base/supports_user_data.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 "base/supports_user_data.h"
   6
   7 namespace base {
   8
   9 SupportsUserData::SupportsUserData() {
  10   // Harmless to construct on a different thread to subsequent usage.
  11   thread_checker_.DetachFromThread();
  12 }
  13
  14 SupportsUserData::Data* SupportsUserData::GetUserData(const void* key) const {
  15   DCHECK(thread_checker_.CalledOnValidThread());
  16   DataMap::const_iterator found = user_data_.find(key);
  17   if (found != user_data_.end())
  18     return found->second.get();
  19   return NULL;
  20 }
  21
  22 void SupportsUserData::SetUserData(const void* key, Data* data) {
  23   DCHECK(thread_checker_.CalledOnValidThread());
  24   user_data_[key] = linked_ptr<Data>(data);
  25 }
  26
  27 void SupportsUserData::RemoveUserData(const void* key) {
  28   DCHECK(thread_checker_.CalledOnValidThread());
  29   user_data_.erase(key);
  30 }
  31
  32 void SupportsUserData::DetachUserDataThread() {
  33   thread_checker_.DetachFromThread();
  34 }
  35
  36 SupportsUserData::~SupportsUserData() {
  37   DCHECK(thread_checker_.CalledOnValidThread() || user_data_.empty());
  38   DataMap local_user_data;
  39   user_data_.swap(local_user_data);
  40   // Now this->user_data_ is empty, and any destructors called transitively from
  41   // the destruction of |local_user_data| will see it that way instead of
  42   // examining a being-destroyed object.
  43 }
  44
  45 }  // namespace base