Assert sequence validity on non-thread-safe RefCount manipulations (2)

base/at_exit.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 "base/at_exit.h"
 
 #include <stddef.h>
 #include <ostream>
 #include <utility>
 
@@ skipping 63 matching lines @@
   // Callbacks may try to add new callbacks, so run them without holding
   // |lock_|. This is an error and caught by the DCHECK in RegisterTask(), but
   // handle it gracefully in release builds so we don't deadlock.
   std::stack<base::Closure> tasks;
   {
     AutoLock lock(g_top_manager->lock_);
     tasks.swap(g_top_manager->stack_);
     g_top_manager->processing_callbacks_ = true;
   }
 
+  // Relax the cross-thread access restriction to non-thread-safe RefCount.
+  // It's safe since all other threads should be terminated at this point.
+  ScopedAllowCrossThreadRefCountAccess allow_cross_thread_ref_count_access;
+
   while (!tasks.empty()) {
     base::Closure task = tasks.top();
     task.Run();
     tasks.pop();
   }
 
   // Expect that all callbacks have been run.
   DCHECK(g_top_manager->stack_.empty());
 }
 
 void AtExitManager::DisableAllAtExitManagers() {
   AutoLock lock(g_top_manager->lock_);
   g_disable_managers = true;
 }
 
 AtExitManager::AtExitManager(bool shadow)
     : processing_callbacks_(false), next_manager_(g_top_manager) {
   DCHECK(shadow || !g_top_manager);
   g_top_manager = this;
 }
 
 }  // namespace base