Replace PeekMessage for TSF awareness

base/message_pump_win.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/message_pump_win.h"
 
 #include <math.h>
 
 #include "base/debug/trace_event.h"
 #include "base/message_loop.h"
 #include "base/metrics/histogram.h"
 #include "base/process_util.h"
 #include "base/win/wrapped_window_proc.h"
 
 namespace {
 
 enum MessageLoopProblems {
   MESSAGE_POST_ERROR,
   COMPLETION_POST_ERROR,
   SET_TIMER_ERROR,
   MESSAGE_LOOP_PROBLEM_MAX,
 };
 
+class SimpleMessageFilter : public base::MessagePumpForUI::MessageFilter {
+ public:
+  virtual ~SimpleMessageFilter() {}
+  virtual bool Init() OVERRIDE {
+    return true;
+  }
+  virtual BOOL DoPeekMessage(MSG* message,
+                             HWND window,
+                             UINT msg_filter_min,
+                             UINT msg_filter_max,
+                             UINT remove_msg) OVERRIDE {
+    return PeekMessage(message, window, msg_filter_min, msg_filter_max,
+                       remove_msg);
+  }
+  virtual bool ProcessMessage(const MSG& message) OVERRIDE {
+    return false;
+  }
+};
+
 }  // namespace
 
 namespace base {
 
 static const wchar_t kWndClass[] = L"Chrome_MessagePumpWindow";
 
 // Message sent to get an additional time slice for pumping (processing) another
 // task (a series of such messages creates a continuous task pump).
 static const int kMsgHaveWork = WM_USER + 1;
 
@@ skipping 54 matching lines @@
   int delay = static_cast<int>(timeout);
   if (delay < 0)
     delay = 0;
 
   return delay;
 }
 
 //-----------------------------------------------------------------------------
 // MessagePumpForUI public:
 
-MessagePumpForUI::MessagePumpForUI() : instance_(NULL) {
+MessagePumpForUI::MessagePumpForUI()
+    : instance_(NULL),
+      message_filter_(new SimpleMessageFilter) {
+  bool init = message_filter_->Init();

[darin (slow to review), 2012/09/06 03:56:55]

here, you know that Init() is a no-op.

[yoichio, 2012/09/06 09:40:37]

Done.

+  DCHECK(init);
+
   InitMessageWnd();
 }
 
 MessagePumpForUI::~MessagePumpForUI() {
   DestroyWindow(message_hwnd_);
   UnregisterClass(kWndClass, instance_);
 }
 
 void MessagePumpForUI::ScheduleWork() {
   if (InterlockedExchange(&have_work_, 1))
@@ skipping 65 matching lines @@
   if (!state_)
     return;
 
   // Create a mini-message-pump to force immediate processing of only Windows
   // WM_PAINT messages.  Don't provide an infinite loop, but do enough peeking
   // to get the job done.  Actual common max is 4 peeks, but we'll be a little
   // safe here.
   const int kMaxPeekCount = 20;
   int peek_count;
   for (peek_count = 0; peek_count < kMaxPeekCount; ++peek_count) {
-    MSG msg;
-    if (!PeekMessage(&msg, NULL, 0, 0, PM_REMOVE | PM_QS_PAINT))
+    MSG message;

[darin (slow to review), 2012/09/06 03:56:55]

nit: gratuitous variable re-naming.  elsewhere in this file it is common to use
"msg" instead of "message" for variables of type MSG.  consider cleanup changes
in a separate CL?  I'm not sure this is a good change considering that the
structure has a member named message.  It is a bit jarring to see
"message.message" in the code.  Also, if we are going to make this change, then
we should do it uniformly.  There are still some "MSG msg" left in this .cc
file.

[yoichio, 2012/09/06 09:40:37]

Done.

