1、實驗三 內存管理1一實驗目的1二實驗內容1三實驗設計1四模擬實驗2First.cpp3First.h5Next.cpp7Next.h9五實驗結果12六實驗總結15實驗三 內存管理一實驗目的構造一個沒有虛存功能的內存管理系統，并進行測試和對不同分配策略的性能展開比較評估。本次實驗，選擇的分配策略：First-fit 和 next-fit二實驗內容1、設計一個內存管理器，支持至少兩種分配策略（本實驗使用firstfit策略和nextfit策略）；2、分別對不同的策略進行性能評估三實驗設計1.內存unsigned char mm65536;2. 用戶接口用戶接口函數：int mm_init() /初

2、始化int mm_request(int n) /申請空間void mm_release(int p) /釋放空間3計算請求尺寸srand(unsigned char)time(NULL);tmp = (rand() % 1024) + 1; /最大申請10244.選擇待釋放的塊tmp = (rand() % j);while(ptmp = -1)tmp = rand() % j;requestsize = requestsize - BinToInt(&mmptmp + 4);mm_release(ptmp);cout << "釋放指針 " <&

3、lt; ptmp << endl;ptmp = -1;四模擬實驗實現兩個版本的內存管理器，分配策略分別為：first-fit和next-fitFirst.cpp#include <iostream>#include <stdio.h>#include <windows.h>#include <time.h>#include "first.h"using namespace std;int main()int i;int j = 0; /分配指針數int p1000; /用于存放分配出的指針int tmp;int r

4、equestsize = 0; /統計申請空間int k = 0; /統計搜索步數srand(unsigned char)time(NULL);step = 0;mm_init();for(i = 0; i < 30; i+) /模擬30步cout << "第 " << i + 1 << " 步" << endl;dotmp = (rand() % 1024) + 1; /最大申請1024cout << "申請空間 " << tmp << &qu

5、ot; 字節" << endl;pj = mm_request(tmp);if(pj != -1)requestsize = requestsize+tmp;k = k + step;cout << "分配指針 " << pj << endl;cout << endl;j+;elsecout << "剩余空間不足，分配失敗" << endl;while(pj != -1);tmp = (rand() % j);while(ptmp = -1)tmp = rand

6、() % j;requestsize = requestsize - BinToInt(&mmptmp + 4);mm_release(ptmp);cout << "釋放指針 " << ptmp << endl;ptmp = -1;/以下為性能統計指標cout << endl;cout << "平均申請空間：" << (double)requestsize / (double)j << " 字節" << endl;cout <

7、< "平均空間利用率：" << (double)requestsize/(double)65536 << endl;cout << "平均搜索步數：" << (double)k/(double)j << endl;cout << endl;if(i + 1) % 5 = 0)system("pause");First.hunsigned char mm65536;int step; /記錄搜索步數int BinToInt(unsigned char *s)

8、/把char類型變成intint i;char tmp4;int t;for(i = 0; i < 4; i+)tmp3 - i = si;memcpy(&t,tmp,4);return t;void IntToBin(int s, unsigned char *t) /把int類型變成charint i;char tmp4;memcpy(tmp,&s,4);for(i = 0; i < 4; i+)ti = tmp3 - i;int mm_init()memset(mm, 0, 65536);IntToBin(-1, mm); /前向指針 置-1 放在數組的第一個

9、位置IntToBin(65536, &mm4); /整個塊大小，放在第四個位置IntToBin(-1, &mm65536-4); /后向指針 置-1 放在數組的倒數第四個位置return 0;int mm_request(int n)/四字節前向指針、四字節塊大小、一字節狀態、N字節可用內存、四字節后向指針int pointer = 0;step = 0;while(mmpointer+8=1)|(n+26)>=BinToInt(&mmpointer+4) /pointer+4 表示塊大小/mmpointer+8=1 狀態位是一，說明這一塊已經被分配/n+26 申

10、請的空間+管理開銷pointer=BinToInt(&mmpointer+BinToInt(&mmpointer+4)-4); /找到后向指針if(mmpointer+8 != 1)step+;/非空閑塊不在鏈內，不計步數if(pointer = -1)return -1;mmpointer + 8 = 1; /修改本塊標志位IntToBin(pointer + 4 + 4 + 1 + n + 4, &mmpointer + 9 + n); /修改本塊后向指針IntToBin(pointer, &mmpointer + 4 + 4 + 1 + n + 4); /

11、修改后塊前向指針IntToBin(BinToInt(&mmpointer + 4) - n - 13, &mmpointer + 4 + 4 + 1 + n + 4 + 4); /修改后塊大小IntToBin(n + 13,&mmpointer + 4); /修改本塊大小return pointer;void mm_release(int p)int pre;int bac;pre = BinToInt(&mmp);bac = BinToInt(&mmp + BinToInt(&mmp + 4) - 4);mmp + 8 = 0; /修改本塊標志

12、位if(BinToInt(&mmbac+8) = 0) /如果后塊未使用IntToBin(0,&mmp+BinToInt(&mmp + 4) - 4); /清空本塊后向指針IntToBin(0,&mmbac); /清空后塊前向指針IntToBin(BinToInt(&mmp + 4) + BinToInt(&mmbac + 4), &mmp + 4); /修改本塊大小if(BinToInt(&mmbac + BinToInt(&mmbac + 4) - 4) != -1) /如果后塊不是最后一塊IntToBin(p, &a

13、mp;mmBinToInt(&mmbac + BinToInt(&mmbac + 4) - 4); /修改后塊的后塊前向指針IntToBin(0, &mmbac + 4); /清空后塊大小if(pre = -1)return;if(BinToInt(&mmpre + 8) = 0) /如果前塊未使用IntToBin(0, &mmpre + BinToInt(&mmpre + 4) - 4); /清空前塊后向指針IntToBin(BinToInt(&mmpre + 4) + BinToInt(&mmp + 4), &mmpr

