Initial revision

intern/memutil/MEM_RefCounted.h

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+/**
+ * $Id$
+ * ***** BEGIN GPL/BL DUAL LICENSE BLOCK *****
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version. The Blender
+ * Foundation also sells licenses for use in proprietary software under
+ * the Blender License.  See http://www.blender.org/BL/ for information
+ * about this.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ *
+ * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
+ * All rights reserved.
+ *
+ * The Original Code is: all of this file.
+ *
+ * Contributor(s): none yet.
+ *
+ * ***** END GPL/BL DUAL LICENSE BLOCK *****
+ */
+
+/**
+
+ * $Id$
+ * Copyright (C) 2001 NaN Technologies B.V.
+ * @author	Maarten Gribnau
+ * @date	March 31, 2001
+ */
+
+#ifndef _H_MEM_REF_COUNTED
+#define _H_MEM_REF_COUNTED
+
+
+/**
+ * An object with reference counting.
+ * Base class for objects with reference counting.
+ * When a shared object is ceated, it has reference count == 1.
+ * If the the reference count of a shared object reaches zero, the object self-destructs.
+ * The default destructor of this object has been made protected on purpose.
+ * This disables the creation of shared objects on the stack.
+ *
+ * @author	Maarten Gribnau
+ * @date	March 31, 2001
+ */
+
+class MEM_RefCounted {
+public:
+	/**
+	 * Constructs a a shared object.
+	 */
+	MEM_RefCounted() : m_refCount(1)
+	{
+	}
+
+	/** 
+	 * Returns the reference count of this object.
+	 * @return the reference count.
+	 */
+	inline virtual int getRef() const;
+
+	/** 
+	 * Increases the reference count of this object.
+	 * @return the new reference count.
+	 */
+	inline virtual int incRef();
+
+	/** 
+	 * Decreases the reference count of this object.
+	 * If the the reference count reaches zero, the object self-destructs.
+	 * @return the new reference count.
+	 */
+	inline virtual int decRef();
+
+protected:
+	/**
+	 * Destructs a shared object.
+	 * The destructor is protected to force the use of incRef and decRef.
+	 */
+	virtual ~MEM_RefCounted()
+	{
+	}
+
+protected:
+	/// The reference count.
+	int m_refCount;
+};
+
+
+inline int MEM_RefCounted::getRef() const
+{
+	return m_refCount;
+}
+
+inline int MEM_RefCounted::incRef()
+{
+	return ++m_refCount;
+}
+
+inline int MEM_RefCounted::decRef()
+{
+	m_refCount--;
+	if (m_refCount == 0) {
+		delete this;
+		return 0;
+	}
+	return m_refCount;
+}
+
+
+#endif // _H_MEM_REF_COUNTED