gecko-dev/ipc/glue/WindowsMessageLoop.cpp
Jim Mathies 02e1abfaad Bug 538918 - follow up patch: IsMessagePending should use PeekMessage, not the stacks for detection.
--HG--
extra : transplant_source : %3D%E4_%CE7m%FE%8F%B0S%DC%9F%FAF%D7%40%5D%83%C1/
2010-02-09 22:47:44 -06:00

1038 lines
34 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: sw=2 ts=2 et :
*/
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Mozilla Plugin App.
*
* The Initial Developer of the Original Code is
* Ben Turner <bent.mozilla@gmail.com>
* Portions created by the Initial Developer are Copyright (C) 2009
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Jim Mathies <jmathies@mozilla.com>
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#include "WindowsMessageLoop.h"
#include "RPCChannel.h"
#include "nsAutoPtr.h"
#include "nsServiceManagerUtils.h"
#include "nsStringGlue.h"
#include "nsIXULAppInfo.h"
#include "mozilla/Mutex.h"
using mozilla::ipc::SyncChannel;
using mozilla::ipc::RPCChannel;
using mozilla::MutexAutoUnlock;
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 RPC calls if
* modal UI related api calls block an RPC 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.
*/
namespace {
UINT gEventLoopMessage =
RegisterWindowMessage(L"SyncChannel Windows Message Loop Message");
UINT gOOPPSpinNativeLoopEvent =
RegisterWindowMessage(L"SyncChannel Spin Inner Loop Message");
UINT gOOPPStopNativeLoopEvent =
RegisterWindowMessage(L"SyncChannel Stop Inner Loop Message");
const wchar_t kOldWndProcProp[] = L"MozillaIPCOldWndProc";
// This isn't defined before Windows XP.
enum { WM_XP_THEMECHANGED = 0x031A };
PRUnichar gAppMessageWindowName[256] = { 0 };
PRInt32 gAppMessageWindowNameLength = 0;
nsTArray<HWND>* gNeuteredWindows = nsnull;
typedef nsTArray<nsAutoPtr<DeferredMessage> > DeferredMessageArray;
DeferredMessageArray* gDeferredMessages = nsnull;
HHOOK gDeferredGetMsgHook = NULL;
HHOOK gDeferredCallWndProcHook = NULL;
DWORD gUIThreadId = 0;
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 WaitForNotify
// function (indicated with SyncChannel::IsPumpingMessages). We really
// only want to run after returning to the main event loop.
if (nCode >= 0 && gDeferredMessages && !SyncChannel::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.
nsAutoPtr<DeferredMessageArray> messages(gDeferredMessages);
gDeferredMessages = nsnull;
// Run all the deferred messages in order.
PRUint32 count = messages->Length();
for (PRUint32 index = 0; index < count; index++) {
messages->ElementAt(index)->Run();
}
}
// Always call the next hook.
return CallNextHookEx(NULL, nCode, wParam, lParam);
}
void
ScheduleDeferredMessageRun()
{
if (gDeferredMessages &&
!(gDeferredGetMsgHook && gDeferredCallWndProcHook)) {
NS_ASSERTION(gDeferredMessages->Length(), "No deferred messages?!");
gDeferredGetMsgHook = ::SetWindowsHookEx(WH_GETMESSAGE, DeferredMessageHook,
NULL, gUIThreadId);
gDeferredCallWndProcHook = ::SetWindowsHookEx(WH_CALLWNDPROC,
DeferredMessageHook, NULL,
gUIThreadId);
NS_ASSERTION(gDeferredGetMsgHook && gDeferredCallWndProcHook,
"Failed to set hooks!");
}
}
LRESULT
ProcessOrDeferMessage(HWND hwnd,
UINT uMsg,
WPARAM wParam,
LPARAM lParam)
{
DeferredMessage* deferred = nsnull;
// 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_SHOWWINDOW: // Intentional fall-through.
case WM_XP_THEMECHANGED: {
deferred = new DeferredSendMessage(hwnd, uMsg, wParam, lParam);
break;
}
case WM_DEVICECHANGE:
case WM_NCACTIVATE: // Intentional fall-through.
case WM_SETCURSOR: {
// Friggin unconventional return value...
