/**/ /* *****************
RecalcChunkMemorySize
***************** */
bool ?CMemoryPool::RecalcChunkMemorySize(SMemoryChunk? * ptrChunk,?
??????????????????unsigned? int ?uiChunkCount)
... {
??unsigned? int ?uiMemOffSet? = ? 0 ?;
?? for (unsigned? int ?i? = ? 0 ;?i? < ?uiChunkCount;?i ++ )
?? ... {
???? if (ptrChunk)
???? ... {
??????uiMemOffSet? = ?(i? * ?((unsigned? int )?m_sMemoryChunkSize))?;
??????ptrChunk -> DataSize? = ?
????????(((unsigned? int )?m_sTotalMemoryPoolSize)? - ?uiMemOffSet)?;
??????ptrChunk? = ?ptrChunk -> Next?;
????}
???? else
???? ... {
?????assert( false ? && ? " Error?:?ptrChunk?==?NULL " )?;
????? return ? false ?;
????}
??}
?? return ? true ?;
}

/**/ /* *****************
GetMemory
***************** */
void ? * CMemoryPool::GetMemory( const ?std::size_t? & sMemorySize)
... {
??std::size_t?sBestMemBlockSize? = ?CalculateBestMemoryBlockSize(sMemorySize)?;??
??SMemoryChunk? * ptrChunk? = ?NULL?;
?? while ( ! ptrChunk)
?? ... {
???? // ?Is?a?Chunks?available?to?hold?the?requested?amount?of?Memory??
????ptrChunk? = ?FindChunkSuitableToHoldMemory(sBestMemBlockSize)?;
???? if ?( ! ptrChunk)
???? ... {
?????? // ?No?chunk?can?be?found
?????? // ?=>?Memory-Pool?is?to?small.?We?have?to?request?
?????? // ????more?Memory?from?the?Operating-System....
??????sBestMemBlockSize? = ?MaxValue(sBestMemBlockSize,?
????????CalculateBestMemoryBlockSize(m_sMinimalMemorySizeToAllocate))?;
??????AllocateMemory(sBestMemBlockSize)?;
????}
??}

?? // ?Finally,?a?suitable?Chunk?was?found.
?? // ?Adjust?the?Values?of?the?internal?"TotalSize"/"UsedSize"?Members?and?
?? // ?the?Values?of?the?MemoryChunk?itself.
??m_sUsedMemoryPoolSize? += ?sBestMemBlockSize?;
??m_sFreeMemoryPoolSize? -= ?sBestMemBlockSize?;
??m_uiObjectCount ++ ?;
??SetMemoryChunkValues(ptrChunk,?sBestMemBlockSize)?;

?? // ?eventually,?return?the?Pointer?to?the?User
?? return ?(( void ? * )?ptrChunk -> Data)?;
}

/**/ /* *****************
????SetMemoryChunkValues
????***************** */
void ?CMemoryPool::SetMemoryChunkValues(SMemoryChunk? * ptrChunk,?
????? const ?std::size_t? & sMemBlockSize)
... {
?? if (ptrChunk)?
?? ... {
????ptrChunk -> UsedSize? = ?sMemBlockSize?;
??}
??...
????} ?

• CMemoryPool.h
• CMemoryPool.cpp
• IMemoryBlock.h
• SMemoryChunk.h

MemPool::CMemoryPool? * g_ptrMemPool? = ? new ?MemPool::CMemoryPool()?;
char ? * ptrCharArray? = ?( char ? * )?g_ptrMemPool -> GetMemory( 100 )?;
...
g_ptrMemPool -> FreeMemory(ptrCharArray,? 100 )?;
delete?g_ptrMemPool?;

/**/ /* *****************
Constructor
***************** */
MyTestClass::MyTestClass()
... {
???m_cMyArray[ 0 ]? = ? ' H ' ?;
???m_cMyArray[ 1 ]? = ? ' e ' ?;
???m_cMyArray[ 2 ]? = ? ' l ' ?;
???m_cMyArray[ 3 ]? = ? ' l ' ?;
???m_cMyArray[ 4 ]? = ? ' o ' ?;
???m_cMyArray[ 5 ]? = ?NULL?;
???m_strMyString? = ? " This?is?a?small?Test-String " ?;
???m_iMyInt? = ? 12345 ?;

???m_fFloatValue? = ? 23456.7890f ?;
???m_fDoubleValue? = ? 6789.012345 ?;

???Next? = ? this ?;
}

MyTestClass? * ptrTestClass? = ? new ?MyTestClass?;?
g_ptrMemPool -> WriteMemoryDumpToFile( " MemoryDump.bin " )?;

// Array-test?(Memory?Pool):?
for (unsigned? int ?j? = ? 0 ;?j? < ?TestCount;?j ++ )
... {
???????? // ?ArraySize?=?1000
???? char ? * ptrArray? = ?( char ? * )?g_ptrMemPool -> GetMemory(ArraySize)??;
????g_ptrMemPool -> FreeMemory(ptrArray,?ArraySize)?;
}
??
???? // Array-test?(Heap):
for (unsigned? int ?j? = ? 0 ;?j? < ?TestCount;?j ++ )
... {
???????? // ?ArraySize?=?1000
???? char ? * ptrArray? = ?( char ? * )?malloc(ArraySize)??;
????free(ptrArray)?;
???}

? // Class-Test?for?MemoryPool?and?Heap?(overloaded?new/delete)?
for (unsigned? int ?j? = ? 0 ;?j? < ?TestCount;?j ++ )
... {
????MyTestClass? * ptrTestClass? = ? new ?MyTestClass?;
????delete?ptrTestClass?;
}

• Microsoft Visual C++ 6.0
• Microsoft Visual C++ .NET 2003
• MinGW (GCC) 3.4.4 (Windows)
• GCC 4.0.X (Debian GNU Linux)

【譯】C++ 內(nèi)存池 -- C++ Memory Pool .