experiment : 在私有堆和默认进程堆中, 测试能分配的堆空间总和, 每次能分配的最大堆空间

实验环境: Win7X64Sp1 + vs2008,  物理内存16GB.

实验结论:

    *  进程堆的最大Size并没有使用完剩余的物理内存
    *  每次能分配的最大堆空间接近2M, 不管是私有堆,还是进程堆, 和堆初始Size无关, 
    *  将堆空间用尽后, 累计堆空间总Size接近2000MB, 不管是私有堆,还是进程堆, 和堆初始Size无关,

/// @file       getHeapSize.cpp
/// @brief      尝试得到本进程堆的最大size

#include "stdafx.h"
#include <Windows.h>
#include <tchar.h>

#define MEMORY_REQUESTED_MB (1024 * 1024)       ///< 请求的堆尺寸单位(MB)
size_t  GetSystemPageSize();
bool    GetHeapSize(HANDLE hHeap, size_t & nSizeHeapOnce, size_t & nSizeHeap);
bool    GetHeapAllocTotal(HANDLE hHeap, size_t nSizeHeapOnce, size_t & nSizeHeapTotal); ///< 计算在堆上能分配的空间总和

int _tmain(int argc, _TCHAR* argv[])
{
    bool    bRc             =   false;
    int     iIndex          =   0;
    size_t  nSizeHeap       =   0;
    size_t  nSizeHeapOnce   =   0;
    size_t  nSizeHeapTotal  =   0;
    HANDLE  hHeap           =   GetProcessHeap();

    _tprintf(L"when hHeap = GetProcessHeap();
");
    for(iIndex = 0; iIndex < 5; iIndex++)
    {
        bRc = GetHeapSize(hHeap, nSizeHeapOnce, nSizeHeap);
        _tprintf(   L"GetHeapSize() = %s, nSizeHeap = 0x%X, %.3f(MB)
",
            bRc ? L"TRUE" : L"FALSE",
            nSizeHeap, 1.0f * nSizeHeap / MEMORY_REQUESTED_MB);
    }

    /// 对私有堆的测试
    nSizeHeap = MEMORY_REQUESTED_MB * 10;
    hHeap = HeapCreate(0, GetSystemPageSize() * 4, nSizeHeap);  ///< 建立10MB的私有堆, 每次提交4Page
    if(NULL == hHeap)
        _tprintf(L"HeapCreate error code = 0x%x
", GetLastError());
    else
    {
        _tprintf(L"HeapCreate Ok, nSizeHeap = %dMB
", nSizeHeap / MEMORY_REQUESTED_MB);
        for(iIndex = 0; iIndex < 5; iIndex++)
        {
            bRc = GetHeapSize(hHeap, nSizeHeapOnce, nSizeHeap);
            _tprintf(   L"GetHeapSize() = %s, nSizeHeap = 0x%X, %.3f(MB)
",
                bRc ? L"TRUE" : L"FALSE",
                nSizeHeap, 1.0f * nSizeHeap / MEMORY_REQUESTED_MB);
        }

        HeapDestroy(hHeap);
    }

    /// 测试从私有堆上能分配的最大空间, 依次分配一块, 计算能分配的空间总和
    nSizeHeap = MEMORY_REQUESTED_MB * 10;
    if(0 == nSizeHeapOnce)
        nSizeHeapOnce = GetSystemPageSize();
    _tprintf(L"nSizeHeapOnce = 0x%x
", nSizeHeapOnce);

    hHeap = HeapCreate(0, nSizeHeapOnce, nSizeHeap);    ///< 建立10MB的私有堆, 每次提交4Page
    if(NULL == hHeap)
        _tprintf(L"HeapCreate error code = 0x%x
", GetLastError());
    else
    {
        _tprintf(L"HeapCreate Ok, nSizeHeap = %dMB
", nSizeHeap / MEMORY_REQUESTED_MB);
        bRc = GetHeapAllocTotal(hHeap, nSizeHeapOnce, nSizeHeapTotal);
        _tprintf(   L"GetHeapAllocTotal() = %s, nSizeHeapOnce = 0x%X, %.3f(MB), nSizeHeapTotal = 0x%X, %.3f(MB)
",
            bRc ? L"TRUE" : L"FALSE",
            nSizeHeapOnce, 1.0f * nSizeHeapOnce / MEMORY_REQUESTED_MB,
            nSizeHeapTotal, 1.0f * nSizeHeapTotal / MEMORY_REQUESTED_MB);