res = TRUE;
deferred = new DeferredSendMessage(hwnd, uMsg, wParam, lParam);
break;
}
case WM_MOUSEACTIVATE: {
res = MA_NOACTIVATE;
deferred = new 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 = new DeferredRedrawMessage(hwnd, flags);
break;
}
case WM_NCPAINT: {
UINT flags = RDW_INVALIDATE | RDW_FRAME | RDW_NOINTERNALPAINT |
RDW_NOERASE | RDW_NOCHILDREN | RDW_ERASENOW;
deferred = new DeferredRedrawMessage(hwnd, flags);
break;
}
// This message will generate a WM_PAINT message if there are invalid
// areas.
case WM_PAINT: {
deferred = new DeferredUpdateMessage(hwnd);
break;
}
// This message holds a string in its lParam that we must copy.
case WM_SETTINGCHANGE: {
deferred = new DeferredSettingChangeMessage(hwnd, uMsg, wParam, lParam);
break;
}
// These messages are faked via a call to SetWindowPos.
case WM_WINDOWPOSCHANGED: {
deferred = new DeferredWindowPosMessage(hwnd, lParam);
break;
}
case WM_NCCALCSIZE: {
deferred = new DeferredWindowPosMessage(hwnd, lParam, true, wParam);
break;
}
case WM_COPYDATA: {
deferred = new DeferredCopyDataMessage(hwnd, uMsg, wParam, lParam);
res = TRUE;
break;
}
// Messages that are safe to pass to DefWindowProc go here.
case WM_ENTERIDLE:
case WM_GETICON:
case WM_GETMINMAXINFO:
case WM_GETTEXT:
case WM_NCHITTEST:
case WM_SETICON:
case WM_STYLECHANGING:
case WM_STYLECHANGED:
case WM_SYNCPAINT: // Intentional fall-through.
case WM_WINDOWPOSCHANGING: {
return DefWindowProc(hwnd, uMsg, wParam, lParam);
}
// Unknown messages only.
default: {
#ifdef DEBUG
nsCAutoString log("Received \"nonqueued\" message ");
log.AppendInt(uMsg);
log.AppendLiteral(" during a synchronous IPC message for window ");
log.AppendInt((PRInt64)hwnd);
wchar_t className[256] = { 0 };
if (GetClassNameW(hwnd, className, sizeof(className) - 1) > 0) {
log.AppendLiteral(" (\"");
log.Append(NS_ConvertUTF16toUTF8((PRUnichar*)className));
log.AppendLiteral("\")");
}
log.AppendLiteral(", sending it to DefWindowProc instead of the normal "
"window procedure.");
NS_ERROR(log.get());
#endif
return DefWindowProc(hwnd, uMsg, wParam, lParam);
}
}
NS_ASSERTION(deferred, "Must have a message here!");
// Create the deferred message array if it doesn't exist already.
if (!gDeferredMessages) {
gDeferredMessages = new nsTArray<nsAutoPtr<DeferredMessage> >(20);
NS_ASSERTION(gDeferredMessages, "Out of memory!");
}
// Save for later. The array takes ownership of |deferred|.
gDeferredMessages->AppendElement(deferred);
return res;
}
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);
}
static bool
WindowIsMozillaWindow(HWND hWnd)
{
if (!IsWindow(hWnd)) {
NS_WARNING("Window has died!");
return false;
}
PRUnichar 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;
}
nsDependentString className(buffer, length);
if (StringBeginsWith(className, NS_LITERAL_STRING("Mozilla")) ||
StringBeginsWith(className, NS_LITERAL_STRING("Gecko")) ||
className.EqualsLiteral("nsToolkitClass") ||
className.EqualsLiteral("nsAppShell:EventWindowClass")) {
return true;
}
// nsNativeAppSupport makes a window like "FirefoxMessageWindow" based on the
// toolkit app's name. It's pretty expensive to calculate this so we only try
// once.
if (gAppMessageWindowNameLength == 0) {
nsCOMPtr<nsIXULAppInfo> appInfo =
do_GetService("@mozilla.org/xre/app-info;1");
if (appInfo) {
nsCAutoString appName;
if (NS_SUCCEEDED(appInfo->GetName(appName))) {
appName.Append("MessageWindow");
nsDependentString windowName(gAppMessageWindowName);
CopyUTF8toUTF16(appName, windowName);
gAppMessageWindowNameLength = windowName.Length();
}
}
// Don't try again if that failed.
