操作系统内存管理代码.doc

程序代码：#include#include#define MAXMSIZE 99using namespace std;struct Nodeint startAddress;char name;int size;int endAddress;struct Node *prior;struct Node *next;struct Blocklist Node* head;Blocklist* freelist=new Blocklist;Blocklist* busylist=new Blocklist;void initial();void allocateBlock();void print();void reclaimBlock();void main()int slct; initial();print(); coutselect allocetion (1) or reclaim (2):slct;switch( slct )case 1: allocateBlock(); print(); break;case 2: reclaimBlock();print(); break;default: break;void allocateBlock() /分配分区char nm;int strtadd,sz; Node *ftemp,*delt,*btemp;ftemp=freelist-head ;btemp=busylist-head ;coutplseae input a new block information: endl;cout -name-startAdd-size- nmstrtaddsz;bool bfinish=false;bool ffinish=false;Node* p=new Node;p-name =nm;p-startAddress =strtadd;p-size =sz;p-endAddress =p-startAddress +p-size-1 ;if( busylist-head =NULL & bfinish =false) /分配使用链表的头结点btemp =p;btemp-prior =NULL;btemp-next =NULL;bfinish =true;busylist-head =btemp;elsewhile( btemp !=NULL & bfinish=false) /查找使用链表的可分配点if( btemp-endAddress startAddress & btemp-next =NULL) /加入使用链表链尾p-next =NULL;p-prior =btemp;btemp-next =p;bfinish =true;else if(btemp-endAddress startAddress & btemp-next-startAddress p-endAddress ) /加入使用链表链中p-next = btemp-next ; p-prior =btemp; btemp-next-prior =p;btemp-next =p;bfinish =true; else if( btemp-prior =NULL & btemp-startAddress p-endAddress & p-startAddress =0) /加入使用链表链头p-next =btemp;p-prior =NULL;btemp-prior =p;busylist-head =p;bfinish =true;btemp=btemp-next ; while( ftemp!=NULL & ffinish=false & bfinish =true ) /增加结点修改空闲链表 if( ftemp-startAddress startAddress & ftemp-endAddress =p-endAddress )Node* q=new Node;q-startAddress =p-endAddress +1;q-endAddress =ftemp-endAddress;q-size =q-endAddress- q-startAddress +1;q-prior =ftemp;q-next =ftemp-next ; ftemp-endAddress =p-startAddress-1;ftemp-size =ftemp-endAddress -ftemp-startAddress +1 ;ftemp-next =q ;ffinish =true;ftemp= ftemp-next; if( ffinish=true) /查找需要删除的结点并删除之 ftemp =freelist-head ; while( ftemp!=NULL) if( ftemp-size=0) if( ftemp = freelist-head ) freelist-head =ftemp-next ; else ftemp-prior -next =ftemp-next ; ftemp-next -prior =ftemp-prior ; delt =ftemp; ftemp =ftemp-next ; delete delt; else ftemp =ftemp-next ;coutit has been allocated !endl;elsecoutit cannot allocate!endl;void initial() /初始分配coutinitial. startAddress =0;fl-endAddress =MAXMSIZE;fl-size =fl-endAddress-fl-startAddress+1 ;fl-prior =NULL;fl-next =NULL;freelist-head =fl; busylist-head =NULL;void print() /打印执行结果Node* ftemp=freelist-head;Node* btemp=busylist-head ;coutfreelist information-startadd-endadd-size-endl;while( ftemp!=NULL )cout -startAddress - endAddress -size next ;coutbusylist information-name-startadd-endadd-size-endl;while( btemp!=NULL )cout -name -startAddress -endAddress-size next ; couthead ;btemp=busylist-head ;coutplease input the name of reclaimed block:nm; while( btemp!=NULL) / 确定要回收的内存空间if( btemp-name=nm) break;btemp =btemp-next; while( ftemp!=NULL) / 回收选定的内存空间 if( btemp-endAddress head-startAddress ) / 要回收的内存在空闲链表之前if( ftemp-startAddress = btemp-endAddress+1)ftemp-startAddress = btemp-startAddress ;ftemp-size +=btemp-size ;ftemp-prior =NULL;else busylist-head =btemp-next ;if(busylist-head) busylist-head -prior =NULL; btemp-next =freelist-head ; btemp-prior =NULL; freelist-head -prior =btemp; freelist-head =btemp; freelist-head -prior =NULL; finish =true;else if( btemp-startAddress ftemp-endAddress & btemp-endAddress next -startAddress ) /要回收的内存在空闲链表之中if( btemp-startAddress =ftemp-endAddress +1 & btemp-endAddress =ftemp-next-startAddress -1)/上下皆邻ftemp-size = ftemp-size +btemp-size +ftemp-next-size;ftemp-endAddress =ftemp-startAddress +ftemp-size -1;if ( ftemp-next -next)ftemp-next-next-prior =ftemp;ftemp-next = ftemp-next -next ;else if(btemp-startAddress =ftemp-endAddress +1) /上邻 ftemp-size +=btemp-size ;ftemp-endAddress =ftemp-startAddress +ftemp-size -1; else if(btemp-endAddress =ftemp-next-startAddress -1) /下邻ftemp-next-startAddress =btemp-startAddress ;ftemp-size =ftemp-next -endAddress -ftemp-next -startAddress +1;else /上下都不相邻btemp-next =ftemp-next ;ftemp-next -prior =btemp;ftemp-next =btemp;btemp-prior =ftemp;ftemp=ftemp-next ; if( !btemp-prior & finish=false )busylist-head =btemp-next ; if(busylist-head)busylist-head -prior =NULL;else if( finish=false)if( btemp-next )btemp-next -prior =btemp-prior;btemp-prior-next =btemp-next ;运行结果：initial.freelist information-startadd-endadd-size- -0 - 99-100busylist information-name-startadd-endadd-size-select allocetion (1) or reclaim (2):1plseae input a new block information: -name-startAdd-size-a 20 25it has been allocated !freelist information-startadd-endadd-size- -0 - 19-20 -45 - 99-55busylist information-name-startadd-endadd-size- -a-20-44-251plseae input a new block information: -name-startAdd-size-b 48 20it has been allocated !freelist information-startadd-endadd-size- -0 - 19-20 -45 - 47-3 -68 - 99-32busylist information-name-startadd-endadd-size- -a-20-44-25 -b-48-67-201plseae input a new block information: -name-startAdd-size-c 70 10it has been allocated !freelist information-startadd-endadd-size- -0 - 19-20 -45 - 47-3 -68 - 69-2 -80 - 99-20bus