内存池版本4--多线程-可变大小对象的内存池

#include "stdafx.h"
#include <windows.h>
#include <MMSystem.h>
#include <iostream>
using namespace std;

#pragma comment(lib, "winmm.lib")

class Foo
{
public:
    Foo(int a = 0, int b = 0):m(a), n(b) {}

private:
    int m;
    int n;
};


///////////////////////////////////////////////////////////

template <typename T>
class MemoryPool
{
public:
    MemoryPool(size_t size = EXPAND_SIZE)
    {
        ExpandFreeList(size);
    }

    ~MemoryPool()
    {
        if (pNext != 0)
        {
            MemoryPool<T>* ptr = pNext;
            for (; ptr != NULL; ptr = pNext)    
            {
                pNext = pNext->pNext;
                delete []ptr;
            }
        }
    }

    inline void* alloc(size_t size) //分配一个T类型的对象
    {
        if (pNext == 0)
        {
            ExpandFreeList(EXPAND_SIZE);
        }

        MemoryPool<T>* ptr = pNext;
        pNext = pNext->pNext;
        return ptr;
    }

    inline void  free(void* doomed) //释放一个T类型的指针
    {
        MemoryPool<T>* ptr = static_cast<MemoryPool<T>* >(doomed);
        ptr->pNext = pNext;
        pNext = ptr;
    }

    //private:
    enum {EXPAND_SIZE = 3};
    MemoryPool<T>* pNext;

    void ExpandFreeList(size_t num = EXPAND_SIZE)
    {
        size_t size = sizeof(T) > sizeof(MemoryPool<T>*) ? sizeof(T) :  sizeof(MemoryPool<T>*);
        MemoryPool<T>* ptr = (MemoryPool<T>*)(new char[size]);
        pNext = ptr;
        for (int i=0; i<num; ++i)
        {
            ptr->pNext = (MemoryPool<T>*)(new char[size]);
            ptr = ptr->pNext;
        }

        ptr->pNext = 0;
    }
};

///////////////////////////////////////////////


template <class POOLTYPE, class LOCK>
class MTMeomoryPool
{
public:
    MTMeomoryPool() {}
    ~MTMeomoryPool() {}

    void* alloc(size_t size)
    {
        lock_.lock();
        void* pMem = pool_.alloc(size);
        lock_.unlock();
        return pMem;
    }

    void free(void* doomed)
    {
        lock_.lock();
        pool_.free(doomed);
        lock_.unlock();
    }

private:
    POOLTYPE pool_;
    LOCK     lock_;
};

/////////////////////////////////////////////////

class ABCLock
{
public:
    virtual ~ABCLock() {}
    virtual void lock() = 0;
    virtual void unlock() = 0;
};

class MutexLock : public ABCLock
{
public:
    MutexLock()
    {
        create(TEXT("mutex"));
    }

    ~MutexLock()
    {
        release();
    }

    void lock()
    {
        wait();
    }

    void unlock()
    {
    }

private:
    HANDLE mutex_;

    bool create( const std::wstring& str)
    {
        mutex_ = ::CreateMutex(NULL, FALSE, str.c_str());
        if (mutex_ == NULL || ::GetLastError() == ERROR_ALREADY_EXISTS)
            return false;
        else
            return true;
    }

    bool wait()
    {
        UINT32 ret = ::WaitForSingleObject(mutex_, 0);
        if (WAIT_FAILED == ret || WAIT_TIMEOUT == ret)
            return false;
        else
            return true;
    }

    void release()
    {
        if (mutex_ != NULL)
        {
            ReleaseMutex(mutex_);
            CloseHandle(mutex_);
            mutex_ = NULL;
        }
    }
};

class CSLock : public ABCLock
{
public:
    CSLock()
    {
        InitializeCriticalSection(&cs_);
    }

    ~CSLock()
    {
        DeleteCriticalSection(&cs_);
    }

    void lock()
    {
        EnterCriticalSection(&cs_);
    }

    void unlock()
    {
        LeaveCriticalSection(&cs_);
    }

private:
    CRITICAL_SECTION cs_;
};

/////////////////////////////////////////////////////

class Foo4
{
public:
    Foo4(int a =0, int b = 0):m_(a), n_(b){}

    static void NewMemoryPool()
    {
        pool_ = new MTMeomoryPool<MemoryPool<Foo4>, CSLock>;
    }

    static void DeleteMemoryPool()
    {
        delete pool_;
    }

private:
    int m_;
    int n_;

    static MTMeomoryPool< MemoryPool<Foo4>, CSLock>* pool_;
};

MTMeomoryPool< MemoryPool<Foo4>, CSLock>* Foo4::pool_ = 0;

////////////////////////////////////////////////////////////////

int main()
{
    DWORD time1, time2, deltaTime;
    time1 = timeGetTime();
    for (int i=0; i<500; ++i)
    {
        Foo* ptrArray[1000];
        for (int j=0; j<1000; ++j)
        {
            ptrArray[j] = new Foo;
        }

        for (int j=0; j<1000; ++j)
        {
            delete ptrArray[j];
        }
    }

    time2 = timeGetTime();
    deltaTime = time2- time1;
    cout<<deltaTime<<endl;

    Foo4::NewMemoryPool();
    time1 = timeGetTime();
    for (int i=0; i<500; ++i)
    {
        Foo4* ptrArray[1000];
        for (int j=0; j<1000; ++j)
        {
            ptrArray[j] = new Foo4;
        }

        for (int j=0; j<1000; ++j)
        {
            delete ptrArray[j];
        }
    }

    time2 = timeGetTime();
    Foo4::DeleteMemoryPool();
    deltaTime = time2- time1;
    cout<<deltaTime<<endl;

    return 0;
}