14、e + 4); /修改前塊大小IntToBin(pre, &mmBinToInt(&mmp + BinToInt(&mmp + 4) - 4); /修改后塊前向指針IntToBin(0, &mmp + 4); /清空本塊大小IntToBin(0, &mmp); /清空本塊前向指針Next.cpp#include <iostream>#include <stdio.h>#include <windows.h>#include <time.h>#include "next.h"using n

15、amespace std;int main()int i;int j = 0; /分配指針數int p1000; /用于存放分配出的指針int tmp;int requestsize = 0; /統計申請空間int k = 0; /統計搜索步數srand(unsigned char)time(NULL);step = 0;next = 0;end = -1;mm_init();for(i = 0; i < 30; i+)/模擬30步cout << "這是第 " << i + 1 << " 步" <<

16、endl;dotmp = (rand() % 1024) + 1; /最大申請1024cout << "申請空間 " << tmp << " 字節" << endl;pj = mm_request(tmp);if(pj != -1)requestsize = requestsize + tmp;k = k + step;cout << "分配指針：" << pj << endl;cout << endl;j+;elsecout <&l

17、t; "剩余空間不足，分配失敗。" << endl;while(pj != -1);tmp = (rand() % j);while(ptmp = -1)tmp = rand() % j;requestsize = requestsize - BinToInt(&mmptmp + 4);mm_release(ptmp);cout << "釋放指針：" << ptmp << endl;ptmp = -1;/以下為性能統計指標cout << endl;cout << "

18、平均申請空間：" << (double)requestsize/(double)j << " 字節" << endl;cout << "平均空間利用率：" << (double)requestsize/(double)65536 << endl;cout << "平均搜索步數：" << (double)k/(double)j << endl;cout << endl;if(i + 1) % 5 = 0)sy

19、stem("pause");Next.hunsigned char mm65536;int step;int next;int end;int BinToInt(unsigned char *s)int i;char tmp4;int t;for(i = 0; i < 4; i+)tmp3 - i = si;memcpy(&t,tmp,4);return t;void IntToBin(int s, unsigned char *t)int i;char tmp4;memcpy(tmp,&s,4);for(i = 0; i < 4; i+)ti

20、= tmp3 - i;int mm_init()memset(mm, 0, 65536);IntToBin(-1, mm);IntToBin(65536, &mm4);IntToBin(-1, &mm65536-4);return 0;int mm_request(int n)/四字節前向指針、四字節塊大小、一字節狀態、N字節可用內存、四字節后向指針int pointer;step = 0;pointer = next;while(pointer != -1)if(mmpointer + 8 != 1) && (n + 26) < BinToInt(&am

21、p;mmpointer + 4)break;pointer = BinToInt(&mmpointer + BinToInt(&mmpointer + 4) - 4);/step+;if(mmpointer + 8 != 1)step+;if(pointer = -1)pointer = 0;while(pointer != end)if(mmpointer + 8 != 1) && (n + 26) < BinToInt(&mmpointer + 4)break;pointer = BinToInt(&mmpointer + BinToI

22、nt(&mmpointer + 4) - 4);if(mmpointer + 8 != 1)step+;/step+;if(pointer = end)return -1;mmpointer+8 = 1; /修改本塊標志位IntToBin(pointer + 4 + 4 + 1 + n + 4, &mmpointer + 9 + n); /修改本塊后向指針IntToBin(pointer, &mmpointer + 4 + 4 + 1 + n + 4); /修改后塊前向指針IntToBin(BinToInt(&mmpointer + 4) - n - 13, &

23、amp;mmpointer + 4 + 4 + 1 + n + 4 + 4); /修改后塊大小IntToBin(n + 13, &mmpointer + 4); /修改本塊大小end = pointer;next = pointer + 4 + 4 + 1 + n + 4;return pointer;void mm_release(int p)int pre;int bac;pre = BinToInt(&mmp);bac = BinToInt(&mmp + BinToInt(&mmp + 4) - 4);mmp + 8 = 0; /修改本塊標志位if(Bin

24、ToInt(&mmbac + 8) = 0) /如果后塊未使用IntToBin(0, &mmp + BinToInt(&mmp + 4) - 4); /清空本塊后向指針IntToBin(0, &mmbac); /清空后塊前向指針IntToBin(BinToInt(&mmp + 4) + BinToInt(&mmbac + 4), &mmp + 4); /修改本塊大小if(BinToInt(&mmbac + BinToInt(&mmbac + 4) - 4) != -1) /如果后塊不是最后一塊IntToBin(p, &am

25、p;mmBinToInt(&mmbac + BinToInt(&mmbac + 4) - 4); /修改后塊的后塊前向指針IntToBin(0, &mmbac + 4); /清空后塊大小if(pre = -1)return;if(BinToInt(&mmpre + 8) = 0) /如果前塊未使用IntToBin(0, &mmpre + BinToInt(&mmpre + 4) - 4); /清空前塊后向指針IntToBin(0, &mmp); /清空本塊前向指針IntToBin(BinToInt(&mmpre + 4) + BinToInt(&mmp + 4), &mmpre + 4); /修改前塊大小IntToBin(pre, &mmBinToInt(&mmp + BinToInt(&mmp + 4) - 4); /修改后塊前向指針IntToBin(0, &mmp + 4); /清空本塊大小五實驗結果1 .實現的兩種分配策略：first-fit 和 next-fit2. 設計測試程序，收集實驗數據：First-