參考文獻:
http://blog.csdn.net/wubin1124/article/details/3760242
工作集(內存): 可以這麼理解, 此值就是該進程所佔用的總物理內存. 但是這個值是由兩部分組成, 即 '專用工作集' + '共享工作集'.
內存(專用工作集): 這對於一個進程是最重要的, 它代表了一個進程獨佔用了多少內存.
內存(共享工作集): 這是該進程和別的進程共享的內存量. 通常, 這是加載一個 dll 所佔用的內存.
提交大小: 屬於 Committed 那一類. 但是不一定在物理內存中, 有些可能位於交換文件中. 如果有一個程序, 原本佔 500MB 內存, 但是絕大多數內存都不使用, 則可以通過 `EmptyWorkingSet` 向操作系統發送請求, 將此進程的不常用的內容從物理內存中換出到換頁文件中保存, 如下圖:
寫在最後
0. 工作集, 即在物理內存中的數據的集合.
1. 工作集 = 專用 + 共享
2. 將所有的 "工作集" 相加後的值會大於任務管理器中內存佔用的百分比, 因爲百分比對共享內存進行排重了.
3. "提交大小" 和 "工作集" 是兩個層面的概念, 大部分活躍進程的 "工作集" 會大於 "提交大小", 而大部分非活躍的進程 "工作集" 會小於 "提交大小", 但是兩者沒有絕對關係.
4. 虛擬內存: 就是換頁文件.
分頁文件:硬盤上一個或者多個隱藏文件pagefile.sys,Windows用於存儲未存入內存的部分程序和數據文件。頁面文件和物理內存或隨機存取內存(RAM)構成了虛擬內存。Windows會根據需要將數據從頁面文件移至內存,或將數據從內存移至頁面文件以便爲新數據釋放內存。也叫“交換文件”。
Sysinternals Suite
// WindbgCmdTest.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include <iostream>
#include <Windows.h>
using namespace std;
#pragma comment(lib,"Psapi.lib")
#include <Psapi.h>
#define MEM_M (1024*1024)
void OutputSystemMem(MEMORYSTATUS New, MEMORYSTATUS Old)
{
//cout<<"減少物理內存="<<(New.dwAvailPhys-Old.dwAvailPhys)/MEM_M<<endl;
//cout<<"減少可用頁文件="<<(New.dwAvailPageFile-Old.dwAvailPageFile)/MEM_M<<endl;
//cout<<"減少可用進程空間="<<(New.dwAvailVirtual-Old.dwAvailVirtual)/MEM_M<<endl;
}
static PROCESS_MEMORY_COUNTERS stLastMem;
void OutputProcessMem()
{
PROCESS_MEMORY_COUNTERS pro;
HANDLE handle = GetCurrentProcess();
GetProcessMemoryInfo(handle, &pro, sizeof(pro));
cout<<"缺頁中斷次數 "<<"new("<<pro.PageFaultCount/MEM_M<<") "<<"old("<<stLastMem.PageFaultCount/MEM_M<<")"<<endl;
cout<<"使用內存高峯 "<<"new("<<pro.PeakWorkingSetSize/MEM_M<<") "<<"old("<<stLastMem.PeakWorkingSetSize/MEM_M<<")"<<endl;
cout<<"當前使用的內存 "<<"new("<<pro.WorkingSetSize/MEM_M<<") "<<"old("<<stLastMem.WorkingSetSize/MEM_M<<")"<<endl;
cout<<"使用頁面緩存池高峯 "<<"new("<<pro.QuotaPeakPagedPoolUsage/MEM_M<<") "<<"old("<<stLastMem.QuotaPeakPagedPoolUsage/MEM_M<<")"<<endl;
cout<<"使用頁面緩存池 "<<"new("<<pro.QuotaPagedPoolUsage/MEM_M<<") "<<"old("<<stLastMem.QuotaPagedPoolUsage/MEM_M<<")"<<endl;
cout<<"使用非分頁緩存池高峯 "<<"new("<<pro.QuotaPeakNonPagedPoolUsage/MEM_M<<") "<<"old("<<stLastMem.QuotaPeakNonPagedPoolUsage/MEM_M<<")"<<endl;
cout<<"使用非分頁緩存池 "<<"new("<<pro.QuotaNonPagedPoolUsage/MEM_M<<") "<<"old("<<stLastMem.QuotaNonPagedPoolUsage/MEM_M<<")"<<endl;
cout<<"使用分頁文件(提交的內存文件大小) "<<"new("<<pro.PagefileUsage/MEM_M<<") "<<"old("<<stLastMem.PagefileUsage/MEM_M<<")"<<endl;
