Add RecycledObjectPool

Builds/VisualStudio2012/beast.vcxproj

@@ -164,6 +164,7 @@
     <ClInclude Include="..\..\modules\beast_core\memory\beast_MemoryAlignment.h" />
     <ClInclude Include="..\..\modules\beast_core\memory\beast_MemoryBlock.h" />
     <ClInclude Include="..\..\modules\beast_core\memory\beast_OptionalScopedPointer.h" />
+    <ClInclude Include="..\..\modules\beast_core\memory\beast_RecycledObjectPool.h" />
     <ClInclude Include="..\..\modules\beast_core\memory\beast_SharedObject.h" />
     <ClInclude Include="..\..\modules\beast_core\memory\beast_ScopedPointer.h" />
     <ClInclude Include="..\..\modules\beast_core\memory\beast_SharedSingleton.h" />

Builds/VisualStudio2012/beast.vcxproj.filters

@@ -629,6 +629,9 @@
     <ClInclude Include="..\..\modules\beast_core\diagnostic\beast_UnitTestUtilities.h">
       <Filter>beast_core\diagnostic</Filter>
     </ClInclude>
+    <ClInclude Include="..\..\modules\beast_core\memory\beast_RecycledObjectPool.h">
+      <Filter>beast_core\memory</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="..\..\modules\beast_core\beast_core.cpp">

TODO.txt

@@ -2,6 +2,8 @@
 BEAST TODO
 --------------------------------------------------------------------------------
 
+- Macro for acquiring a ScopedLock that records file and line.
+
 - Rename HeapBlock routines to not conflict with _CRTDBG_MAP_ALLOC macros
 
 - Design a WeakPtr / SharedPtr / SharedObject intrusive system

modules/beast_core/beast_core.h

@@ -276,6 +276,7 @@ namespace beast
 #include "memory/beast_WeakReference.h"
 #include "memory/beast_MemoryAlignment.h"
 #include "memory/beast_CacheLine.h"
+#include "memory/beast_RecycledObjectPool.h"
 #include "misc/beast_Result.h"
 #include "misc/beast_Uuid.h"
 #include "misc/beast_WindowsRegistry.h"

modules/beast_core/memory/beast_RecycledObjectPool.h

@@ -0,0 +1,126 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of Beast: https://github.com/vinniefalco/Beast
+    Copyright 2013, Vinnie Falco <vinnie.falco@gmail.com>
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#ifndef BEAST_RECYCLEDOBJECTPOOL_H_INCLUDED
+#define BEAST_RECYCLEDOBJECTPOOL_H_INCLUDED
+
+/** A pool of objects which may be recycled.
+
+    This is a thread safe pool of objects that get re-used. It is
+    primarily designed to eliminate the need for many memory allocations
+    and frees when temporary buffers are needed for operations.
+
+    To use it, first declare a structure containing the information
+    that you want to recycle. Then when you want to use a recycled object
+    put a ScopedItem on your stack:
+
+    @code
+
+    struct StdString
+    {
+        std::string data;
+    };
+
+    RecycledObjectPool <StdString> pool;
+
+    void foo ()
+    {
+        RecycledObjectPool <StdString>::ScopedItem item;
+
+        item.getObject ().data = "text";
+    }
+
+    @endcode
+*/
+template <class Object>
+class RecycledObjectPool
+{
+public:
+    struct Item : Object, LockFreeStack <Item>::Node, LeakChecked <Item>
+    {
+    };
+
+    class ScopedItem
+    {
+    public:
+        explicit ScopedItem (RecycledObjectPool <Object>& pool)
+            : m_pool (pool)
+            , m_item (pool.get ())
+        {
+        }
+
+        ~ScopedItem ()
+        {
+            m_pool.release (m_item);
+        }
+
+        Object& getObject () noexcept
+        {
+            return *m_item;
+        }
+
+    private:
+        RecycledObjectPool <Object>& m_pool;
+        Item* const m_item;
+    };
+
+public:
+    RecycledObjectPool () noexcept
+    {
+    }
+
+    ~RecycledObjectPool ()
+    {
+        for (;;)
+        {
+            Item* const item = m_stack.pop_front ();
+
+            if (item != nullptr)
+                delete item;
+            else
+                break;
+        }
+    }
+
+private:
+    Item* get ()
+    {
+        Item* item = m_stack.pop_front ();
+
+        if (item == nullptr)
+        {
+            item = new Item;
+
+            if (item == nullptr)
+                Throw (std::bad_alloc ());
+        }
+
+        return item;
+    }
+
+    void release (Item* item) noexcept
+    {
+        m_stack.push_front (item);
+    }
+
+private:
+    LockFreeStack <Item> m_stack;
+};
+
+#endif