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Diffstat (limited to 'ipc/glue/WindowsMessageLoop.cpp')
| -rw-r--r-- | ipc/glue/WindowsMessageLoop.cpp | 1205 |
1 files changed, 1205 insertions, 0 deletions
diff --git a/ipc/glue/WindowsMessageLoop.cpp b/ipc/glue/WindowsMessageLoop.cpp new file mode 100644 index 0000000000..51bb7c8531 --- /dev/null +++ b/ipc/glue/WindowsMessageLoop.cpp @@ -0,0 +1,1205 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* 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/DebugOnly.h" + +#include "WindowsMessageLoop.h" +#include "Neutering.h" +#include "MessageChannel.h" + +#include "nsServiceManagerUtils.h" +#include "nsString.h" +#include "WinUtils.h" + +#include "mozilla/ArrayUtils.h" +#include "mozilla/dom/JSExecutionManager.h" +#include "mozilla/gfx/Logging.h" +#include "mozilla/ipc/ProtocolUtils.h" +#include "mozilla/mscom/Utils.h" +#include "mozilla/PaintTracker.h" +#include "mozilla/UniquePtr.h" +#include "mozilla/WindowsProcessMitigations.h" + +using namespace mozilla; +using namespace mozilla::ipc; +using namespace mozilla::ipc::windows; + +/** + * The Windows-only code below exists to solve a general problem with deadlocks + * that we experience when sending synchronous IPC messages to processes that + * contain native windows (i.e. HWNDs). Windows (the OS) sends synchronous + * messages between parent and child HWNDs in multiple circumstances (e.g. + * WM_PARENTNOTIFY, WM_NCACTIVATE, etc.), even when those HWNDs are controlled + * by different threads or different processes. Thus we can very easily end up + * in a deadlock by a call stack like the following: + * + * Process A: + * - CreateWindow(...) creates a "parent" HWND. + * - SendCreateChildWidget(HWND) is a sync IPC message that sends the "parent" + * HWND over to Process B. Process A blocks until a response is received + * from Process B. + * + * Process B: + * - RecvCreateWidget(HWND) gets the "parent" HWND from Process A. + * - CreateWindow(..., HWND) creates a "child" HWND with the parent from + * process A. + * - Windows (the OS) generates a WM_PARENTNOTIFY message that is sent + * synchronously to Process A. Process B blocks until a response is + * received from Process A. Process A, however, is blocked and cannot + * process the message. Both processes are deadlocked. + * + * The example above has a few different workarounds (e.g. setting the + * WS_EX_NOPARENTNOTIFY style on the child window) but the general problem is + * persists. Once two HWNDs are parented we must not block their owning + * threads when manipulating either HWND. + * + * Windows requires any application that hosts native HWNDs to always process + * messages or risk deadlock. Given our architecture the only way to meet + * Windows' requirement and allow for synchronous IPC messages is to pump a + * miniature message loop during a sync IPC call. We avoid processing any + * queued messages during the loop (with one exception, see below), but + * "nonqueued" messages (see + * http://msdn.microsoft.com/en-us/library/ms644927(VS.85).aspx under the + * section "Nonqueued messages") cannot be avoided. Those messages are trapped + * in a special window procedure where we can either ignore the message or + * process it in some fashion. + * + * Queued and "non-queued" messages will be processed during Interrupt calls if + * modal UI related api calls block an Interrupt in-call in the child. To + * prevent windows from freezing, and to allow concurrent processing of critical + * events (such as painting), we spin a native event dispatch loop while + * these in-calls are blocked. + */ + +#if defined(ACCESSIBILITY) +// pulled from accessibility's win utils +extern const wchar_t* kPropNameTabContent; +#endif + +// widget related message id constants we need to defer, see nsAppShell. +extern UINT sAppShellGeckoMsgId; + +namespace { + +const wchar_t kOldWndProcProp[] = L"MozillaIPCOldWndProc"; +const wchar_t k3rdPartyWindowProp[] = L"Mozilla3rdPartyWindow"; + +// This isn't defined before Windows XP. +enum { WM_XP_THEMECHANGED = 0x031A }; + +nsTArray<HWND>* gNeuteredWindows = nullptr; + +typedef nsTArray<UniquePtr<DeferredMessage>> DeferredMessageArray; +DeferredMessageArray* gDeferredMessages = nullptr; + +HHOOK gDeferredGetMsgHook = nullptr; +HHOOK gDeferredCallWndProcHook = nullptr; + +DWORD gUIThreadId = 0; +HWND gCOMWindow = 0; +// Once initialized, gWinEventHook is never unhooked. We save the handle so +// that we can check whether or not the hook is initialized. +HWINEVENTHOOK gWinEventHook = nullptr; +const wchar_t kCOMWindowClassName[] = L"OleMainThreadWndClass"; + +// WM_GETOBJECT id pulled from uia headers +#define MOZOBJID_UIAROOT -25 + +HWND FindCOMWindow() { + MOZ_ASSERT(gUIThreadId); + + HWND last = 0; + while ( + (last = FindWindowExW(HWND_MESSAGE, last, kCOMWindowClassName, NULL))) { + if (GetWindowThreadProcessId(last, NULL) == gUIThreadId) { + return last; + } + } + + return (HWND)0; +} + +void CALLBACK WinEventHook(HWINEVENTHOOK aWinEventHook, DWORD aEvent, + HWND aHwnd, LONG aIdObject, LONG aIdChild, + DWORD aEventThread, DWORD aMsEventTime) { + MOZ_ASSERT(aWinEventHook == gWinEventHook); + MOZ_ASSERT(gUIThreadId == aEventThread); + switch (aEvent) { + case EVENT_OBJECT_CREATE: { + if (aIdObject != OBJID_WINDOW || aIdChild != CHILDID_SELF) { + // Not an event we're interested in + return; + } + wchar_t classBuf[256] = {0}; + int result = ::GetClassNameW(aHwnd, classBuf, MOZ_ARRAY_LENGTH(classBuf)); + if (result != (MOZ_ARRAY_LENGTH(kCOMWindowClassName) - 1) || + wcsncmp(kCOMWindowClassName, classBuf, result)) { + // Not a class we're interested in + return; + } + MOZ_ASSERT(FindCOMWindow() == aHwnd); + gCOMWindow = aHwnd; + break; + } + case EVENT_OBJECT_DESTROY: { + if (aHwnd == gCOMWindow && aIdObject == OBJID_WINDOW) { + MOZ_ASSERT(aIdChild == CHILDID_SELF); + gCOMWindow = 0; + } + break; + } + default: { + return; + } + } +} + +LRESULT CALLBACK DeferredMessageHook(int nCode, WPARAM wParam, LPARAM lParam) { + // XXX This function is called for *both* the WH_CALLWNDPROC hook and the + // WH_GETMESSAGE hook, but they have different parameters. We don't + // use any of them except nCode which has the same meaning. + + // Only run deferred messages if all of these conditions are met: + // 1. The |nCode| indicates that this hook should do something. + // 2. We have deferred messages to run. + // 3. We're not being called from the PeekMessage within the WaitFor*Notify + // function (indicated with MessageChannel::IsPumpingMessages). We really + // only want to run after returning to the main event loop. + if (nCode >= 0 && gDeferredMessages && !MessageChannel::IsPumpingMessages()) { + NS_ASSERTION(gDeferredGetMsgHook && gDeferredCallWndProcHook, + "These hooks must be set if we're being called!"); + NS_ASSERTION(gDeferredMessages->Length(), "No deferred messages?!"); + + // Unset hooks first, in case we reenter below. + UnhookWindowsHookEx(gDeferredGetMsgHook); + UnhookWindowsHookEx(gDeferredCallWndProcHook); + gDeferredGetMsgHook = 0; + gDeferredCallWndProcHook = 0; + + // Unset the global and make sure we delete it when we're done here. + auto messages = WrapUnique(gDeferredMessages); + gDeferredMessages = nullptr; + + // Run all the deferred messages in order. + uint32_t count = messages->Length(); + for (uint32_t index = 0; index < count; index++) { + messages->ElementAt(index)->Run(); + } + } + + // Always call the next hook. + return CallNextHookEx(nullptr, nCode, wParam, lParam); +} + +void ScheduleDeferredMessageRun() { + if (gDeferredMessages && !(gDeferredGetMsgHook && gDeferredCallWndProcHook)) { + NS_ASSERTION(gDeferredMessages->Length(), "No deferred messages?!"); + + gDeferredGetMsgHook = ::SetWindowsHookEx(WH_GETMESSAGE, DeferredMessageHook, + nullptr, gUIThreadId); + gDeferredCallWndProcHook = ::SetWindowsHookEx( + WH_CALLWNDPROC, DeferredMessageHook, nullptr, gUIThreadId); + NS_ASSERTION(gDeferredGetMsgHook && gDeferredCallWndProcHook, + "Failed to set hooks!"); + } +} + +static void DumpNeuteredMessage(HWND hwnd, UINT uMsg) { +#ifdef DEBUG + nsAutoCString log("Received \"nonqueued\" "); + // classify messages + if (uMsg < WM_USER) { + const char* msgText = mozilla::widget::WinUtils::WinEventToEventName(uMsg); + if (msgText) { + log.AppendPrintf("ui message \"%s\"", msgText); + } else { + log.AppendPrintf("ui message (0x%X)", uMsg); + } + } else if (uMsg >= WM_USER && uMsg < WM_APP) { + log.AppendPrintf("WM_USER message (0x%X)", uMsg); + } else if (uMsg >= WM_APP && uMsg < 0xC000) { + log.AppendPrintf("WM_APP message (0x%X)", uMsg); + } else if (uMsg >= 0xC000 && uMsg < 0x10000) { + log.AppendPrintf("registered windows message (0x%X)", uMsg); + } else { + log.AppendPrintf("system message (0x%X)", uMsg); + } + + log.AppendLiteral(" during a synchronous IPC message for window "); + log.AppendPrintf("0x%p", hwnd); + + wchar_t className[256] = {0}; + if (GetClassNameW(hwnd, className, sizeof(className) - 1) > 0) { + log.AppendLiteral(" (\""); + log.Append(NS_ConvertUTF16toUTF8((char16_t*)className)); + log.AppendLiteral("\")"); + } + + log.AppendLiteral( + ", sending it to DefWindowProc instead of the normal " + "window procedure."); + NS_ERROR(log.get()); +#endif +} + +LRESULT +ProcessOrDeferMessage(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam) { + UniquePtr<DeferredMessage> deferred; + + // Most messages ask for 0 to