cout<<"使用分頁文件高峯 "<<"new("<<pro.PeakPagefileUsage/MEM_M<<") "<<"old("<<stLastMem.PeakPagefileUsage/MEM_M<<")"<<endl;
cout<<endl;
memcpy(&stLastMem,&pro,sizeof(pro));
}
#define VIRTUAL_ALLOC_TEST_SIZE 10*MEM_M
int _tmain(int argc, _TCHAR* argv[])
{
memset(&stLastMem,0,sizeof(stLastMem));
OutputProcessMem();
MEMORYSTATUS memStatusVirtual;
GlobalMemoryStatus(&memStatusVirtual);
LPVOID pV=VirtualAlloc(NULL,VIRTUAL_ALLOC_TEST_SIZE,MEM_RESERVE|MEM_TOP_DOWN,PAGE_READWRITE);
if(pV==NULL)
{
cout<<"沒有那麼多虛擬空間!"<<endl;
}
MEMORYSTATUS memStatusVirtual1;
GlobalMemoryStatus(&memStatusVirtual1);
cout<<"VirtualAlloc(NULL,1000*1024*1024,MEM_RESERVE|MEM_TOP_DOWN,PAGE_READWRITE);"<<endl;
OutputSystemMem(memStatusVirtual1,memStatusVirtual);
OutputProcessMem();
cout<<"\n";
pV=VirtualAlloc(pV,VIRTUAL_ALLOC_TEST_SIZE,MEM_COMMIT,PAGE_READWRITE);
if (pV == NULL)
{
DWORD eLastError = GetLastError();
cout <<"eLastError: %d" << eLastError;
}
MEMORYSTATUS memStatusVirtual2;
GlobalMemoryStatus(&memStatusVirtual2);
cout<<"VirtualAlloc(pV,10*1024*1024,MEM_COMMIT|MEM_RESERVE,PAGE_READWRITE);"<<endl;
OutputSystemMem(memStatusVirtual2,memStatusVirtual1);
OutputProcessMem();
char * pC = (char *)pV;
cout<<"\n";
cout<<"pC[VIRTUAL_ALLOC_TEST_SIZE-1] = 0;;"<<endl;
pC[VIRTUAL_ALLOC_TEST_SIZE-1] = 0;
OutputProcessMem();
cout<<"\n";
char * p = new char[10*MEM_M];
MEMORYSTATUS memStatusVirtual8;
GlobalMemoryStatus(&memStatusVirtual8);
cout<<"char * p = new char[10*MEM_M];"<<endl;
OutputSystemMem(memStatusVirtual8,memStatusVirtual2);
OutputProcessMem();
cout<<"\n";
VirtualFree(pV,VIRTUAL_ALLOC_TEST_SIZE,MEM_DECOMMIT);
MEMORYSTATUS memStatusVirtual3;
GlobalMemoryStatus(&memStatusVirtual3);
cout<<" VirtualFree(pV,10*1024*1024,MEM_DECOMMIT);"<<endl;
OutputSystemMem(memStatusVirtual3,memStatusVirtual2);
OutputProcessMem();
cout<<"\n";
VirtualFree(pV,VIRTUAL_ALLOC_TEST_SIZE,MEM_RELEASE);
MEMORYSTATUS memStatusVirtual4;
GlobalMemoryStatus(&memStatusVirtual4);
cout<<"VirtualFree(pV,10*1024*1024,MEM_RELEASE);"<<endl;
OutputSystemMem(memStatusVirtual4,memStatusVirtual3);
OutputProcessMem();
cout<<"\n";
VirtualUnlock(pV,VIRTUAL_ALLOC_TEST_SIZE);
MEMORYSTATUS memStatusVirtual5;
GlobalMemoryStatus(&memStatusVirtual5);
cout<<"VirtualUnlock(pV,10*1024*1024);"<<endl;
OutputSystemMem(memStatusVirtual5,memStatusVirtual4);
OutputProcessMem();
cout<<"delete[] p;"<<endl;
delete[] p;
OutputProcessMem();
getchar();
return 0;
}