计算机操作系统 内存动态分配和回收模拟实现.doc

计算机操作系统 内存动态分配和回收模拟实现计算机操作系统 内存动态分配和回收模拟实现.txt一个人一盒烟一台电脑过一天一个人一瓶酒一盘蚕豆过一宿。永远扛不住女人的小脾气，女人永远抵不住男人的花言巧语。/COPYRIGHT 2010 tragedy ring finger. ALL RIGHTS RESERVED.#include #include using namespace std;/空闲分区20个，已分配分区20个struct empty/空闲分区表int address_of_start; /起始地址int size_of_empty; /空闲大小int next;int yesorno; /是否空闲,1 空闲，有效 Empty20;struct not_empty/已分配分区表int pid;int address_of_start;int size_of_notempty;int next;int yesorno; /是否分配，1 分配 有效 Not_Empty20;int CountOfEmpty=1,CountOfNotEmpty=0; /从 0 开始计数int Min_Size = 2; /不可分割的最小分区int Max_Size = 300; /最大空间300 X 300 = 90000int Num_Of_Row = 30; /显示时，横排个数int Num_Of_Area = 20; /空闲分区 和 分配分区 的最大分区数int enough(int Size_Of_NotEmpty) /是否有足够的空闲空间int i;for (i=0;i= Size_Of_NotEmpty + Min_Size)return i;return -1;int where(int num ,int a) /找到起始地址为num的区域的下标，a0 = -1，则在Not_Empty中，下标为a1；a1 = -1 在Empty中，下标为a0int i=0;while (i Num_Of_Area)if (Emptyi.address_of_start = num & Emptyi.yesorno = 1)a0 = i;a1 = -1;return 0;if (Not_Emptyi.address_of_start = num & Not_Emptyi.yesorno = 1)a0 = -1;a1 = i;return 0;i += 1;return -1;int fenpei()int temp,i;CountOfNotEmpty += 1;Not_EmptyCountOfNotEmpty.yesorno = 0;for (i=0;iCountOfNotEmpty;i+)if (Not_Emptyi.yesorno = 0)cout输入进程ID (0 99),占用空间大小(0 Max_SizeNot_Emptyi.pidNot_Emptyi.size_of_notempty;if (Not_Emptyi.pid 99)CountOfNotEmpty -= 1;cout进程号 0 99n;return -1;for (int ii=0;iiCountOfNotEmpty;ii+)if (Not_Emptyi.pid = Not_Emptyii.pid & i!= ii)CountOfNotEmpty -= 1;cout= 0) /找到能满足请求的空闲分区Not_Emptyi.address_of_start = Emptytemp.address_of_start;Not_Emptyi.yesorno = 1;Emptytemp.address_of_start += Not_Emptyi.size_of_notempty;Emptytemp.size_of_empty -= Not_Emptyi.size_of_notempty;else CountOfNotEmpty -= 1;cout未找到足够大的空闲分区n;return -1;return 0;int front(int i,int& a) /i 为待回收区在 Not_Empty 中的下标。a存对应下标for (int ii=0;iiCountOfEmpty;ii+) /确定待回收区前一个分区是否是空闲分区，及返回空闲分区的下标if (Not_Emptyi.address_of_start = Emptyii.address_of_start + Emptyii.size_of_empty& Emptyii.yesorno = 1)a = ii;return 0;a = i; /如果前一分区不是空闲，则前一分区是已分配，或待回收区是第一个分区。return -1;int back(int i,int& a) /i 为待回收区在 Not_Empty 中的下标。a存对应下标for (int ii= 0;iiCountOfEmpty;ii+)if (Emptyii.address_of_start = Not_Emptyi.address_of_start + Not_Emptyi.size_of_notempty & Emptyii.yesorno = 1)a = ii;return 0;a = i;return -1;void swap(int i ,int j,int sign)if (sign = 0)empty temp;temp = Emptyi;Emptyi = Emptyj;Emptyj = temp;elsenot_empty temp;temp = Not_Emptyi;Not_Emptyi =Not_Emptyj;Not_Emptyj = temp;void decrease_CountOfEmpty()int i;for (i=0;iCountOfEmpty;i+)if (Emptyi.yesorno = 0)swap(i,CountOfEmpty-1,0);CountOfEmpty -= 1;break;void decrease_CountOfNotEmpty()int i;for (i=0;iCountOfNotEmpty;i+)if (Not_Emptyi.yesorno = 0)swap(i,CountOfNotEmpty-1,1);CountOfNotEmpty -= 1;break;int huishou()int pid,i,a,b;cout输入要回收的进程号pid;for (i=0;iCountOfNotEmpty;i+)if (Not_Emptyi.pid = pid)if (front(i,a) = 0) /待回收分区前面是空闲分区Emptya.size_of_empty += Not_Emptyi.size_of_notempty;Not_Emptyi.yesorno = 0;if (back(i,b) = 0) /待回收区后面是空闲分区Emptya.size_of_empty += Emptyb.size_of_empty;Emptyb.yesorno = 0;/空满空 回收之后 空 decrease_CountOfNotEmpty();decrease_CountOfEmpty();else /待回收分区后面没分区,或后面是已分配分区/空满 回收之后 空/空满满 回收之后 空满decrease_CountOfNotEmpty();else /待回收分区前面没分区,或前面是已分配分区if (back(i,b) = 0) /待回收区后面是空闲分区Emptyb.address_of_start = Not_Emptyi.address_of_start;Emptyb.size_of_empty += Not_Emptyi.size_of_notempty;Emptyb.yesorno = 1;Not_Emptyi.yesorno = 0;/满满空 回收之后 满空/满空 回收之后 空decrease_CountOfNotEmpty();else /待回收分区后面没分区,或后面是已分配分区a = -1;for (int ii=0;iiCountOfEmpty;ii+) /if (Emptyii.yesorno = 0) /找一个没用的空闲分区表，将下表分给a，如果都有用，就扩大空闲分区表的大小a = ii;break;if (a = -1)CountOfEmpty += 1; /找一个没用的空闲分区表，将下表分给a，如果都有用，就扩大空闲分区表的大小a = CountOfEmpty - 1; /Emptya.address_of_start = Not_Emptyi.address_of_start;Emptya.size_of_empty = Not_Emptyi.size_of_notempty;Emptya.yesorno = 1;Not_Emptyi.yesorno = 0;/满满满空/满 回收之后 空/满满满满空满/ 满满空满decrease_CountOfNotEmpty();/CountOfNotEmpty -= 1;回收之后让已分配分区数减一，但是没考虑到对应情况会使空闲和分配区数量变或不变return 0;void qsort_empty_address_of_start(empty a,int low,int high)int i = low,j = high;empty temp=alow;while(ij)while(ij & temp.address_of_start= aj.address_of_start) j-;if(ij)ai = aj;i+;while (ij & ai.address_of_start temp.address_of_start) i+;if(ij)aj = ai;j-;ai = temp;if(lowi) qsort_empty_address_of_start(a,low,i-1);if(ihigh) qsort_empty_address_of_start(a,j+1,high);void show()int a2,num = 0,i,count = 0,times=0;coutn* Memory State *nendl;while (count a1)for (i=0;iEmptya0.size_of_empty;i+)cout;count += 1;if (count)% Num_Of_Row = 0)coutendl;num += Emptya0.size_of_empty;elsecoutsetw(2)Not_Emptya1.pid;count += 1;if (count)% Num_Of_Row = 0)coutendl;for (i=1;iNot_Emptya1.size_of_notempty;i+)cout;count += 1;if (count)% Num_Of_Row = 0)coutendl;num += Not_Emptya1.size_of_notempty;times += 1;coutendl;void show_empty()int i;coutn空闲分区列表n;for (i=0;iCountOfEmpty;i+)if (Emptyi.yesorno = 1)coutEmptyi.address_of_start Emptyi.size_of_emptyendl;int main()Empty0.address_of_start = 0;Empty0.size_of_empty = Max_Size ;Empty0.yesorno = 1;int i;cout*Memory Size: Max_Size *nendl;couti)switch(i)case 1:if (fen