+    if (!PeekMessage(&message, NULL, 0, 0, PM_REMOVE | PM_QS_PAINT))
       break;
-    ProcessMessageHelper(msg);
+    ProcessMessageHelper(message);
     if (state_->should_quit)  // Handle WM_QUIT.
       break;
   }
   // Histogram what was really being used, to help to adjust kMaxPeekCount.
   DHISTOGRAM_COUNTS("Loop.PumpOutPendingPaintMessages Peeks", peek_count);
 }
 
 //-----------------------------------------------------------------------------
 // MessagePumpForUI private:
 
@@ skipping 90 matching lines @@
 
   DWORD result;
   result = MsgWaitForMultipleObjectsEx(0, NULL, delay, QS_ALLINPUT,
                                        MWMO_INPUTAVAILABLE);
 
   if (WAIT_OBJECT_0 == result) {
     // A WM_* message is available.
     // If a parent child relationship exists between windows across threads
     // then their thread inputs are implicitly attached.
     // This causes the MsgWaitForMultipleObjectsEx API to return indicating
-    // that messages are ready for processing (specifically mouse messages
-    // intended for the child window. Occurs if the child window has capture)
-    // The subsequent PeekMessages call fails to return any messages thus
+    // that messages are ready for processing (Specifically, mouse messages
+    // intended for the child window may appear if the child window has
+    // capture).
+    // The subsequent PeekMessages call may fail to return any messages thus
     // causing us to enter a tight loop at times.
     // The WaitMessage call below is a workaround to give the child window
-    // sometime to process its input messages.
+    // some time to process its input messages.
     MSG msg = {0};
     DWORD queue_status = GetQueueStatus(QS_MOUSE);
     if (HIWORD(queue_status) & QS_MOUSE &&
-       !PeekMessage(&msg, NULL, WM_MOUSEFIRST, WM_MOUSELAST, PM_NOREMOVE)) {
+        !PeekMessage(&msg, NULL, WM_MOUSEFIRST, WM_MOUSELAST, PM_NOREMOVE)) {
       WaitMessage();
     }
     return;
   }
 
   DCHECK_NE(WAIT_FAILED, result) << GetLastError();
 }
 
 void MessagePumpForUI::HandleWorkMessage() {
   // If we are being called outside of the context of Run, then don't try to do
@@ skipping 36 matching lines @@
   // If there are sent messages in the queue then PeekMessage internally
   // dispatches the message and returns false. We return true in this
   // case to ensure that the message loop peeks again instead of calling
   // MsgWaitForMultipleObjectsEx again.
   bool sent_messages_in_queue = false;
   DWORD queue_status = GetQueueStatus(QS_SENDMESSAGE);
   if (HIWORD(queue_status) & QS_SENDMESSAGE)
     sent_messages_in_queue = true;
 
   MSG msg;
-  if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))
+  if (message_filter_->DoPeekMessage(&msg, NULL, 0, 0, PM_REMOVE))
     return ProcessMessageHelper(msg);
 
   return sent_messages_in_queue;
 }
 
-bool MessagePumpForUI::ProcessMessageHelper(const MSG& msg) {
+bool MessagePumpForUI::ProcessMessageHelper(const MSG& message) {
   TRACE_EVENT1("base", "MessagePumpForUI::ProcessMessageHelper",
-               "message", msg.message);
-  if (WM_QUIT == msg.message) {
+               "message", message.message);
+  if (WM_QUIT == message.message) {
     // Repost the QUIT message so that it will be retrieved by the primary
     // GetMessage() loop.
     state_->should_quit = true;
-    PostQuitMessage(static_cast<int>(msg.wParam));
+    PostQuitMessage(static_cast<int>(message.wParam));
     return false;
   }
 
   // While running our main message pump, we discard kMsgHaveWork messages.
-  if (msg.message == kMsgHaveWork && msg.hwnd == message_hwnd_)
+  if (message.message == kMsgHaveWork && message.hwnd == message_hwnd_)
     return ProcessPumpReplacementMessage();
 
-  if (CallMsgFilter(const_cast<MSG*>(&msg), kMessageFilterCode))
+  if (CallMsgFilter(const_cast<MSG*>(&message), kMessageFilterCode))
     return true;
 
-  WillProcessMessage(msg);
+  WillProcessMessage(message);
 
-  if (state_->dispatcher) {
-    if (!state_->dispatcher->Dispatch(msg))
-      state_->should_quit = true;
-  } else {
-    TranslateMessage(&msg);
-    DispatchMessage(&msg);
+  if (!message_filter_->ProcessMessage(message)) {

[darin (slow to review), 2012/09/06 03:56:55]

It seems like there is some overlap here between MessageFilter and
MessagePumpDispatcher.  Hmm...

