequired: {
if (!aHandle && mDisplayHandle) {
CloseHandle(mDisplayHandle);
}
mDisplayHandle = aHandle;
return;
}
case PowerRequestExecutionRequired: {
if (!aHandle && mNonDisplayHandle) {
CloseHandle(mNonDisplayHandle);
}
mNonDisplayHandle = aHandle;
return;
}
default:
MOZ_ASSERT_UNREACHABLE("Invalid request type");
return;
}
}
HANDLE GetHandle(POWER_REQUEST_TYPE aType) const {
switch (aType) {
case PowerRequestDisplayRequired:
return mDisplayHandle;
case PowerRequestExecutionRequired:
return mNonDisplayHandle;
default:
MOZ_ASSERT_UNREACHABLE("Invalid request type");
return nullptr;
}
}
HANDLE CreateHandle(POWER_REQUEST_TYPE aType) {
MOZ_ASSERT(!GetHandle(aType));
REASON_CONTEXT context = {0};
context.Version = POWER_REQUEST_CONTEXT_VERSION;
context.Flags = POWER_REQUEST_CONTEXT_SIMPLE_STRING;
context.Reason.SimpleReasonString = RequestTypeLPWSTR(aType);
HANDLE handle = PowerCreateRequest(&context);
if (!handle) {
WAKE_LOCK_LOG("Failed to create handle for %s, error=%lu",
RequestTypeStr(aType), GetLastError());
return nullptr;
}
SetHandle(handle, aType);
return handle;
}
LPWSTR RequestTypeLPWSTR(POWER_REQUEST_TYPE aType) const {
switch (aType) {
case PowerRequestDisplayRequired:
return const_cast<LPWSTR>(L"display request"); // -Wwritable-strings
case PowerRequestExecutionRequired:
return const_cast<LPWSTR>(
L"non-display request"); // -Wwritable-strings
default:
MOZ_ASSERT_UNREACHABLE("Invalid request type");
return const_cast<LPWSTR>(L"unknown"); // -Wwritable-strings
}
}
const char* RequestTypeStr(POWER_REQUEST_TYPE aType) const {
switch (aType) {
case PowerRequestDisplayRequired:
return "display request";
case PowerRequestExecutionRequired:
return "non-display request";
default:
MOZ_ASSERT_UNREACHABLE("Invalid request type");
return "unknown";
}
}
void RequestWakelockIfNeeded(POWER_REQUEST_TYPE aType) {
if (GetHandle(aType)) {
WAKE_LOCK_LOG("Already requested lock for %s", RequestTypeStr(aType));
return;
}
WAKE_LOCK_LOG("Prepare a wakelock for %s", RequestTypeStr(aType));
HANDLE handle = CreateHandle(aType);
if (!handle) {
WAKE_LOCK_LOG("Failed due to no handle for %s", RequestTypeStr(aType));
return;
}
if (PowerSetRequest(handle, aType)) {
WAKE_LOCK_LOG("Requested %s lock", RequestTypeStr(aType));
} else {
WAKE_LOCK_LOG("Failed to request %s lock, error=%lu",
RequestTypeStr(aType), GetLastError());
SetHandle(nullptr, aType);
}
}
void ReleaseWakelockIfNeeded(POWER_REQUEST_TYPE aType) {
if (!GetHandle(aType)) {
WAKE_LOCK_LOG("Already released lock for %s", RequestTypeStr(aType));
return;
}
WAKE_LOCK_LOG("Prepare to release wakelock for %s", RequestTypeStr(aType));
if (!PowerClearRequest(GetHandle(aType), aType)) {
WAKE_LOCK_LOG("Failed to release %s lock, error=%lu",
RequestTypeStr(aType), GetLastError());
return;
}
SetHandle(nullptr, aType);
WAKE_LOCK_LOG("Released wakelock for %s", RequestTypeStr(aType));
}
NS_IMETHOD Callback(const nsAString& aTopic,
const nsAString& aState) override {
WAKE_LOCK_LOG("topic=%s, state=%s", NS_ConvertUTF16toUTF8(aTopic).get(),
NS_ConvertUTF16toUTF8(aState).get());
if (!aTopic.EqualsASCII("screen") && !aTopic.EqualsASCII("audio-playing") &&
!aTopic.EqualsASCII("video-playing")) {
return NS_OK;
}
const bool isNonDisplayLock = aTopic.EqualsASCII("audio-playing");
bool requestLock = false;
if (isNonDisplayLock) {
requestLock = aState.EqualsASCII("locked-foreground") ||
aState.EqualsASCII("locked-background");
} else {
requestLock = aState.EqualsASCII("locked-foreground");
}
if (isNonDisplayLock) {
if (requestLock) {
RequestWakelockIfNeeded(PowerRequestExecutionRequired);
} else {
ReleaseWakelockIfNeeded(PowerRequestExecutionRequired);
}
} else {
if (requestLock) {
RequestWakelockIfNeeded(PowerRequestDisplayRequired);
} else {
ReleaseWakelockIfNeeded(PowerRequestDisplayRequired);
}
}
return NS_OK;
}
// Handle would only exist when we request wakelock successfully.