if (gAppMessageWindowNameLength == 0) {
gAppMessageWindowNameLength = -1;
}
}
if (gAppMessageWindowNameLength != -1 &&
className.Equals(nsDependentString(gAppMessageWindowName,
gAppMessageWindowNameLength))) {
return true;
}
return false;
}
bool
NeuterWindowProcedure(HWND hWnd)
{
if (!WindowIsMozillaWindow(hWnd)) {
// Some other kind of window, skip.
return false;
}
NS_ASSERTION(!GetProp(hWnd, kOldWndProcProp), "This should always be null!");
// It's possible to get NULL 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);
RemoveProp(hWnd, kOldWndProcProp);
return false;
}
return true;
}
void
RestoreWindowProcedure(HWND hWnd)
{
NS_ASSERTION(WindowIsMozillaWindow(hWnd),
"Not a mozilla window, this shouldn't be in our list!");
LONG_PTR oldWndProc = (LONG_PTR)RemoveProp(hWnd, kOldWndProcProp);
if (oldWndProc) {
NS_ASSERTION(oldWndProc != (LONG_PTR)NeuteredWindowProc,
"This shouldn't be possible!");
LONG_PTR currentWndProc =
SetWindowLongPtr(hWnd, GWLP_WNDPROC, oldWndProc);
NS_ASSERTION(currentWndProc == (LONG_PTR)NeuteredWindowProc,
"This should never be switched out from under us!");
}
}
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) && NeuterWindowProcedure(hWnd)) {
if (!gNeuteredWindows->AppendElement(hWnd)) {
NS_ERROR("Out of memory!");
RestoreWindowProcedure(hWnd);
}
}
}
return CallNextHookEx(NULL, 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;
PRUint32 count = gNeuteredWindows->Length();
for (PRUint32 index = 0; index < count; index++) {
RestoreWindowProcedure(gNeuteredWindows->ElementAt(index));
}
gNeuteredWindows->Clear();
}
void
Init()
{
// If we aren't setup before a call to NotifyWorkerThread, we'll hang
// on startup.
if (!gUIThreadId) {
gUIThreadId = GetCurrentThreadId();
}
NS_ASSERTION(gUIThreadId, "ThreadId should not be 0!");
NS_ASSERTION(gUIThreadId == GetCurrentThreadId(),
"Running on different threads!");
if (!gNeuteredWindows) {
gNeuteredWindows = new nsAutoTArray<HWND, 20>();
}
NS_ASSERTION(gNeuteredWindows, "Out of memory!");
}
} // anonymous namespace
bool
RPCChannel::SpinInternalEventLoop()
{
// Nested windows event loop that's triggered when the child enters into modal
// event procedures.
do {
MSG msg = { 0 };
// Don't get wrapped up in here if the child connection dies.
{
MutexAutoLock lock(mMutex);
if (!Connected()) {
RPCChannel::ExitModalLoop();
return false;
}
}
if (!RPCChannel::IsSpinLoopActive()) {
return false;
}
// If a modal loop in the child has exited, we want to disable the spin
// loop. However, we must continue to wait for a response from the last
// rpc call. Returning false here will cause the thread to drop down
// into deferred message processing.
if (PeekMessageW(&msg, (HWND)-1, gOOPPStopNativeLoopEvent,
gOOPPStopNativeLoopEvent, PM_REMOVE)) {
RPCChannel::ExitModalLoop();
return false;
}
// At whatever depth we currently sit, a reply to the rpc call we were
// waiting for has been received. Exit out of here and respond to it.
// Returning true here causes the WaitForNotify() to return.
if (PeekMessageW(&msg, (HWND)-1, gEventLoopMessage, gEventLoopMessage,
PM_REMOVE)) {
return true;
}
// Retrieve window or thread messages
if (PeekMessageW(&msg, NULL, 0, 0, PM_REMOVE)) {
if (msg.message == gOOPPStopNativeLoopEvent) {
RPCChannel::ExitModalLoop();
return false;
}
else if (msg.message == gOOPPSpinNativeLoopEvent) {
// Keep the spin loop counter accurate, multiple plugins can show ui.
