mirror of
https://github.com/pocoproject/poco.git
synced 2024-12-16 19:54:38 +01:00
116 lines
2.2 KiB
C++
116 lines
2.2 KiB
C++
//
|
|
// MemoryPool.h
|
|
//
|
|
// Library: Foundation
|
|
// Package: Core
|
|
// Module: MemoryPool
|
|
//
|
|
// Definition of the MemoryPool class.
|
|
//
|
|
// Copyright (c) 2005-2006, Applied Informatics Software Engineering GmbH.
|
|
// and Contributors.
|
|
//
|
|
// SPDX-License-Identifier: BSL-1.0
|
|
//
|
|
|
|
|
|
#ifndef Foundation_MemoryPool_INCLUDED
|
|
#define Foundation_MemoryPool_INCLUDED
|
|
|
|
|
|
#include "Poco/Foundation.h"
|
|
#include "Poco/Mutex.h"
|
|
#include <vector>
|
|
#include <cstddef>
|
|
|
|
|
|
namespace Poco {
|
|
|
|
|
|
class Foundation_API MemoryPool
|
|
/// A simple pool for fixed-size memory blocks.
|
|
///
|
|
/// The main purpose of this class is to speed-up
|
|
/// memory allocations, as well as to reduce memory
|
|
/// fragmentation in situations where the same blocks
|
|
/// are allocated all over again, such as in server
|
|
/// applications.
|
|
///
|
|
/// All allocated blocks are retained for future use.
|
|
/// A limit on the number of blocks can be specified.
|
|
/// Blocks can be preallocated.
|
|
{
|
|
public:
|
|
MemoryPool(std::size_t blockSize, int preAlloc = 0, int maxAlloc = 0);
|
|
/// Creates a MemoryPool for blocks with the given blockSize.
|
|
/// The number of blocks given in preAlloc are preallocated.
|
|
|
|
~MemoryPool();
|
|
|
|
void* get();
|
|
/// Returns a memory block. If there are no more blocks
|
|
/// in the pool, a new block will be allocated.
|
|
///
|
|
/// If maxAlloc blocks are already allocated, an
|
|
/// OutOfMemoryException is thrown.
|
|
|
|
void release(void* ptr);
|
|
/// Releases a memory block and returns it to the pool.
|
|
|
|
std::size_t blockSize() const;
|
|
/// Returns the block size.
|
|
|
|
int allocated() const;
|
|
/// Returns the number of allocated blocks.
|
|
|
|
int available() const;
|
|
/// Returns the number of available blocks in the pool.
|
|
|
|
private:
|
|
MemoryPool();
|
|
MemoryPool(const MemoryPool&);
|
|
MemoryPool& operator = (const MemoryPool&);
|
|
|
|
void clear();
|
|
|
|
enum
|
|
{
|
|
BLOCK_RESERVE = 128
|
|
};
|
|
|
|
typedef std::vector<char*> BlockVec;
|
|
|
|
std::size_t _blockSize;
|
|
int _maxAlloc;
|
|
int _allocated;
|
|
BlockVec _blocks;
|
|
FastMutex _mutex;
|
|
};
|
|
|
|
|
|
//
|
|
// inlines
|
|
//
|
|
inline std::size_t MemoryPool::blockSize() const
|
|
{
|
|
return _blockSize;
|
|
}
|
|
|
|
|
|
inline int MemoryPool::allocated() const
|
|
{
|
|
return _allocated;
|
|
}
|
|
|
|
|
|
inline int MemoryPool::available() const
|
|
{
|
|
return (int) _blocks.size();
|
|
}
|
|
|
|
|
|
} // namespace Poco
|
|
|
|
|
|
#endif // Foundation_MemoryPool_INCLUDED
|