HANDLE mDisplayHandle = nullptr;
HANDLE mNonDisplayHandle = nullptr;
};
NS_IMPL_ISUPPORTS(WinWakeLockListener, nsIDOMMozWakeLockListener)
StaticRefPtr<nsIDOMMozWakeLockListener> 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;
}
}
class SingleNativeEventPump final : public nsIThreadObserver {
public:
NS_DECL_THREADSAFE_ISUPPORTS
NS_DECL_NSITHREADOBSERVER
SingleNativeEventPump() {
MOZ_ASSERT(!XRE_UseNativeEventProcessing(),
"Should only be used when not properly processing events.");
}
private:
~SingleNativeEventPump() {}
};
NS_IMPL_ISUPPORTS(SingleNativeEventPump, nsIThreadObserver)
NS_IMETHODIMP
SingleNativeEventPump::OnDispatchedEvent() { return NS_OK; }
NS_IMETHODIMP
SingleNativeEventPump::OnProcessNextEvent(nsIThreadInternal* aThread,
bool aMayWait) {
MSG msg;
bool gotMessage = WinUtils::PeekMessage(&msg, nullptr, 0, 0, PM_REMOVE);
if (gotMessage) {
::TranslateMessage(&msg);
::DispatchMessageW(&msg);
}
return NS_OK;
}
NS_IMETHODIMP
SingleNativeEventPump::AfterProcessNextEvent(nsIThreadInternal* aThread,
bool aMayWait) {
return NS_OK;
}
// RegisterWindowMessage values
// Native event callback message
const wchar_t* kAppShellGeckoEventId = L"nsAppShell:EventID";
UINT sAppShellGeckoMsgId = 0x10001; // initialize to invalid message ID
// Taskbar button creation message
const wchar_t* kTaskbarButtonEventId = L"TaskbarButtonCreated";
UINT sTaskbarButtonCreatedMsg = 0x10002; // initialize to invalid message ID
/* static */
UINT nsAppShell::GetTaskbarButtonCreatedMessage() {
return sTaskbarButtonCreatedMsg;
}
namespace mozilla {
namespace crashreporter {
void LSPAnnotate();
} // namespace crashreporter
} // namespace mozilla
using mozilla::crashreporter::LSPAnnotate;
//-------------------------------------------------------------------------
// Note that since we're on x86-ish processors here, ReleaseAcquire is the
// semantics that normal loads and stores would use anyway.
static Atomic<size_t, ReleaseAcquire> sOutstandingNativeEventCallbacks;
/*static*/ LRESULT CALLBACK nsAppShell::EventWindowProc(HWND hwnd, UINT uMsg,
WPARAM wParam,
LPARAM lParam) {
NativeEventLogger eventLogger("AppShell", hwnd, uMsg, wParam, lParam);
if (uMsg == sAppShellGeckoMsgId) {
// The app shell might have been destroyed between this message being
// posted and being executed, so be extra careful.