RPCChannel::EnterModalLoop();
continue;
}
else if (msg.message == gEventLoopMessage) {
return true;
}
// 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);
}
} else {
// Block and wait for any posted application messages
WaitMessage();
}
} while (true);
}
bool
RPCChannel::IsMessagePending()
{
MSG msg = { 0 };
if (PeekMessageW(&msg, (HWND)-1, gEventLoopMessage, gEventLoopMessage,
PM_REMOVE)) {
return true;
}
return false;
}
bool
SyncChannel::WaitForNotify()
{
mMutex.AssertCurrentThreadOwns();
MutexAutoUnlock unlock(mMutex);
// Initialize global objects used in deferred messaging.
Init();
// Setup deferred processing of native events while we wait for a response.
NS_ASSERTION(!SyncChannel::IsPumpingMessages(),
"Shouldn't be pumping already!");
SyncChannel::SetIsPumpingMessages(true);
HHOOK windowHook = SetWindowsHookEx(WH_CALLWNDPROC, CallWindowProcedureHook,
NULL, gUIThreadId);
NS_ASSERTION(windowHook, "Failed to set hook!");
{
while (1) {
MSG msg = { 0 };
// Don't get wrapped up in here if the child connection dies.
{
MutexAutoLock lock(mMutex);
if (!Connected()) {
return true;
}
}
// 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(0, NULL, FALSE, INFINITE,
QS_ALLINPUT);
if (result != WAIT_OBJECT_0) {
NS_ERROR("Wait failed!");
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;
// This PeekMessage call 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 check first to see if we should break out of the loop by looking for
// the special message from the IO thread. We pull it out of the queue.
if (PeekMessageW(&msg, (HWND)-1, gEventLoopMessage, gEventLoopMessage,
PM_REMOVE)) {
break;
}
// 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, NULL, 0, 0, PM_NOREMOVE) &&
!haveSentMessagesPending) {
// Message was for child, we should wait a bit.
SwitchToThread();
}
}
}
// Unhook the neutered window procedure hook.
UnhookWindowsHookEx(windowHook);
// Unhook any neutered windows procedures so messages can be delivered
// normally.
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();
SyncChannel::SetIsPumpingMessages(false);
return true;
}
bool
RPCChannel::WaitForNotify()
{
mMutex.AssertCurrentThreadOwns();
if (!StackDepth()) {
NS_ASSERTION(!StackDepth(),
"StackDepth() is 0 in a call to RPCChannel::WaitForNotify?");
return true;
}
MutexAutoUnlock unlock(mMutex);
// Initialize global objects used in deferred messaging.
Init();
// IsSpinLoopActive indicates modal UI is being displayed in a plugin. Drop
// down into the spin loop until all modal loops end. If SpinInternalEventLoop
// returns true, the out-call response we were waiting on arrived, or we
// received an in-call request from child, so return from WaitForNotify.
// We'll step back down into the spin loop on the next WaitForNotify call.
// If the spin loop returns false, the child's modal loop has ended, so
// drop down into "normal" deferred processing until the next reply is
// received. Note, spin loop can cause reentrant race conditions, which
// is expected.
if (RPCChannel::IsSpinLoopActive()) {
if (SpinInternalEventLoop()) {
return true;
}
// Coming out of spin loop after a modal loop ends, we can't drop into
// deferred processing on the assumption that MsgWaitForMultipleObjects
// will get signaled with gEventLoopMessage - messages may have already
// been received and stored in mPending & mOutOfTurnReplies. So we check
// various stacks to figure out if we should fall through or just return.
if (IsMessagePending()) {
return true;
}
}
// Setup deferred processing of native events while we wait for a response.
NS_ASSERTION(!SyncChannel::IsPumpingMessages(),
"Shouldn't be pumping already!");
SyncChannel::SetIsPumpingMessages(true);
HHOOK windowHook = SetWindowsHookEx(WH_CALLWNDPROC, CallWindowProcedureHook,
NULL, gUIThreadId);
NS_ASSERTION(windowHook, "Failed to set hook!");
{
while (1) {
MSG msg = { 0 };
// Don't get wrapped up in here if the child connection dies.