+    if (state_->dispatcher) {
+      if (!state_->dispatcher->Dispatch(message))
+        state_->should_quit = true;
+    } else {
+      TranslateMessage(&message);
+      DispatchMessage(&message);
+    }
   }
 
-  DidProcessMessage(msg);
+  DidProcessMessage(message);
   return true;
 }
 
 bool MessagePumpForUI::ProcessPumpReplacementMessage() {
   // When we encounter a kMsgHaveWork message, this method is called to peek
   // and process a replacement message, such as a WM_PAINT or WM_TIMER.  The
   // goal is to make the kMsgHaveWork as non-intrusive as possible, even though
   // a continuous stream of such messages are posted.  This method carefully
   // peeks a message while there is no chance for a kMsgHaveWork to be pending,
   // then resets the have_work_ flag (allowing a replacement kMsgHaveWork to
   // possibly be posted), and finally dispatches that peeked replacement.  Note
   // that the re-post of kMsgHaveWork may be asynchronous to this thread!!
 
   bool have_message = false;
-  MSG msg;
+  MSG message;
   // We should not process all window messages if we are in the context of an
   // OS modal loop, i.e. in the context of a windows API call like MessageBox.
   // This is to ensure that these messages are peeked out by the OS modal loop.
   if (MessageLoop::current()->os_modal_loop()) {
     // We only peek out WM_PAINT and WM_TIMER here for reasons mentioned above.
-    have_message = PeekMessage(&msg, NULL, WM_PAINT, WM_PAINT, PM_REMOVE) ||
-                   PeekMessage(&msg, NULL, WM_TIMER, WM_TIMER, PM_REMOVE);
+    have_message = PeekMessage(&message, NULL, WM_PAINT, WM_PAINT, PM_REMOVE) ||
+                   PeekMessage(&message, NULL, WM_TIMER, WM_TIMER, PM_REMOVE);
   } else {
-    have_message = (0 != PeekMessage(&msg, NULL, 0, 0, PM_REMOVE));
+    have_message = !!message_filter_->DoPeekMessage(&message, NULL, 0, 0,
+                                                    PM_REMOVE);
   }
 
-  DCHECK(!have_message || kMsgHaveWork != msg.message ||
-         msg.hwnd != message_hwnd_);
+  DCHECK(!have_message || kMsgHaveWork != message.message ||
+         message.hwnd != message_hwnd_);
 
   // Since we discarded a kMsgHaveWork message, we must update the flag.
   int old_have_work = InterlockedExchange(&have_work_, 0);
   DCHECK(old_have_work);
 
   // We don't need a special time slice if we didn't have_message to process.
   if (!have_message)
     return false;
 
   // Guarantee we'll get another time slice in the case where we go into native
   // windows code.   This ScheduleWork() may hurt performance a tiny bit when
   // tasks appear very infrequently, but when the event queue is busy, the
   // kMsgHaveWork events get (percentage wise) rarer and rarer.
   ScheduleWork();
-  return ProcessMessageHelper(msg);
+  return ProcessMessageHelper(message);
+}
+
+void MessagePumpForUI::SetMessageFilter(MessageFilter *message_filter) {
+  message_filter_.reset(message_filter);
 }
 
 //-----------------------------------------------------------------------------
 // MessagePumpForIO public:
 
 MessagePumpForIO::MessagePumpForIO() {
   port_.Set(CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, NULL, 1));
   DCHECK(port_.IsValid());
 }
 
@@ skipping 208 matching lines @@
 
 // static
 MessagePumpForIO::IOHandler* MessagePumpForIO::KeyToHandler(
     ULONG_PTR key,
     bool* has_valid_io_context) {
   *has_valid_io_context = ((key & 1) == 0);
   return reinterpret_cast<IOHandler*>(key & ~static_cast<ULONG_PTR>(1));
 }
 
 }  // namespace base