if (!sOutstandingNativeEventCallbacks) {
return TRUE;
}
nsAppShell* as = reinterpret_cast<nsAppShell*>(lParam);
as->NativeEventCallback();
--sOutstandingNativeEventCallbacks;
return TRUE;
}
LRESULT ret = DefWindowProc(hwnd, uMsg, wParam, lParam);
eventLogger.SetResult(ret, false);
return ret;
}
nsAppShell::~nsAppShell() {
hal::Shutdown();
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);
}
// Cancel any outstanding native event callbacks.
sOutstandingNativeEventCallbacks = 0;
}
NS_IMETHODIMP
nsAppShell::Observe(nsISupports* aSubject, const char* aTopic,
const char16_t* aData) {
if (XRE_IsParentProcess()) {
nsCOMPtr<nsIObserverService> obsServ(
mozilla::services::GetObserverService());
if (!strcmp(aTopic, "sessionstore-restoring-on-startup")) {
nsWindow::SetIsRestoringSession(true);
// Now that we've handled the observer notification, we can remove it
obsServ->RemoveObserver(this, "sessionstore-restoring-on-startup");
return NS_OK;
}
if (!strcmp(aTopic, "sessionstore-windows-restored")) {
nsWindow::SetIsRestoringSession(false);
// Now that we've handled the observer notification, we can remove it
obsServ->RemoveObserver(this, "sessionstore-windows-restored");
return NS_OK;
}
}
return nsBaseAppShell::Observe(aSubject, aTopic, aData);
}
namespace {
// Struct containing information about the user atom table. (See
// DiagnoseUserAtomTable(), below.)
struct AtomTableInformation {
// Number of atoms in use. (Exactly 0x4000 == 16384, if all are.)
UINT in_use = 0;
// Number of atoms confirmed not in use.
UINT free = 0;
// Number of atoms which gave errors when checked.
UINT errors = 0;
// Last atom which gave an unexpected error...
UINT lastErrorAtom = ~0u;
// ... and the error it gave.
WinErrorState lastErrorState;
};
// Return a summary of the state of the atom table.
MOZ_NEVER_INLINE static AtomTableInformation DiagnoseUserAtomTable() {
// Restore error state on exit, for the sake of automated minidump analyses.
auto const _restoreErrState =
mozilla::MakeScopeExit([oldErrState = WinErrorState::Get()]() {
WinErrorState::Apply(oldErrState);
});
AtomTableInformation retval;
// Expected error-state on failure-return when the atom is assigned, but not
// enough space was provided for the full string.
constexpr WinErrorState kBufferTooSmall = {
.error = ERROR_INSUFFICIENT_BUFFER,
.ntStatus = ((NTSTATUS)0xC0000023), // == STATUS_BUFFER_TOO_SMALL
};
// Expected error-state on failure-return when the atom is not assigned.
constexpr WinErrorState kInvalidAtom = {
.error = ERROR_INVALID_HANDLE,
.ntStatus = ((NTSTATUS)STATUS_INVALID_HANDLE),
};
// Iterate over only the dynamic portion of the atom table.
for (UINT atom = 0xC000; atom <= 0xFFFF; ++atom) {
// The actual atom values are PII. Don't acquire them in their entirety, and
// don't keep more information about them than is needed.
WCHAR buf[2] = {};
// USE OF UNDOCUMENTED BEHAVIOR: The user atom table is shared by message
// names, window-class names, and clipboard-format names. Only the last has
// a documented getter-mechanism.
BOOL const ok = ::GetClipboardFormatNameW(atom, buf, 1);
WinErrorState const errState = WinErrorState::Get();
if (ok || errState == kBufferTooSmall) {
++retval.in_use;
} else if (errState == kInvalidAtom) {
++retval.free;
} else {
// Unexpected error-state.