{
MutexAutoLock lock(mMutex);
if (!Connected())
break;
}
DWORD result = MsgWaitForMultipleObjects(0, NULL, FALSE, INFINITE,
QS_ALLINPUT);
if (result != WAIT_OBJECT_0) {
NS_ERROR("Wait failed!");
break;
}
// See SyncChannel's WaitForNotify for details.
bool haveSentMessagesPending =
(HIWORD(GetQueueStatus(QS_SENDMESSAGE)) & QS_SENDMESSAGE) != 0;
// This message is received from PluginInstanceParent when the child is
// about to drop into a modal event loop. Deferred "nonqueued" events and
// backed up queued events must be delivered before this happens, and
// normal event processing must resume, otherwise UI lockups can result.
// Unhook deferred processing, purge deferred events, and drop down into
// our local event dispatch loop.
if (PeekMessageW(&msg, (HWND)-1, gOOPPSpinNativeLoopEvent,
gOOPPSpinNativeLoopEvent, PM_REMOVE)) {
// Unhook the neutered window procedure hook.
UnhookWindowsHookEx(windowHook);
windowHook = NULL;
// Used by widget to assert on incoming native events.
SyncChannel::SetIsPumpingMessages(false);
// Unhook any neutered windows procedures so messages can be delivered
// normally.
UnhookNeuteredWindows();
// Send all deferred "nonqueued" messages to the intended receiver.
// We're dropping into SpinInternalEventLoop so we should be fairly
// certain these will get deliverd soon.
ScheduleDeferredMessageRun();
// Spin the internal dispatch message loop during calls to WaitForNotify
// until the child process tells us the modal loop has closed. A return
// of true indicates gEventLoopMessage was received, exit out of
// WaitForNotify so we can deal with it in RPCChannel.
RPCChannel::EnterModalLoop();
if (SpinInternalEventLoop())
return true;
// See comments above - never assume MsgWaitForMultipleObjects will
// get signaled.
if (IsMessagePending())
return true;
// We drop out of our inner event loop after the plugin has relinquished
// control back to the shim, but the ipdl call has yet to return, so reset
// our hook in case and continue waiting on gEventLoopMessage.
windowHook = SetWindowsHookEx(WH_CALLWNDPROC, CallWindowProcedureHook,
NULL, gUIThreadId);
NS_ASSERTION(windowHook, "Failed to set proc hook on the rebound!");
SyncChannel::SetIsPumpingMessages(true);
continue;
}
if (PeekMessageW(&msg, (HWND)-1, gEventLoopMessage, gEventLoopMessage,
PM_REMOVE)) {
break;
}
if (!PeekMessageW(&msg, NULL, 0, 0, PM_NOREMOVE) &&
!haveSentMessagesPending) {
// Message was for child, we should wait a bit.
SwitchToThread();
}
}
}
// Unhook the neutered window procedure hook.
UnhookWindowsHookEx(windowHook);
// Unhook any neutered windows procedures so messages can be delivered
// normally.
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();
SyncChannel::SetIsPumpingMessages(false);
return true;
}
void
SyncChannel::NotifyWorkerThread()
{
mMutex.AssertCurrentThreadOwns();
NS_ASSERTION(gUIThreadId, "This should have been set already!");
if (!PostThreadMessage(gUIThreadId, gEventLoopMessage, 0, 0)) {
NS_WARNING("Failed to post thread message!");
}
}
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, NULL, NULL, flags);
NS_ASSERTION(ret, "RedrawWindow failed!");
}
void
DeferredUpdateMessage::Run()
{
AssertWindowIsNotNeutered(hWnd);
if (!IsWindow(hWnd)) {
NS_ERROR("Invalid window!");
return;
}
#ifdef DEBUG
BOOL ret =
#endif
UpdateWindow(hWnd);
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 {
lParam = NULL;
}
}
DeferredSettingChangeMessage::~DeferredSettingChangeMessage()
{
if (lParamString) {
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 = NULL;
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 = NULL;
}
lParam = reinterpret_cast<LPARAM>(&copyData);
}
DeferredCopyDataMessage::~DeferredCopyDataMessage()
{
free(copyData.lpData);
}