| /* |
| * Copyright (C) 2006, 2007 Apple Inc. All rights reserved. |
| * |
| * This library is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Library General Public |
| * License as published by the Free Software Foundation; either |
| * version 2 of the License, or (at your option) any later version. |
| * |
| * This library is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Library General Public License for more details. |
| * |
| * You should have received a copy of the GNU Library General Public License |
| * along with this library; see the file COPYING.LIB. If not, write to |
| * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, |
| * Boston, MA 02110-1301, USA. |
| * |
| */ |
| |
| #ifndef TreeShared_h |
| #define TreeShared_h |
| |
| #include <wtf/Assertions.h> |
| #include <wtf/Noncopyable.h> |
| |
| namespace WebCore { |
| |
| template<class T> class TreeShared : Noncopyable { |
| public: |
| TreeShared() |
| : m_refCount(0) |
| , m_parent(0) |
| { |
| #ifndef NDEBUG |
| m_deletionHasBegun = false; |
| m_inRemovedLastRefFunction = false; |
| #endif |
| } |
| TreeShared(T* parent) |
| : m_refCount(0) |
| , m_parent(0) |
| { |
| #ifndef NDEBUG |
| m_deletionHasBegun = false; |
| m_inRemovedLastRefFunction = false; |
| #endif |
| } |
| virtual ~TreeShared() |
| { |
| ASSERT(m_deletionHasBegun); |
| } |
| |
| void ref() |
| { |
| ASSERT(!m_deletionHasBegun); |
| ASSERT(!m_inRemovedLastRefFunction); |
| ++m_refCount; |
| } |
| |
| void deref() |
| { |
| ASSERT(!m_deletionHasBegun); |
| ASSERT(!m_inRemovedLastRefFunction); |
| if (--m_refCount <= 0 && !m_parent) { |
| #ifndef NDEBUG |
| m_inRemovedLastRefFunction = true; |
| #endif |
| removedLastRef(); |
| } |
| } |
| |
| bool hasOneRef() const |
| { |
| ASSERT(!m_deletionHasBegun); |
| ASSERT(!m_inRemovedLastRefFunction); |
| return m_refCount == 1; |
| } |
| |
| int refCount() const |
| { |
| return m_refCount; |
| } |
| |
| void setParent(T* parent) { m_parent = parent; } |
| T* parent() const { return m_parent; } |
| |
| #ifndef NDEBUG |
| bool m_deletionHasBegun; |
| bool m_inRemovedLastRefFunction; |
| #endif |
| |
| private: |
| virtual void removedLastRef() |
| { |
| #ifndef NDEBUG |
| m_deletionHasBegun = true; |
| #endif |
| delete this; |
| } |
| |
| int m_refCount; |
| T* m_parent; |
| }; |
| |
| } |
| |
| #endif // TreeShared.h |