chrome/browser/ui/libgtk2ui/g_object_destructor_filo.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/browser/ui/libgtk2ui/g_object_destructor_filo.h"
   6
   7 #include <glib-object.h>
   8
   9 #include "base/logging.h"
  10 #include "base/memory/singleton.h"
  11
  12 namespace libgtk2ui {
  13
  14 GObjectDestructorFILO::GObjectDestructorFILO() {
  15 }
  16
  17 GObjectDestructorFILO::~GObjectDestructorFILO() {
  18   // Probably CHECK(handler_map_.empty()) would look natural here. But
  19   // some tests (some views_unittests) violate this assertion.
  20 }
  21
  22 // static
  23 GObjectDestructorFILO* GObjectDestructorFILO::GetInstance() {
  24   return base::Singleton<GObjectDestructorFILO>::get();
  25 }
  26
  27 void GObjectDestructorFILO::Connect(
  28     GObject* object, DestructorHook callback, void* context) {
  29   const Hook hook(object, callback, context);
  30   HandlerMap::iterator iter = handler_map_.find(object);
  31   if (iter == handler_map_.end()) {
  32     g_object_weak_ref(object, WeakNotifyThunk, this);
  33     handler_map_[object].push_front(hook);
  34   } else {
  35     iter->second.push_front(hook);
  36   }
  37 }
  38
  39 void GObjectDestructorFILO::Disconnect(
  40     GObject* object, DestructorHook callback, void* context) {
  41   HandlerMap::iterator iter = handler_map_.find(object);
  42   if (iter == handler_map_.end()) {
  43     LOG(DFATAL) << "Unable to disconnect destructor hook for object " << object
  44                 << ": hook not found (" << callback << ", " << context << ").";
  45     return;
  46   }
  47   HandlerList& dtors = iter->second;
  48   if (dtors.empty()) {
  49     LOG(DFATAL) << "Destructor list is empty for specified object " << object
  50                 << " Maybe it is being executed?";
  51     return;
  52   }
  53   if (!dtors.front().equal(object, callback, context)) {
  54     // Reenable this warning once this bug is fixed:
  55     // http://code.google.com/p/chromium/issues/detail?id=85603
  56     DVLOG(1) << "Destructors should be unregistered the reverse order they "
  57              << "were registered. But for object " << object << " "
  58              << "deleted hook is "<< context << ", the last queued hook is "
  59              << dtors.front().context;
  60   }
  61   for (HandlerList::iterator i = dtors.begin(); i != dtors.end(); ++i) {
  62     if (i->equal(object, callback, context)) {
  63       dtors.erase(i);
  64       break;
  65     }
  66   }
  67   if (dtors.empty()) {
  68     g_object_weak_unref(object, WeakNotifyThunk, this);
  69     handler_map_.erase(iter);
  70   }
  71 }
  72
  73 void GObjectDestructorFILO::WeakNotify(GObject* where_the_object_was) {
  74   HandlerMap::iterator iter = handler_map_.find(where_the_object_was);
  75   DCHECK(iter != handler_map_.end());
  76   DCHECK(!iter->second.empty());
  77
  78   // Save destructor list for given object into local copy to avoid reentrancy
  79   // problem: if callee wants to modify the caller list.
  80   HandlerList dtors;
  81   iter->second.swap(dtors);
  82   handler_map_.erase(iter);
  83
  84   // Execute hooks in local list in FILO order.
  85   for (HandlerList::iterator i = dtors.begin(); i != dtors.end(); ++i)
  86     i->callback(i->context, where_the_object_was);
  87 }
  88
  89 }  // namespace libgtk2ui