base/memory/ref_counted.cc

   1 // Copyright (c) 2011 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/memory/ref_counted.h"
   6 #include "base/threading/thread_collision_warner.h"
   7
   8 namespace base {
   9
  10 namespace subtle {
  11
  12 bool RefCountedThreadSafeBase::HasOneRef() const {
  13   return AtomicRefCountIsOne(
  14       &const_cast<RefCountedThreadSafeBase*>(this)->ref_count_);
  15 }
  16
  17 RefCountedThreadSafeBase::RefCountedThreadSafeBase() : ref_count_(0) {
  18 #ifndef NDEBUG
  19   in_dtor_ = false;
  20 #endif
  21 }
  22
  23 RefCountedThreadSafeBase::~RefCountedThreadSafeBase() {
  24 #ifndef NDEBUG
  25   DCHECK(in_dtor_) << "RefCountedThreadSafe object deleted without "
  26                       "calling Release()";
  27 #endif
  28 }
  29
  30 void RefCountedThreadSafeBase::AddRef() const {
  31 #ifndef NDEBUG
  32   DCHECK(!in_dtor_);
  33 #endif
  34   AtomicRefCountInc(&ref_count_);
  35 }
  36
  37 bool RefCountedThreadSafeBase::Release() const {
  38 #ifndef NDEBUG
  39   DCHECK(!in_dtor_);
  40   DCHECK(!AtomicRefCountIsZero(&ref_count_));
  41 #endif
  42   if (!AtomicRefCountDec(&ref_count_)) {
  43 #ifndef NDEBUG
  44     in_dtor_ = true;
  45 #endif
  46     return true;
  47   }
  48   return false;
  49 }
  50
  51 }  // namespace subtle
  52
  53 }  // namespace base