be returned if the message is processed. + LRESULT res = 0; + + switch (uMsg) { + // Messages that can be deferred as-is. These must not contain pointers in + // their wParam or lParam arguments! + case WM_ACTIVATE: + case WM_ACTIVATEAPP: + case WM_CANCELMODE: + case WM_CAPTURECHANGED: + case WM_CHILDACTIVATE: + case WM_DESTROY: + case WM_ENABLE: + case WM_IME_NOTIFY: + case WM_IME_SETCONTEXT: + case WM_KILLFOCUS: + case WM_MOUSEWHEEL: + case WM_NCDESTROY: + case WM_PARENTNOTIFY: + case WM_SETFOCUS: + case WM_SYSCOMMAND: + case WM_DISPLAYCHANGE: + case WM_SHOWWINDOW: // Intentional fall-through. + case WM_XP_THEMECHANGED: { + deferred = MakeUnique<DeferredSendMessage>(hwnd, uMsg, wParam, lParam); + break; + } + + case WM_DEVICECHANGE: + case WM_POWERBROADCAST: + case WM_NCACTIVATE: // Intentional fall-through. + case WM_SETCURSOR: { + // Friggin unconventional return value... + res = TRUE; + deferred = MakeUnique<DeferredSendMessage>(hwnd, uMsg, wParam, lParam); + break; + } + + case WM_MOUSEACTIVATE: { + res = MA_NOACTIVATE; + deferred = MakeUnique<DeferredSendMessage>(hwnd, uMsg, wParam, lParam); + break; + } + + // These messages need to use the RedrawWindow function to generate the + // right kind of message. We can't simply fake them as the MSDN docs say + // explicitly that paint messages should not be sent by an application. + case WM_ERASEBKGND: { + UINT flags = RDW_INVALIDATE | RDW_ERASE | RDW_NOINTERNALPAINT | + RDW_NOFRAME | RDW_NOCHILDREN | RDW_ERASENOW; + deferred = MakeUnique<DeferredRedrawMessage>(hwnd, flags); + break; + } + + // This message will generate a WM_PAINT message if there are invalid + // areas. + case WM_PAINT: { + deferred = MakeUnique<DeferredUpdateMessage>(hwnd); + break; + } + + // This message holds a string in its lParam that we must copy. + case WM_SETTINGCHANGE: { + deferred = + MakeUnique<DeferredSettingChangeMessage>(hwnd, uMsg, wParam, lParam); + break; + } + + // These messages are faked via a call to SetWindowPos. + case WM_WINDOWPOSCHANGED: { + deferred = MakeUnique<DeferredWindowPosMessage>(hwnd, lParam); + break; + } + case WM_NCCALCSIZE: { + deferred = + MakeUnique<DeferredWindowPosMessage>(hwnd, lParam, true, wParam); + break; + } + + case WM_COPYDATA: { + deferred = + MakeUnique<DeferredCopyDataMessage>(hwnd, uMsg, wParam, lParam); + res = TRUE; + break; + } + + case WM_STYLECHANGED: { + deferred = MakeUnique<DeferredStyleChangeMessage>(hwnd, wParam, lParam); + break; + } + + case WM_SETICON: { + deferred = MakeUnique<DeferredSetIconMessage>(hwnd, uMsg, wParam, lParam); + break; + } + + // Messages that are safe to pass to DefWindowProc go here. + case WM_ENTERIDLE: + case WM_GETICON: + case WM_NCPAINT: // (never trap nc paint events) + case WM_GETMINMAXINFO: + case WM_GETTEXT: + case WM_NCHITTEST: + case WM_STYLECHANGING: // Intentional fall-through. + case WM_WINDOWPOSCHANGING: + case WM_GETTEXTLENGTH: { + return DefWindowProc(hwnd, uMsg, wParam, lParam); + } + + // Just return, prevents DefWindowProc from messaging the window + // syncronously with other events, which may be deferred. Prevents + // random shutdown of aero composition on the window. + case WM_SYNCPAINT: + return 0; + + // This message causes QuickTime to make re-entrant calls. + // Simply discarding it doesn't seem to hurt anything. + case WM_APP - 1: + return 0; + + // We only support a query for our IAccessible or UIA pointers. + // This should be safe, and needs to be sync. +#if defined(ACCESSIBILITY) + case WM_GETOBJECT: { + if (!::GetPropW(hwnd, k3rdPartyWindowProp)) { + LONG objId = static_cast<LONG>(lParam); + if (objId == OBJID_CLIENT || objId == MOZOBJID_UIAROOT) { + WNDPROC oldWndProc = (WNDPROC)GetProp(hwnd, kOldWndProcProp); + if (oldWndProc) { + return CallWindowProcW(oldWndProc, hwnd, uMsg, wParam, lParam); + } + } + } + return DefWindowProc(hwnd, uMsg, wParam, lParam); + } +#endif // ACCESSIBILITY + + default: { + // Unknown messages only are logged in debug builds and sent to + // DefWindowProc. + if (uMsg && uMsg == sAppShellGeckoMsgId) { + // Widget's registered native event callback + deferred = MakeUnique<DeferredSendMessage>(hwnd, uMsg, wParam, lParam); + } + } + } + + // No deferred message was created and we land here, this is an + // unhandled message. + if (!deferred) { + DumpNeuteredMessage(hwnd, uMsg); + return DefWindowProc(hwnd, uMsg, wParam, lParam); + } + + // Create the deferred message array if it doesn't exist already. + if (!gDeferredMessages) { + gDeferredMessages = new DeferredMessageArray(20); + } + + // Save for later. The array takes ownership of |deferred|. + gDeferredMessages->AppendElement(std::move(deferred)); + return res; +} + +} // namespace + +LRESULT