Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1000 insertions, 0 deletions

diff --git a/widget/windows/nsAppShell.cpp b/widget/windows/nsAppShell.cpp
new file mode 100644
index 0000000000..314176766d
--- /dev/null
+++ b/widget/windows/nsAppShell.cpp
@@ -0,0 +1,1000 @@
+/* -*- 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/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 storing the visible, loggable error-state of a Windows thread.
+// Approximately `std:pair(::GetLastError(), ::RtlGetLastNtStatus())`.
+//
+// Uses sentinel values rather than a proper `Maybe` type to simplify
+// minidump-analysis.
+struct WinErrorState {
+  // Last error, as provided by ::GetLastError().
+  DWORD error = ~0;
+  // Last NTSTATUS, as provided by the TIB.
+  NTSTATUS ntStatus = ~0;
+
+ private:
+  // per WINE et al.; stable since NT 3.51
+  constexpr static size_t kLastNtStatusOffset =
+      sizeof(size_t) == 8 ? 0x1250 : 0xbf4;
+
+  static void SetLastNtStatus(NTSTATUS status) {
+    auto* teb = ::NtCurrentTeb();
+    *reinterpret_cast<NTSTATUS*>(reinterpret_cast<char*>(teb) +
+                                 kLastNtStatusOffset) = status;
+  }
+
+  static NTSTATUS GetLastNtStatus() {
+    auto const* teb = ::NtCurrentTeb();
+    return *reinterpret_cast<NTSTATUS const*>(
+        reinterpret_cast<char const*>(teb) + kLastNtStatusOffset);
+  }
+
+ public:
+  // Restore (or just set) the error state of the current thread.
+  static void Apply(WinErrorState const& state) {
+    SetLastNtStatus(state.ntStatus);
+    ::SetLastError(state.error);
+  }
+
+  // Clear the error-state of the current thread.
+  static void Clear() { Apply({.error = 0, .ntStatus = 0}); }
+
+  // Get the error-state of the current thread.
+  static WinErrorState Get() {
+    return WinErrorState{
+        .error = ::GetLastError(),
+        .ntStatus = GetLastNtStatus(),
+    };
+  }
+
+  bool operator==(WinErrorState const& that) const {
+    return this->error == that.error && this->ntStatus == that.ntStatus;
+  }
+
+  bool operator!=(WinErrorState const& that) const { return !operator==(that); }
+};
+
+// 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;
+}
+
+}  // namespace
+
+#if defined(MOZ_DIAGNOSTIC_ASSERT_ENABLED) && defined(_M_X64)
+MOZ_NEVER_INLINE MOZ_NAKED void EnableTrapFlag() {
+  asm volatile(
+      "pushfq;"
+      "orw $0x100,(%rsp);"
+      "popfq;"
+      "retq;");
+}
+
+MOZ_NEVER_INLINE MOZ_NAKED void DisableTrapFlag() { asm volatile("retq;"); }
+
+#  define SSD_MAX_USER32_STEPS 0x1800
+#  define SSD_MAX_ERROR_STATES 0x200
+struct SingleStepData {
+  uint32_t mUser32StepsLog[SSD_MAX_USER32_STEPS]{};
+  WinErrorState mErrorStatesLog[SSD_MAX_ERROR_STATES];
+  uint16_t mUser32StepsAtErrorState[SSD_MAX_ERROR_STATES]{};
+};
+
+struct SingleStepStaticState {
+  SingleStepData* mData{};
+  uintptr_t mUser32Start{};
+  uintptr_t mUser32End{};
+  uint32_t mUser32Steps{};
+  uint32_t mErrorStates{};
+  WinErrorState mLastRecordedErrorState;
+
+  constexpr void Reset() { *this = SingleStepStaticState{}; }
+};
+
+static SingleStepStaticState sSingleStepStaticState{};
+
+LONG SingleStepExceptionHandler(_EXCEPTION_POINTERS* aExceptionInfo) {
+  auto& state = sSingleStepStaticState;
+  if (state.mData &&
+      aExceptionInfo->ExceptionRecord->ExceptionCode == EXCEPTION_SINGLE_STEP) {
+    auto instructionPointer = aExceptionInfo->ContextRecord->Rip;
+    if (instructionPointer == reinterpret_cast<uintptr_t>(&DisableTrapFlag)) {
+      // Stop handling any exception in this handler
+      state.mData = nullptr;
+    } else {
+      // Record data for the current step, if in user32
+      if (state.mUser32Start <= instructionPointer &&
