Making sure that base::MessagePumpForUI from different modules are isolated from each other.

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/message_loop.h"
 #include "base/metrics/histogram.h"
+#include "base/process_util.h"
 #include "base/win/wrapped_window_proc.h"
 
 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() {
+MessagePumpForUI::MessagePumpForUI() : instance_(NULL) {
   InitMessageWnd();
 }
 
 MessagePumpForUI::~MessagePumpForUI() {
   DestroyWindow(message_hwnd_);
-  UnregisterClass(kWndClass, GetModuleHandle(NULL));
+  UnregisterClass(kWndClass, instance_);
 }
 
 void MessagePumpForUI::ScheduleWork() {
   if (InterlockedExchange(&have_work_, 1))
     return;  // Someone else continued the pumping.
 
   // Make sure the MessagePump does some work for us.
   PostMessage(message_hwnd_, kMsgHaveWork, reinterpret_cast<WPARAM>(this), 0);
 }
 
@@ skipping 121 matching lines @@
       break;
 
     if (more_work_is_plausible)
       continue;
 
     WaitForWork();  // Wait (sleep) until we have work to do again.
   }
 }
 
 void MessagePumpForUI::InitMessageWnd() {
-  HINSTANCE hinst = GetModuleHandle(NULL);
-
   WNDCLASSEX wc = {0};
   wc.cbSize = sizeof(wc);
   wc.lpfnWndProc = base::win::WrappedWindowProc<WndProcThunk>;
-  wc.hInstance = hinst;
+  wc.hInstance = base::GetModuleFromAddress(wc.lpfnWndProc);
   wc.lpszClassName = kWndClass;
+  instance_ = wc.hInstance;
   RegisterClassEx(&wc);
 
   message_hwnd_ =
-      CreateWindow(kWndClass, 0, 0, 0, 0, 0, 0, HWND_MESSAGE, 0, hinst, 0);
+      CreateWindow(kWndClass, 0, 0, 0, 0, 0, 0, HWND_MESSAGE, 0, instance_, 0);
   DCHECK(message_hwnd_);
 }
 
 void MessagePumpForUI::WaitForWork() {
   // Wait until a message is available, up to the time needed by the timer
   // manager to fire the next set of timers.
   int delay = GetCurrentDelay();
   if (delay < 0)  // Negative value means no timers waiting.
     delay = INFINITE;
 
@@ skipping 320 matching lines @@
 
 void MessagePumpForIO::WillProcessIOEvent() {
   FOR_EACH_OBSERVER(IOObserver, io_observers_, WillProcessIOEvent());
 }
 
 void MessagePumpForIO::DidProcessIOEvent() {
   FOR_EACH_OBSERVER(IOObserver, io_observers_, DidProcessIOEvent());
 }
 
 }  // namespace base