CALLBACK NeuteredWindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, + LPARAM lParam) { + WNDPROC oldWndProc = (WNDPROC)GetProp(hwnd, kOldWndProcProp); + if (!oldWndProc) { + // We should really never ever get here. + NS_ERROR("No old wndproc!"); + return DefWindowProc(hwnd, uMsg, wParam, lParam); + } + + // See if we care about this message. We may either ignore it, send it to + // DefWindowProc, or defer it for later. + return ProcessOrDeferMessage(hwnd, uMsg, wParam, lParam); +} + +namespace { + +static bool WindowIsDeferredWindow(HWND hWnd) { + if (!IsWindow(hWnd)) { + NS_WARNING("Window has died!"); + return false; + } + + char16_t buffer[256] = {0}; + int length = GetClassNameW(hWnd, (wchar_t*)buffer, sizeof(buffer) - 1); + if (length <= 0) { + NS_WARNING("Failed to get class name!"); + return false; + } + +#if defined(ACCESSIBILITY) + // Tab content creates a window that responds to accessible WM_GETOBJECT + // calls. This window can safely be ignored. + if (::GetPropW(hWnd, kPropNameTabContent)) { + return false; + } +#endif + + // Common mozilla windows we must defer messages to. + nsDependentString className(buffer, length); + if (StringBeginsWith(className, u"Mozilla"_ns) || + StringBeginsWith(className, u"Gecko"_ns) || + className.EqualsLiteral("nsToolkitClass") || + className.EqualsLiteral("nsAppShell:EventWindowClass")) { + return true; + } + + // Plugin windows that can trigger ipc calls in child: + // 'ShockwaveFlashFullScreen' - flash fullscreen window + if (className.EqualsLiteral("ShockwaveFlashFullScreen")) { + SetPropW(hWnd, k3rdPartyWindowProp, (HANDLE)1); + return true; + } + + return false; +} + +bool NeuterWindowProcedure(HWND hWnd) { + if (!WindowIsDeferredWindow(hWnd)) { + // Some other kind of window, skip. + return false; + } + + NS_ASSERTION(!GetProp(hWnd, kOldWndProcProp), "This should always be null!"); + + // It's possible to get nullptr out of SetWindowLongPtr, and the only way to + // know if that's a valid old value is to use GetLastError. Clear the error + // here so we can tell. + SetLastError(ERROR_SUCCESS); + + LONG_PTR currentWndProc = + SetWindowLongPtr(hWnd, GWLP_WNDPROC, (LONG_PTR)NeuteredWindowProc); + if (!currentWndProc) { + if (ERROR_SUCCESS == GetLastError()) { + // No error, so we set something and must therefore reset it. + SetWindowLongPtr(hWnd, GWLP_WNDPROC, currentWndProc); + } + return false; + } + + NS_ASSERTION(currentWndProc != (LONG_PTR)NeuteredWindowProc, + "This shouldn't be possible!"); + + if (!SetProp(hWnd, kOldWndProcProp, (HANDLE)currentWndProc)) { + // Cleanup + NS_WARNING("SetProp failed!"); + SetWindowLongPtr(hWnd, GWLP_WNDPROC, currentWndProc); + RemovePropW(hWnd, kOldWndProcProp); + RemovePropW(hWnd, k3rdPartyWindowProp); + return false; + } + + return true; +} + +void RestoreWindowProcedure(HWND hWnd) { + NS_ASSERTION(WindowIsDeferredWindow(hWnd), + "Not a deferred window, this shouldn't be in our list!"); + LONG_PTR oldWndProc = (LONG_PTR)GetProp(hWnd, kOldWndProcProp); + if (oldWndProc) { + NS_ASSERTION(oldWndProc != (LONG_PTR)NeuteredWindowProc, + "This shouldn't be possible!"); + + DebugOnly<LONG_PTR> currentWndProc = + SetWindowLongPtr(hWnd, GWLP_WNDPROC, oldWndProc); + NS_ASSERTION(currentWndProc == (LONG_PTR)NeuteredWindowProc, + "This should never be switched out from under us!"); + } + RemovePropW(hWnd, kOldWndProcProp); + RemovePropW(hWnd, k3rdPartyWindowProp); +} + +LRESULT CALLBACK CallWindowProcedureHook(int nCode, WPARAM wParam, + LPARAM lParam) { + if (nCode >= 0) { + NS_ASSERTION(gNeuteredWindows, "This should never be null!"); + + HWND hWnd = reinterpret_cast<CWPSTRUCT*>(lParam)->hwnd; + + if (!gNeuteredWindows->Contains(hWnd) && + !SuppressedNeuteringRegion::IsNeuteringSuppressed() && + NeuterWindowProcedure(hWnd)) { + // XXX(Bug 1631371) Check if this should use a fallible operation as it + // pretended earlier. + gNeuteredWindows->AppendElement(hWnd); + } + } + return CallNextHookEx(nullptr, nCode, wParam, lParam); +} + +inline void AssertWindowIsNotNeutered(HWND hWnd) { +#ifdef DEBUG + // Make sure our neutered window hook isn't still in place. + LONG_PTR wndproc = GetWindowLongPtr(hWnd, GWLP_WNDPROC); + NS_ASSERTION(wndproc != (LONG_PTR)NeuteredWindowProc, "Window is neutered!"); +#endif +} + +void UnhookNeuteredWindows() { + if (!gNeuteredWindows) return; + uint32_t count = gNeuteredWindows->Length(); + for (uint32_t index = 0; index < count; index++) { + RestoreWindowProcedure(gNeuteredWindows->ElementAt(index)); + } + gNeuteredWindows->Clear(); +} + +// This timeout stuff assumes a sane value of mTimeoutMs (less than the overflow +// value for GetTickCount(), which is something like 50 days). It uses the +// cheapest (and least accurate) method supported by Windows 2000. + +struct TimeoutData { + DWORD startTicks; + DWORD targetTicks; +}; + +void InitTimeoutData(TimeoutData* aData, int32_t aTimeoutMs) { + aData->startTicks = GetTickCount(); + if (!aData->startTicks) { + // How unlikely is this! + aData->startTicks++; + } + aData->targetTicks = aData->startTicks + aTimeoutMs; +} + +bool TimeoutHasExpired(const TimeoutData& aData) { + if (!aData.startTicks) { + return false; + } + + DWORD now = GetTickCount(); + + if (aData.targetTicks < aData.startTicks) { + // Overflow + return now < aData.startTicks && now >= aData.targetTicks; + } + return now >= aData.targetTicks; +} + +} // namespace + +namespace mozilla { +namespace ipc { +namespace windows { + +void InitUIThread() { + if (!XRE_UseNativeEventProcessing()) { + return; + } + // If we aren't setup before a call to NotifyWorkerThread, we'll hang + // on startup. + if (!gUIThreadId) { + gUIThreadId = GetCurrentThreadId(); + } + + MOZ_ASSERT(gUIThreadId); + MOZ_ASSERT(gUIThreadId == GetCurrentThreadId(), + "Called InitUIThread multiple times on different threads!"); + + if (!gWinEventHook && !mscom::IsCurrentThreadMTA()) { + gWinEventHook = SetWinEventHook(EVENT_OBJECT_CREATE, EVENT_OBJECT_DESTROY, + NULL, &WinEventHook, GetCurrentProcessId(), + gUIThreadId, WINEVENT_OUTOFCONTEXT); + MOZ_ASSERT(gWinEventHook); + + // We need to execute this after setting the hook in case the OLE window + // already existed. + gCOMWindow = FindCOMWindow(); + } +} + +} // namespace windows +} // namespace ipc +} // namespace mozilla + +// See SpinInternalEventLoop below +MessageChannel::SyncStackFrame::SyncStackFrame(MessageChannel* channel) + : mSpinNestedEvents(false), + mListenerNotified(false), + mChannel(channel), + mPrev(mChannel->mTopFrame), + mStaticPrev(sStaticTopFrame) { + // Only track stack frames when Windows message deferral behavior + // is request for the channel. + if (!(mChannel->GetChannelFlags() & REQUIRE_DEFERRED_MESSAGE_PROTECTION)) { + return; + } + + mChannel->mTopFrame = this; + sStaticTopFrame = this; + + if (!mStaticPrev) { + NS_ASSERTION(!gNeuteredWindows, "Should only set this once!"); + gNeuteredWindows = new AutoTArray<HWND, 20>(); + NS_ASSERTION(gNeuteredWindows, "Out of memory!"); + } +} + +MessageChannel::SyncStackFrame::~SyncStackFrame() { + if (!(mChannel->GetChannelFlags() & REQUIRE_DEFERRED_MESSAGE_PROTECTION)) { + return; + } + + NS_ASSERTION(this == mChannel->mTopFrame, + "Mismatched interrupt stack frames"); + NS_ASSERTION(this == sStaticTopFrame, + "Mismatched static Interrupt stack frames"); + + mChannel->mTopFrame = mPrev; + sStaticTopFrame = mStaticPrev; + + if (!mStaticPrev) { + NS_ASSERTION(gNeuteredWindows, "Bad pointer!"); + delete gNeuteredWindows; + gNeuteredWindows = nullptr; + } +} + +MessageChannel::SyncStackFrame* MessageChannel::sStaticTopFrame; + +// nsAppShell's notification that gecko events are being processed. +// If we are here and there is an Interrupt Incall active, we are spinning +// a nested gecko event loop. In which case the remote process needs +// to know about it. +void /* static */ +MessageChannel::NotifyGeckoEventDispatch() { + // sStaticTopFrame is only valid for Interrupt channels + if (!sStaticTopFrame || sStaticTopFrame->mListenerNotified) return; + + sStaticTopFrame->mListenerNotified = true; + MessageChannel* channel = + static_cast<MessageChannel*>(sStaticTopFrame->mChannel); + channel->Listener()->ProcessRemoteNativeEventsInInterruptCall(); +} + +// invoked by the module that receives the spin event loop +// message. +void MessageChannel::ProcessNativeEventsInInterruptCall() { + NS_ASSERTION(GetCurrentThreadId() == gUIThreadId, + "Shouldn't be on a non-main thread in here!"); + if (!mTopFrame) { + NS_ERROR("Spin logic error: no Interrupt frame"); + return; + } + + mTopFrame->mSpinNestedEvents = true; +} + +// Spin loop is called in place of WaitFor*Notify when modal ui is being shown +// in a child. There are some intricacies in using it however. Spin loop is +// enabled for a particular Interrupt frame by the client calling +// MessageChannel::ProcessNativeEventsInInterrupt(). +// This call can be nested for multiple Interrupt frames in a single plugin or +// multiple unrelated plugins. +void MessageChannel::SpinInternalEventLoop() { + if (mozilla::PaintTracker::IsPainting()) { + MOZ_CRASH("Don't spin an event loop while painting."); + } + + NS_ASSERTION(mTopFrame && mTopFrame->mSpinNestedEvents, + "Spinning incorrectly"); + + // Nested windows event loop we trigger when the child enters into modal + // event loops. + + // Note, when we return, we always reset the notify worker event. So there's + // no need to reset