+          instructionPointer < state.mUser32End) {
+        // We record the instruction pointer
+        if (state.mUser32Steps < SSD_MAX_USER32_STEPS) {
+          state.mData->mUser32StepsLog[state.mUser32Steps] =
+              static_cast<uint32_t>(instructionPointer - state.mUser32Start);
+        }
+
+        // We record changes in the error state
+        auto currentErrorState{WinErrorState::Get()};
+        if (currentErrorState != state.mLastRecordedErrorState) {
+          state.mLastRecordedErrorState = currentErrorState;
+
+          if (state.mErrorStates < SSD_MAX_ERROR_STATES) {
+            state.mData->mErrorStatesLog[state.mErrorStates] =
+                currentErrorState;
+            state.mData->mUser32StepsAtErrorState[state.mErrorStates] =
+                state.mUser32Steps;
+          }
+
+          ++state.mErrorStates;
+        }
+
+        ++state.mUser32Steps;
+      }
+
+      // Continue single-stepping
+      aExceptionInfo->ContextRecord->EFlags |= 0x100;
+    }
+    return EXCEPTION_CONTINUE_EXECUTION;
+  }
+  return EXCEPTION_CONTINUE_SEARCH;
+}
+
+enum CSSD_RESULT {
+  CSSD_SUCCESS = 0,
+  CSSD_ERROR_DEBUGGER_PRESENT = 1,
+  CSSD_ERROR_GET_MODULE_HANDLE = 2,
+  CSSD_ERROR_PARSING_USER32 = 3,
+  CSSD_ERROR_ADD_VECTORED_EXCEPTION_HANDLER = 4,
+};
+
+template <typename CallbackToRun, typename PostCollectionCallback>
+[[clang::optnone]] MOZ_NEVER_INLINE CSSD_RESULT
+CollectSingleStepData(CallbackToRun aCallbackToRun,
+                      PostCollectionCallback aPostCollectionCallback) {
+  if (::IsDebuggerPresent()) {
+    return CSSD_ERROR_DEBUGGER_PRESENT;
+  }
+
+  MOZ_DIAGNOSTIC_ASSERT(!sSingleStepStaticState.mData,
+                        "Single-stepping is already active");
+  HANDLE user32 = ::GetModuleHandleW(L"user32.dll");
+  if (!user32) {
+    return CSSD_ERROR_GET_MODULE_HANDLE;
+  }
+
+  nt::PEHeaders user32Headers{user32};
+  auto bounds = user32Headers.GetBounds();
+  if (bounds.isNothing()) {
+    return CSSD_ERROR_PARSING_USER32;
+  }
+
+  SingleStepData singleStepData{};
+
+  sSingleStepStaticState.Reset();
+  sSingleStepStaticState.mUser32Start =
+      reinterpret_cast<uintptr_t>(bounds.ref().begin().get());
+  sSingleStepStaticState.mUser32End =
+      reinterpret_cast<uintptr_t>(bounds.ref().end().get());
+  sSingleStepStaticState.mData = &singleStepData;
+  auto veh = ::AddVectoredExceptionHandler(TRUE, SingleStepExceptionHandler);
+  if (!veh) {
+    sSingleStepStaticState.mData = nullptr;
+    return CSSD_ERROR_ADD_VECTORED_EXCEPTION_HANDLER;
+  }
+
+  EnableTrapFlag();
+  aCallbackToRun();
+  DisableTrapFlag();
+  ::RemoveVectoredExceptionHandler(veh);
+  sSingleStepStaticState.mData = nullptr;
+
+  aPostCollectionCallback();
+
+  return CSSD_SUCCESS;
+}
+#endif  // MOZ_DIAGNOSTIC_ASSERT_ENABLED && _M_X64
+
+// 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
+      auto cssdResult = CollectSingleStepData(
+          [&wc, &_windowClassAtom]() {
+            _windowClassAtom = ::RegisterClassW(&wc);
+          },
+          [&_windowClassAtom]() {
+            // 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(
+          cssdResult == CSSD_SUCCESS,
+          "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{};
+    auto cssdResult = CollectSingleStepData(
+        [module, &eventWnd]() {
+          eventWnd =
+              CreateWindowW(kWindowClass, L"nsAppShell:EventWindow", 0, 0, 0,
+                            10, 10, HWND_MESSAGE, nullptr, module, nullptr);
+        },
+        [&eventWnd]() {
+          // 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(
+        cssdResult == CSSD_SUCCESS,
+        "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;
+}