++retval.errors;
retval.lastErrorAtom = atom;
retval.lastErrorState = errState;
}
}
return retval;
}
#if defined(MOZ_DIAGNOSTIC_ASSERT_ENABLED) && defined(_M_X64)
static constexpr int kMaxStepsUser32 = 0x1800;
static constexpr int kMaxErrorStatesUser32 = 0x200;
using User32SingleStepData =
ModuleSingleStepData<kMaxStepsUser32, kMaxErrorStatesUser32>;
template <typename CallbackToRun, typename PostCollectionCallback>
WindowsDiagnosticsError CollectUser32SingleStepData(
CallbackToRun aCallbackToRun,
PostCollectionCallback aPostCollectionCallback) {
return CollectModuleSingleStepData<kMaxStepsUser32, kMaxErrorStatesUser32>(
L"user32.dll", std::move(aCallbackToRun),
std::move(aPostCollectionCallback));
}
#endif // MOZ_DIAGNOSTIC_ASSERT_ENABLED && _M_X64
} // namespace
// Collect data for bug 1571516. We don't automatically send up `GetLastError`
// or `GetLastNtStatus` data for beta/release builds, so extract the relevant
// error values and store them on the stack, where they can be viewed in
// minidumps -- in fact, do so after each individual API call. This takes the
// form of various local variables whose initial character is an underscore,
// most of which are also marked [[maybe_unused]].
//
// We tag this function `[[clang::optnone]]` to prevent the compiler from
// eliding those values as _actually_ unused, as well as to generally simplify
// the haruspex's task once the minidumps are in. (As this function should be
// called at most once per process, the minor performance hit is not a concern.)
//
[[clang::optnone]] MOZ_NEVER_INLINE nsresult nsAppShell::InitHiddenWindow() {
// note the incoming error-state; this may be relevant to errors we get later
auto _initialErr [[maybe_unused]] = WinErrorState::Get();
// reset the error-state, to avoid ambiguity below
WinErrorState::Clear();
// Diagnostic variable. Only collected in the event of a failure in one of the
// functions that attempts to register an atom.
AtomTableInformation _atomTableInfo [[maybe_unused]];
// Attempt to register the window message. On failure, retain the initial
// value of `sAppShellGeckoMsgId`.
auto const _msgId = ::RegisterWindowMessageW(kAppShellGeckoEventId);
if (_msgId) {
sAppShellGeckoMsgId = _msgId;
}
auto const _sAppShellGeckoMsgId [[maybe_unused]] = sAppShellGeckoMsgId;
auto const _rwmErr [[maybe_unused]] = WinErrorState::Get();
if (!_msgId) _atomTableInfo = DiagnoseUserAtomTable();
NS_ASSERTION(sAppShellGeckoMsgId,
"Could not register hidden window event message!");
mLastNativeEventScheduled = TimeStamp::NowLoRes();
WNDCLASSW wc;
HINSTANCE const module = GetModuleHandle(nullptr);
constexpr const wchar_t* kWindowClass = L"nsAppShell:EventWindowClass";
// (Undocumented behavior note: on success, this will specifically be the
// window-class atom. We don't rely on this.)