it on return here. + + do { + MSG msg = {0}; + + // Don't get wrapped up in here if the child connection dies. + { + MonitorAutoLock lock(*mMonitor); + if (!Connected()) { + return; + } + } + + // Retrieve window or thread messages + if (PeekMessageW(&msg, nullptr, 0, 0, PM_REMOVE)) { + // The child UI should have been destroyed before the app is closed, in + // which case, we should never get this here. + if (msg.message == WM_QUIT) { + NS_ERROR("WM_QUIT received in SpinInternalEventLoop!"); + } else { + TranslateMessage(&msg); + ::DispatchMessageW(&msg); + return; + } + } + + // Note, give dispatching windows events priority over checking if + // mEvent is signaled, otherwise heavy ipc traffic can cause jittery + // playback of video. We'll exit out on each disaptch above, so ipc + // won't get starved. + + // Wait for UI events or a signal from the io thread. + DWORD result = + MsgWaitForMultipleObjects(1, &mEvent, FALSE, INFINITE, QS_ALLINPUT); + if (result == WAIT_OBJECT_0) { + // Our NotifyWorkerThread event was signaled + return; + } + } while (true); +} + +static HHOOK gWindowHook; + +static inline void StartNeutering() { + if (!gUIThreadId) { + mozilla::ipc::windows::InitUIThread(); + } + MOZ_ASSERT(gUIThreadId); + MOZ_ASSERT(!gWindowHook); + NS_ASSERTION(!MessageChannel::IsPumpingMessages(), + "Shouldn't be pumping already!"); + MessageChannel::SetIsPumpingMessages(true); + gWindowHook = ::SetWindowsHookEx(WH_CALLWNDPROC, CallWindowProcedureHook, + nullptr, gUIThreadId); + NS_ASSERTION(gWindowHook, "Failed to set hook!"); +} + +static void StopNeutering() { + MOZ_ASSERT(MessageChannel::IsPumpingMessages()); + ::UnhookWindowsHookEx(gWindowHook); + gWindowHook = NULL; + ::UnhookNeuteredWindows(); + // Before returning we need to set a hook to run any deferred messages that + // we received during the IPC call. The hook will unset itself as soon as + // someone else calls GetMessage, PeekMessage, or runs code that generates + // a "nonqueued" message. + ::ScheduleDeferredMessageRun(); + MessageChannel::SetIsPumpingMessages(false); +} + +NeuteredWindowRegion::NeuteredWindowRegion(bool aDoNeuter) + : mNeuteredByThis(!gWindowHook && aDoNeuter && + XRE_UseNativeEventProcessing()) { + if (mNeuteredByThis) { + StartNeutering(); + } +} + +NeuteredWindowRegion::~NeuteredWindowRegion() { + if (gWindowHook && mNeuteredByThis) { + StopNeutering(); + } +} + +void NeuteredWindowRegion::PumpOnce() { + if (!gWindowHook) { + // This should be a no-op if nothing has been neutered. + return; + } + + MSG msg = {0}; + // Pump any COM messages so that we don't hang due to STA marshaling. + if (gCOMWindow && ::PeekMessageW(&msg, gCOMWindow, 0, 0, PM_REMOVE)) { + ::TranslateMessage(&msg); + ::DispatchMessageW(&msg); + } + // Expunge any nonqueued messages on the current thread. + ::PeekMessageW(&msg, nullptr, 0, 0, PM_NOREMOVE); +} + +DeneuteredWindowRegion::DeneuteredWindowRegion() + : mReneuter(gWindowHook != NULL) { + if (mReneuter) { + StopNeutering(); + } +} + +DeneuteredWindowRegion::~DeneuteredWindowRegion() { + if (mReneuter) { + StartNeutering(); + } +} + +SuppressedNeuteringRegion::SuppressedNeuteringRegion() + : mReenable(::gUIThreadId == ::GetCurrentThreadId() && ::gWindowHook) { + if (mReenable) { + MOZ_ASSERT(!sSuppressNeutering); + sSuppressNeutering = true; + } +} + +SuppressedNeuteringRegion::~SuppressedNeuteringRegion() { + if (mReenable) { + MOZ_ASSERT(sSuppressNeutering); + sSuppressNeutering = false; + } +} + +bool SuppressedNeuteringRegion::sSuppressNeutering = false; + +bool MessageChannel::WaitForSyncNotify() { + mMonitor->AssertCurrentThreadOwns(); + + if (!gUIThreadId) { + mozilla::ipc::windows::InitUIThread(); + } + + // Use a blocking wait if this channel does not require + // Windows message deferral behavior. + if (!(mFlags & REQUIRE_DEFERRED_MESSAGE_PROTECTION)) { + TimeDuration timeout = (kNoTimeout == mTimeoutMs) + ? TimeDuration::Forever() + : TimeDuration::FromMilliseconds(mTimeoutMs); + + MOZ_ASSERT(!mIsSyncWaitingOnNonMainThread); + mIsSyncWaitingOnNonMainThread = true; + + CVStatus status = mMonitor->Wait(timeout); + + MOZ_ASSERT(mIsSyncWaitingOnNonMainThread); + mIsSyncWaitingOnNonMainThread = false; + + // If the timeout didn't expire, we know we received an event. The + // converse is not true. + return WaitResponse(status == CVStatus::Timeout); + } + + NS_ASSERTION( + mFlags & REQUIRE_DEFERRED_MESSAGE_PROTECTION, + "Shouldn't be here for channels that don't use message deferral!"); + NS_ASSERTION(mTopFrame, "No top frame!"); + + MonitorAutoUnlock unlock(*mMonitor); + + bool timedout = false; + + UINT_PTR timerId = 0; + TimeoutData timeoutData = {0}; + + if (mTimeoutMs != kNoTimeout) { + InitTimeoutData(&timeoutData, mTimeoutMs); + + // We only do this to ensure that we won't get stuck in + // MsgWaitForMultipleObjects below. + timerId = SetTimer(nullptr, 0, mTimeoutMs, nullptr); + NS_ASSERTION(timerId, "SetTimer failed!"); + } + + NeuteredWindowRegion neuteredRgn(true); + + { + while (1) { + MSG msg = {0}; + // Don't get wrapped up in here if the child connection dies. + { + MonitorAutoLock lock(*mMonitor); + if (!Connected()) { + break; + } + } + + // Wait until we have a message in the queue. MSDN docs are a bit unclear + // but it seems that windows from two different threads (and it should be + // noted that a thread in another process counts as a "different thread") + // will implicitly have their message queues attached if they are parented + // to one another. This wait call, then, will return for a message + // delivered to *either* thread. + DWORD result = + MsgWaitForMultipleObjects(1, &mEvent, FALSE, INFINITE, QS_ALLINPUT); + if (result == WAIT_OBJECT_0) { + // Our NotifyWorkerThread event was signaled + BOOL success = ResetEvent(mEvent); + if (!success) { + gfxDevCrash(mozilla::gfx::LogReason::MessageChannelInvalidHandle) + << "WindowsMessageChannel::WaitForSyncNotify failed to reset " + "event. GetLastError: " + << GetLastError(); + } + break; + } else if (result != (WAIT_OBJECT_0 + 1)) { + NS_ERROR("Wait failed!"); + break; + } + + if (TimeoutHasExpired(timeoutData)) { + // A timeout was specified and we've passed it. Break out. + timedout = true; + break; + } + + // The only way to know on which thread the message was delivered is to + // use some logic on the return values of GetQueueStatus and PeekMessage. + // PeekMessage will return false if there are no "queued" messages, but it + // will run all "nonqueued" messages before returning. So if PeekMessage + // returns false and there are no "nonqueued" messages that were run then + // we know that the message we woke for was intended for a window on + // another thread. + bool haveSentMessagesPending = + (HIWORD(GetQueueStatus(QS_SENDMESSAGE)) & QS_SENDMESSAGE) != 0; + + // Either of the PeekMessage calls below will actually process all + // "nonqueued" messages that are pending before returning. If we have + // "nonqueued" messages pending then we should have switched out all the + // window procedures above. In that case this PeekMessage call won't + // actually cause any mozilla code (or plugin code) to run. + + // We have to manually pump all COM messages *after* looking at the queue + // queue status but before yielding our thread below. + if (gCOMWindow) { + if (PeekMessageW(&msg, gCOMWindow, 0, 0, PM_REMOVE)) { + TranslateMessage(&msg); + ::DispatchMessageW(&msg); + } + } + + // If the following PeekMessage call fails to return a message for us (and + // returns false) and we didn't run any "nonqueued" messages then we must + // have woken up for a message designated for a window in another thread. + // If we loop immediately then we could enter a tight loop, so we'll give + // up our time slice here to let the child process its message. + if (!PeekMessageW(&msg, nullptr, 0, 0, PM_NOREMOVE) && + !haveSentMessagesPending) { + // Message was for child, we should wait a bit. + SwitchToThread(); + } + } + } + + if (timerId) { + KillTimer(nullptr, timerId); + timerId = 0; + } + + return WaitResponse(timedout); +} + +void MessageChannel::NotifyWorkerThread() { + mMonitor->AssertCurrentThreadOwns(); + + if (mIsSyncWaitingOnNonMainThread) { + mMonitor->Notify(); + return; + } + + MOZ_RELEASE_ASSERT(mEvent, "No signal event to set, this is really bad!"); + if (!SetEvent(mEvent)) { + NS_WARNING("Failed to set NotifyWorkerThread event!"); + gfxDevCrash(mozilla::gfx::LogReason::MessageChannelInvalidHandle) + << "WindowsMessageChannel failed to SetEvent. GetLastError: " + << GetLastError(); + } +} + +void DeferredSendMessage::Run() { + AssertWindowIsNotNeutered(hWnd); + if (!IsWindow(hWnd)) { + NS_ERROR("Invalid window!"); + return; + } + + WNDPROC wndproc = + reinterpret_cast<WNDPROC>(GetWindowLongPtr(hWnd, GWLP_WNDPROC)); + if (!wndproc) { + NS_ERROR("Invalid window procedure!"); + return; + } + + CallWindowProc(wndproc, hWnd, message, wParam, lParam); +} + +void DeferredRedrawMessage::Run() { + AssertWindowIsNotNeutered(hWnd); + if (!IsWindow(hWnd)) { + NS_ERROR("Invalid window!"); + return; + } + +#ifdef DEBUG + BOOL ret = +#endif + RedrawWindow(hWnd, nullptr, nullptr, flags); + NS_ASSERTION(ret, "RedrawWindow failed!"); +} + +DeferredUpdateMessage::DeferredUpdateMessage(HWND aHWnd) { + mWnd = aHWnd; + if (!GetUpdateRect(mWnd, &mUpdateRect, FALSE)) { + memset(&mUpdateRect, 0, sizeof(RECT)); + return; + } + ValidateRect(mWnd, &mUpdateRect); +} + +void