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.cpp . 2First.h . 4Next.cpp . 6Next.h . 8五實驗結果 . 11六實驗總結 . 13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unsigned char mm65536;用

2、戶接口函數：int mm_init() /初始化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1024tmp = (rand() % j);while(ptmp = -1)requestsize = requestsize - BinToInt(&mmptmp + 4);mm_release(ptmp);tmp = rand() % j; cout << "釋放指

3、針 " << ptmp << endl;ptmp = -1;四模擬實驗#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 requestsize = 0; /統計申請空間int k = 0;

4、/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 /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 << "平均空間利用率：" << (double)requestsize/

5、(double)65536 << endl; tmp = (rand() % j); while(ptmp = -1) requestsize = requestsize - BinToInt(&mmptmp + 4); mm_release(ptmp); cout << "釋放指針 " << ptmp << endl; ptmp = -1; tmp = rand() % j; while(pj != -1); else cout << "剩余空間不足，分配失敗" << en

6、dl; cout << "分配指針 " << pj << endl; cout << endl; j+; pj = mm_request(tmp); if(pj != -1) requestsize = requestsize+tmp; k = k + step; cout << "申請空間 " << tmp << " 字節" << endl; cout << "第 " << i + 1 <

7、< " 步" << endl; do tmp = (rand() % 1024) + 1; /最大申請1024 cout << "平均搜索步數：" << (double)k/(double)j << endl; cout << endl; if(i + 1) % 5 = 0) system("pause");unsigned char mm65536;int step; /記錄搜索步數int BinToInt(unsigned char *s) /把char類型變成in

8、tint 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 放在數組的第一個位置IntToBin

9、(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; /修改本塊標志位IntToBin(pointer

10、+ 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, &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

11、pre;int bac;pre = BinToInt(&mmp);bac = BinToInt(&mmp + BinToInt(&mmp + 4) - 4);mmp + 8 = 0; /修改本塊標志位if(BinToInt(&mmbac+8) = 0) /如果后塊未使用if(pre = -1) 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(

12、&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(0, &mmbac + 4); /清空后塊大小 IntToBin(p, &mmBinToInt(&mmbac + BinToInt(&mmbac + 4) - 4); /修改后塊的/mmpointer+8=1 狀態位是一，說明這一塊已經被分配 /n+26 申請的空間+管理開銷 pointer=BinToInt(&

13、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; 后塊前向指針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), &mm

14、pre + 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 return;#include <iostream>#include <stdio.h>#include <windows.h>#include <time.h>#include "next.h"us

15、ing 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 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;do while(pj != -1); tmp = (rand() % j); while(ptmp = -1) 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)reques

17、tsize/(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; tmp = rand() % j; tmp = (rand() % 1024) + 1; /最大申請102

18、4 cout << "申請空間 " << tmp << " 字節" << endl; pj = mm_request(tmp); if(pj != -1) else cout << "剩余空間不足，分配失敗。" << endl; requestsize = requestsize + tmp; k = k + step; cout << "分配指針：" << pj << endl; cout <<

19、 endl; j+;if(i + 1) % 5 = 0) system("pause");unsigned 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+)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 &

20、lt; 4; i+) ti = tmp3 - i; tmp3 - i = si;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(pointer = -1)while(pointer

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

22、mmpointer + BinToInt(&mmpointer + 4) - 4); /step+; if(mmpointer + 8 != 1) step+; break; step+; /step+;if(pointer = end)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(BinToIn

23、t(&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)

24、 - 4);mmp + 8 = 0; /修改本塊標志位if(BinToInt(&mmbac + 8) = 0) /如果后塊未使用if(pre = -1)return; if(BinToInt(&mmbac + BinToInt(&mmbac + 4) - 4) != -1) /如果后塊不是最后一塊 IntToBin(0, &mmbac + 4); /清空后塊大小 IntToBin(p, &mmBinToInt(&mmbac + BinToInt(&mmbac + 4) - 4); /修改后塊的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 return -1; 后塊前向指針if(BinToInt(&mmpre + 8) = 0) /如果前塊未使用 IntToBin(0, &mmpre + BinToInt(&mmpre +