BOOL const _gciwRet = ::GetClassInfoW(module, kWindowClass, &wc);
auto const _gciwErr [[maybe_unused]] = WinErrorState::Get();
WinErrorState::Clear();
WinErrorState _rcErr [[maybe_unused]];
if (!_gciwRet) {
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;
ATOM _windowClassAtom = ::RegisterClassW(&wc);
_rcErr = WinErrorState::Get();
if (!_windowClassAtom) _atomTableInfo = DiagnoseUserAtomTable();
#if defined(MOZ_DIAGNOSTIC_ASSERT_ENABLED) && defined(_M_X64)
if (!_windowClassAtom) {
// Retry with single-step data collection
WindowsDiagnosticsError rv = CollectUser32SingleStepData(
[&wc, &_windowClassAtom]() {
_windowClassAtom = ::RegisterClassW(&wc);
},
[&_windowClassAtom](const User32SingleStepData& aData) {
// Crashing here gives access to the single step data on stack
MOZ_DIAGNOSTIC_ASSERT(
_windowClassAtom,
"RegisterClassW for EventWindowClass failed twice");
});
auto const _cssdErr [[maybe_unused]] = WinErrorState::Get();
MOZ_DIAGNOSTIC_ASSERT(
rv == WindowsDiagnosticsError::None,
"Failed to collect single step data for RegisterClassW");
// If we reach this point then somehow the single-stepped call succeeded
// and we can proceed
}
#endif // MOZ_DIAGNOSTIC_ASSERT_ENABLED && _M_X64
MOZ_DIAGNOSTIC_ASSERT(_windowClassAtom,
"RegisterClassW for EventWindowClass failed");
WinErrorState::Clear();
}
mEventWnd = CreateWindowW(kWindowClass, L"nsAppShell:EventWindow", 0, 0, 0,
10, 10, HWND_MESSAGE, nullptr, module, nullptr);
auto const _cwErr [[maybe_unused]] = WinErrorState::Get();
#if defined(MOZ_DIAGNOSTIC_ASSERT_ENABLED) && defined(_M_X64)
if (!mEventWnd) {
// Retry with single-step data collection
HWND eventWnd{};
WindowsDiagnosticsError rv = CollectUser32SingleStepData(
[module, &eventWnd]() {
eventWnd =
CreateWindowW(kWindowClass, L"nsAppShell:EventWindow", 0, 0, 0,
10, 10, HWND_MESSAGE, nullptr, module, nullptr);
},
[&eventWnd](const User32SingleStepData& aData) {
// Crashing here gives access to the single step data on stack
MOZ_DIAGNOSTIC_ASSERT(eventWnd,
"CreateWindowW for EventWindow failed twice");
});
auto const _cssdErr [[maybe_unused]] = WinErrorState::Get();
MOZ_DIAGNOSTIC_ASSERT(
rv == WindowsDiagnosticsError::None,
"Failed to collect single step data for CreateWindowW");
// If we reach this point then somehow the single-stepped call succeeded and
// we can proceed
mEventWnd = eventWnd;
}
#endif // MOZ_DIAGNOSTIC_ASSERT_ENABLED && _M_X64
MOZ_DIAGNOSTIC_ASSERT(mEventWnd, "CreateWindowW for EventWindow failed");
NS_ENSURE_STATE(mEventWnd);
return NS_OK;
}
nsresult nsAppShell::Init() {
LSPAnnotate();
hal::Init();
if (XRE_IsParentProcess()) {
sTaskbarButtonCreatedMsg = ::RegisterWindowMessageW(kTaskbarButtonEventId);
NS_ASSERTION(sTaskbarButtonCreatedMsg,
"Could not register taskbar button creation message");
}
// The hidden message window is used for interrupting the processing of native
// events, so that we can process gecko events. Therefore, we only need it if
// we are processing native events. Disabling this is required for win32k
// syscall lockdown.
if (XRE_UseNativeEventProcessing()) {
if (nsresult rv = this->InitHiddenWindow(); NS_FAILED(rv)) {
return rv;
}
} else if (XRE_IsContentProcess() && !IsWin32kLockedDown()) {
// We're not generally processing native events, but still using GDI and we
// still have some internal windows, e.g. from calling CoInitializeEx.
// So we use a class that will do a single event pump where previously we
// might have processed multiple events to make sure any occasional messages
// to these windows are processed. This also allows any internal Windows
// messages to be processed to ensure the GDI data remains fresh.