        HeapDestroy(hHeap);
    }


    /** operating results
    将程序编译成Release + win32, 在IDE外直接运行

    when hHeap = GetProcessHeap();
    GetHeapSize() = TRUE, nSizeHeap = 0x70CBF000, 1804.746(MB)
    GetHeapSize() = TRUE, nSizeHeap = 0x70CBF000, 1804.746(MB)
    GetHeapSize() = TRUE, nSizeHeap = 0x70CBF000, 1804.746(MB)
    GetHeapSize() = TRUE, nSizeHeap = 0x70CBF000, 1804.746(MB)
    GetHeapSize() = TRUE, nSizeHeap = 0x70CBF000, 1804.746(MB)
    HeapCreate Ok, nSizeHeap = 10MB
    GetHeapSize() = TRUE, nSizeHeap = 0x1FF000, 1.996(MB)
    GetHeapSize() = TRUE, nSizeHeap = 0x1FF000, 1.996(MB)
    GetHeapSize() = TRUE, nSizeHeap = 0x1FF000, 1.996(MB)
    GetHeapSize() = TRUE, nSizeHeap = 0x1FF000, 1.996(MB)
    GetHeapSize() = TRUE, nSizeHeap = 0x1FF000, 1.996(MB)
    nSizeHeapOnce = 0x1ff000
    HeapCreate Ok, nSizeHeap = 10MB
    GetHeapAllocTotal() = TRUE, nSizeHeapOnce = 0x1FF000, 1.996(MB), nSizeHeapTotal
    = 0x7C41C000, 1988.109(MB)

    剩余物理内存是8655M, 看来进程堆的最大Size并没有使用完剩余的物理内存
    经过多次实验, 进程堆的Size大约是1800上下几MB

    建立10MB的私有堆, 测试出的私有堆大小为2MB左右??
    建立了20MB的私有堆, 测试出的私有堆大小也为2MB左右.
    建立了100MB的私有堆, 测试出的私有堆大小也为2MB左右.

    结论: 进程私有堆是程序编译时指定的, 指定多大都没用

    在vs2008中设置对大小为10MB, 10485760
    设置步骤: vs2008工程属性 >> Configuration Properties >> Linker >> System >> Heap Reserver Size
    实验结果:
        * 每次能分配的堆空间一直2M左右, 不管是私有堆,还是进程堆, 和堆初始Size无关,
        * 能分配的堆空间总和接近2000MB, 不管是私有堆,还是进程堆, 和堆初始Size无关,
    */

    getchar();
    return 0;
}

bool    GetHeapAllocTotal(HANDLE hHeap, size_t nSizeHeapOnce, size_t & nSizeHeapTotal)
{
    bool        bRc             =   false;
    BYTE *      pBufHeap        =   NULL;

    nSizeHeapTotal = 0;
    do
    {
        pBufHeap = static_cast<BYTE *>(HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, nSizeHeapOnce));
        if(NULL != pBufHeap)
        {
            bRc = true;
            nSizeHeapTotal += nSizeHeapOnce;
        }

    } while (NULL != pBufHeap);

    return bRc;
}

bool    GetHeapSize(HANDLE hHeap, size_t & nSizeHeapOnce, size_t & nSizeHeap)
{
    bool        bRc             =   false;
    size_t      nSystemPageSize =   GetSystemPageSize();
    int         iMultiple       =   0;          ///< 内存申请容量是SYSTEM_INFO.PageSize的倍数
    BYTE *      pBufHeap        =   NULL;

    iMultiple = static_cast<size_t>(MEMORY_REQUESTED_MB) / nSystemPageSize;
    nSizeHeap = iMultiple * nSystemPageSize;    ///< 从1MB开始尝试
    do
    {
        pBufHeap = static_cast<BYTE *>(HeapAlloc(hHeap, HEAP_ZERO_MEMORY, nSizeHeap));
        if(NULL != pBufHeap)
        {
            if(FALSE == HeapFree(GetProcessHeap(), 0, pBufHeap))
                return false;
        }

        iMultiple *= 2; ///< 快速靠近堆上限制
        nSizeHeap = iMultiple * nSystemPageSize;
    } while (NULL != pBufHeap); ///< 一直尝试到失败为止

    /// 从失败的最大Size往小申请, 第一次成功的Size就是进程堆的Size
    nSizeHeap = --iMultiple * nSystemPageSize;
    do
    {
        pBufHeap = static_cast<BYTE *>(HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, nSizeHeap));
        if(NULL != pBufHeap)
        {
            if(FALSE == HeapFree(GetProcessHeap(), 0, pBufHeap))
            {
                return false;
            }

            bRc = true;
            nSizeHeapOnce = nSizeHeap;
            break;
        }

        nSizeHeap = --iMultiple * nSystemPageSize;
    } while (NULL == pBufHeap); ///< 一直尝试到成功为止

    return bRc;
}

size_t  GetSystemPageSize()
{
    /// SYSTEM_INFO.dwPageSize : 页面大小和页保护和承诺的粒度, 是VirtualAlloc的入参

    SYSTEM_INFO sSysInfo;

    GetSystemInfo(&sSysInfo);
    return sSysInfo.dwPageSize;
}

http://blog.csdn.net/lostspeed/article/details/8423215