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Diffstat (limited to 'indra/llcorehttp/_refcounted.h')
-rw-r--r-- | indra/llcorehttp/_refcounted.h | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/indra/llcorehttp/_refcounted.h b/indra/llcorehttp/_refcounted.h new file mode 100644 index 0000000000..a96c65fb6b --- /dev/null +++ b/indra/llcorehttp/_refcounted.h @@ -0,0 +1,125 @@ +/** + * @file _refcounted.h + * @brief Atomic, thread-safe ref counting and destruction mixin class + * + * $LicenseInfo:firstyear=2012&license=viewerlgpl$ + * Second Life Viewer Source Code + * Copyright (C) 2012, Linden Research, Inc. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; + * version 2.1 of the License only. + * + * 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 + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + * + * Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA + * $/LicenseInfo$ + */ + +#ifndef LLCOREINT__REFCOUNTED_H_ +#define LLCOREINT__REFCOUNTED_H_ + + +#include "linden_common.h" + +#include <boost/thread.hpp> + +#include "llapr.h" + + +namespace LLCoreInt +{ + + +class RefCounted +{ +private: + RefCounted(); // Not defined - may not be default constructed + void operator=(const RefCounted &); // Not defined + +public: + explicit RefCounted(bool const implicit) + : mRefCount(implicit) + {} + + // ref-count interface + void addRef() const; + void release() const; + bool isLastRef() const; + S32 getRefCount() const; + void noRef() const; + + static const S32 NOT_REF_COUNTED = -1; + +protected: + virtual ~RefCounted(); + virtual void destroySelf(); + +private: + mutable LLAtomicS32 mRefCount; + +}; // end class RefCounted + + +inline void RefCounted::addRef() const +{ + S32 count(mRefCount++); + llassert_always(count >= 0); +} + + +inline void RefCounted::release() const +{ + S32 count(mRefCount); + llassert_always(count != NOT_REF_COUNTED); + llassert_always(count > 0); + count = mRefCount--; + + // clean ourselves up if that was the last reference + if (0 == count) + { + const_cast<RefCounted *>(this)->destroySelf(); + } +} + + +inline bool RefCounted::isLastRef() const +{ + const S32 count(mRefCount); + llassert_always(count != NOT_REF_COUNTED); + llassert_always(count >= 1); + return (1 == count); +} + + +inline S32 RefCounted::getRefCount() const +{ + const S32 result(mRefCount); + return result; +} + + +inline void RefCounted::noRef() const +{ + llassert_always(mRefCount <= 1); + mRefCount = NOT_REF_COUNTED; +} + + +inline void RefCounted::destroySelf() +{ + delete this; +} + +} // end namespace LLCoreInt + +#endif // LLCOREINT__REFCOUNTED_H_ + |