Schedule an APC to trigger the thread cap

chrome/app/chrome_exe_main_win.cc

 // Copyright (c) 2011 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 <windows.h>
 #include <tchar.h>
 
 #include "base/at_exit.h"
 #include "base/command_line.h"
 #include "chrome/app/breakpad_win.h"
 #include "chrome/app/client_util.h"
 #include "chrome/app/metro_driver_win.h"
 #include "content/public/app/startup_helper_win.h"
 #include "content/public/common/result_codes.h"
 #include "sandbox/win/src/sandbox_factory.h"
 
 namespace {
 
 // TODO(jschuh): Remove this after we narrow down the cause of the crashes.
 class ThreadTracker {
  public:
   static void NTAPI UpdateCount(PVOID module, DWORD reason, PVOID reserved) {
     if (reason == DLL_THREAD_ATTACH) {
+      // We hit the threshold, but the loader would eat an exception fired now.
+      // So schedule an APC to fire the exception once loading is done.
       if (::InterlockedIncrement(&count_) > cap_)
-        __debugbreak();
+        ::QueueUserAPC(CrashProcessCallback, ::GetCurrentThread(), NULL);
     } else if (reason == DLL_THREAD_DETACH) {
       ::InterlockedDecrement(&count_);
     }
   }
 
   static void SetCap(LONG cap) { cap_ = cap; }
 
  private:
-  static LONG volatile count_;
-  static LONG volatile cap_;
+  static void CALLBACK CrashProcessCallback(ULONG_PTR) { __debugbreak(); }
+
+  static volatile LONG count_;
+  static volatile LONG cap_;
 };
 
 LONG volatile ThreadTracker::count_ = 1;
 LONG volatile ThreadTracker::cap_ = LONG_MAX;
 
 }  // namespace
 
 // Magic required to get our function called on thread attach and detach.
 extern "C" {
 #pragma data_seg(push, old_seg)
@@ skipping 34 matching lines @@
   CommandLine::Init(0, NULL);
   // The exit manager is in charge of calling the dtors of singletons.
   base::AtExitManager exit_manager;
 
   MetroDriver metro_driver;
   if (metro_driver.in_metro_mode())
     return metro_driver.RunInMetro(instance, &RunChrome);
   // Not in metro mode, proceed as normal.
   return RunChrome(instance);
 }