DeferredUpdateMessage::Run() { + AssertWindowIsNotNeutered(mWnd); + if (!IsWindow(mWnd)) { + NS_ERROR("Invalid window!"); + return; + } + + InvalidateRect(mWnd, &mUpdateRect, FALSE); +#ifdef DEBUG + BOOL ret = +#endif + UpdateWindow(mWnd); + NS_ASSERTION(ret, "UpdateWindow failed!"); +} + +DeferredSettingChangeMessage::DeferredSettingChangeMessage(HWND aHWnd, + UINT aMessage, + WPARAM aWParam, + LPARAM aLParam) + : DeferredSendMessage(aHWnd, aMessage, aWParam, aLParam) { + NS_ASSERTION(aMessage == WM_SETTINGCHANGE, "Wrong message type!"); + if (aLParam) { + lParamString = _wcsdup(reinterpret_cast<const wchar_t*>(aLParam)); + lParam = reinterpret_cast<LPARAM>(lParamString); + } else { + lParamString = nullptr; + lParam = 0; + } +} + +DeferredSettingChangeMessage::~DeferredSettingChangeMessage() { + free(lParamString); +} + +DeferredWindowPosMessage::DeferredWindowPosMessage(HWND aHWnd, LPARAM aLParam, + bool aForCalcSize, + WPARAM aWParam) { + if (aForCalcSize) { + if (aWParam) { + NCCALCSIZE_PARAMS* arg = reinterpret_cast<NCCALCSIZE_PARAMS*>(aLParam); + memcpy(&windowPos, arg->lppos, sizeof(windowPos)); + + NS_ASSERTION(aHWnd == windowPos.hwnd, "Mismatched hwnds!"); + } else { + RECT* arg = reinterpret_cast<RECT*>(aLParam); + windowPos.hwnd = aHWnd; + windowPos.hwndInsertAfter = nullptr; + windowPos.x = arg->left; + windowPos.y = arg->top; + windowPos.cx = arg->right - arg->left; + windowPos.cy = arg->bottom - arg->top; + + NS_ASSERTION(arg->right >= arg->left && arg->bottom >= arg->top, + "Negative width or height!"); + } + windowPos.flags = SWP_FRAMECHANGED | SWP_NOACTIVATE | SWP_NOOWNERZORDER | + SWP_NOZORDER | SWP_DEFERERASE | SWP_NOSENDCHANGING; + } else { + // Not for WM_NCCALCSIZE + WINDOWPOS* arg = reinterpret_cast<WINDOWPOS*>(aLParam); + memcpy(&windowPos, arg, sizeof(windowPos)); + + NS_ASSERTION(aHWnd == windowPos.hwnd, "Mismatched hwnds!"); + + // Windows sends in some private flags sometimes that we can't simply copy. + // Filter here. + UINT mask = SWP_ASYNCWINDOWPOS | SWP_DEFERERASE | SWP_DRAWFRAME | + SWP_FRAMECHANGED | SWP_HIDEWINDOW | SWP_NOACTIVATE | + SWP_NOCOPYBITS | SWP_NOMOVE | SWP_NOOWNERZORDER | SWP_NOREDRAW | + SWP_NOREPOSITION | SWP_NOSENDCHANGING | SWP_NOSIZE | + SWP_NOZORDER | SWP_SHOWWINDOW; + windowPos.flags &= mask; + } +} + +void DeferredWindowPosMessage::Run() { + AssertWindowIsNotNeutered(windowPos.hwnd); + if (!IsWindow(windowPos.hwnd)) { + NS_ERROR("Invalid window!"); + return; + } + + if (!IsWindow(windowPos.hwndInsertAfter)) { + NS_WARNING("ZOrder change cannot be honored"); + windowPos.hwndInsertAfter = 0; + windowPos.flags |= SWP_NOZORDER; + } + +#ifdef DEBUG + BOOL ret = +#endif + SetWindowPos(windowPos.hwnd, windowPos.hwndInsertAfter, windowPos.x, + windowPos.y, windowPos.cx, windowPos.cy, windowPos.flags); + NS_ASSERTION(ret, "SetWindowPos failed!"); +} + +DeferredCopyDataMessage::DeferredCopyDataMessage(HWND aHWnd, UINT aMessage, + WPARAM aWParam, LPARAM aLParam) + : DeferredSendMessage(aHWnd, aMessage, aWParam, aLParam) { + NS_ASSERTION(IsWindow(reinterpret_cast<HWND>(aWParam)), "Bad window!"); + + COPYDATASTRUCT* source = reinterpret_cast<COPYDATASTRUCT*>(aLParam); + NS_ASSERTION(source, "Should never be null!"); + + copyData.dwData = source->dwData; + copyData.cbData = source->cbData; + + if (source->cbData) { + copyData.lpData = malloc(source->cbData); + if (copyData.lpData) { + memcpy(copyData.lpData, source->lpData, source->cbData); + } else { + NS_ERROR("Out of memory?!"); + copyData.cbData = 0; + } + } else { + copyData.lpData = nullptr; + } + + lParam = reinterpret_cast<LPARAM>(©Data); +} + +DeferredCopyDataMessage::~DeferredCopyDataMessage() { free(copyData.lpData); } + +DeferredStyleChangeMessage::DeferredStyleChangeMessage(HWND aHWnd, + WPARAM aWParam, + LPARAM aLParam) + : hWnd(aHWnd) { + index = static_cast<int>(aWParam); + style = reinterpret_cast<STYLESTRUCT*>(aLParam)->styleNew; +} + +void DeferredStyleChangeMessage::Run() { SetWindowLongPtr(hWnd, index, style); } + +DeferredSetIconMessage::DeferredSetIconMessage(HWND aHWnd, UINT aMessage, + WPARAM aWParam, LPARAM aLParam) + : DeferredSendMessage(aHWnd, aMessage, aWParam, aLParam) { + NS_ASSERTION(aMessage == WM_SETICON, "Wrong message type!"); +} + +void DeferredSetIconMessage::Run() { + AssertWindowIsNotNeutered(hWnd); + if (!IsWindow(hWnd)) { + NS_ERROR("Invalid window!"); + return; + } + + WNDPROC wndproc = + reinterpret_cast<WNDPROC>(GetWindowLongPtr(hWnd, GWLP_WNDPROC)); + if (!wndproc) { + NS_ERROR("Invalid window procedure!"); + return; + } + + HICON hOld = reinterpret_cast<HICON>( + CallWindowProc(wndproc, hWnd, message, wParam, lParam)); + if (hOld) { + DestroyIcon(hOld); + } +} |