nsCOMPtr<nsIThreadInternal> threadInt =
do_QueryInterface(NS_GetCurrentThread());
if (threadInt) {
threadInt->SetObserver(new SingleNativeEventPump());
}
}
if (XRE_IsParentProcess()) {
ScreenManager& screenManager = ScreenManager::GetSingleton();
if (gfxPlatform::IsHeadless()) {
screenManager.SetHelper(mozilla::MakeUnique<HeadlessScreenHelper>());
} else {
screenManager.SetHelper(mozilla::MakeUnique<ScreenHelperWin>());
ScreenHelperWin::RefreshScreens();
}
nsCOMPtr<nsIObserverService> obsServ(
mozilla::services::GetObserverService());
obsServ->AddObserver(this, "sessionstore-restoring-on-startup", false);
obsServ->AddObserver(this, "sessionstore-windows-restored", false);
}
if (!WinUtils::GetTimezoneName(mTimezoneName)) {
NS_WARNING("Unable to get system timezone name, timezone may be invalid\n");
}
return nsBaseAppShell::Init();
}
NS_IMETHODIMP
nsAppShell::Run(void) {
bool wantAudio = true;
if (XRE_IsParentProcess()) {
#ifdef MOZ_BACKGROUNDTASKS
if (BackgroundTasks::IsBackgroundTaskMode()) {
wantAudio = false;
}
#endif
if (MOZ_LIKELY(wantAudio)) {
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. Whole firefox
// only needs one wakelock instance, so we would only create one listener in
// chrome process to prevent requesting unnecessary wakelock.
AddScreenWakeLockListener();
}
nsresult rv = nsBaseAppShell::Run();
if (XRE_IsParentProcess()) {
RemoveScreenWakeLockListener();
if (MOZ_LIKELY(wantAudio)) {
mozilla::widget::StopAudioSession();
}
}
return rv;
}
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();
mNativeCallbackPending = false;
} else {
mNativeCallbackPending = true;
}
}
void nsAppShell::ScheduleNativeEventCallback() {
MOZ_ASSERT(mEventWnd,
"We should have created mEventWnd in Init, if this is called.");
// Post a message to the hidden message window
++sOutstandingNativeEventCallbacks;
{
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;
// 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");
}
if (!gotMessage) {
gotMessage = WinUtils::PeekMessage(&msg, nullptr, 0, 0, PM_REMOVE);
}
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::BackgroundHangMonitor().NotifyActivity();
if (msg.message >= WM_KEYFIRST && msg.message <= WM_KEYLAST &&
IMEHandler::ProcessRawKeyMessage(msg)) {
continue; // the message is consumed.
}
#if defined(_X86_)
// Store Printer dialog messages for reposting on x86, because on x86
// Windows 7 they are not processed by a window procedure, but are
// explicitly waited for in the winspool.drv code that will be further
// up the stack (winspool!WaitForCompletionMessage). These are
// undocumented Windows Message identifiers found in winspool.drv.
if (msg.message == 0x5b7a || msg.message == 0x5b7f ||
msg.message == 0x5b80 || msg.message == 0x5b81) {
mMsgsToRepost.push_back(msg);
continue;
}
#endif
// Windows documentation suggets that WM_SETTINGSCHANGE is the message
// to watch for timezone changes, but experimentation showed that it
// doesn't fire on changing the timezone, but that WM_TIMECHANGE does,
// even if there's no immediate effect on the clock (e.g., changing
// from Pacific Daylight at UTC-7 to Arizona at UTC-7).
if (msg.message == WM_TIMECHANGE) {
// The message may not give us sufficient information to determine
// if the timezone changed, so keep track of it ourselves.
wchar_t systemTimezone[128];
bool getSystemTimeSucceeded =
WinUtils::GetTimezoneName(systemTimezone);
if (getSystemTimeSucceeded && wcscmp(systemTimezone, mTimezoneName)) {
nsBaseAppShell::OnSystemTimezoneChange();
wcscpy_s(mTimezoneName, 128, systemTimezone);
}
}
::TranslateMessage(&msg);
::DispatchMessageW(&msg);
}
} else if (mayWait) {
// Block and wait for any posted application message
mozilla::BackgroundHangMonitor().NotifyWait();
{
AUTO_PROFILER_LABEL("nsAppShell::ProcessNextNativeEvent::Wait", IDLE);
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;
}
nsresult nsAppShell::AfterProcessNextEvent(nsIThreadInternal* /* unused */,
bool /* unused */) {
if (!mMsgsToRepost.empty()) {
for (MSG msg : mMsgsToRepost) {
::PostMessageW(msg.hwnd, msg.message, msg.wParam, msg.lParam);
}
mMsgsToRepost.clear();
}
return NS_OK;
}