銀行家算法源程序

1、銀行家算法源程序#include#include #include using namespace std;#define false 0#define true !false#define jcsl 5/系統(tǒng)中所有進程數(shù)量typedef struct int a;int b;int c;jc;jc maxjcsl=7,5,3,3,2,2,9,0,2,2,2,2,4,3,3;/ 最大需求矩陣jc allocationjcsl=0,1,0,2,0,0,3,0,2,2,1,1,0,0,2;/已分配資源數(shù)矩陣 jc needjcsl=7,4,3,1,2,2,6,0,0,0,1,1,4,3,1;/ 需

2、求矩陣jc available=3,3,2;/可用資源向量int safejcsl;void probealloc(int process,jc *res)/試探分配available.a-=res-a;available.b-=res-b;available.c-=res-c;allocationprocess.a+=res-a;allocationprocess.b+=res-b;allocationprocess.c+=res-c;needprocess.a-=res-a;needprocess.b-=res-b;needprocess.c-=res-c;void rollback(in

3、t process,jc *res)/若試探分配后進入不安全狀態(tài)，將分配回滾 available.a+=res-a;available.b+=res-b;available.c+=res-c;allocationprocess.a-=res-a;allocationprocess.b-=res-b;allocationprocess.c-=res-c;needprocess.a+=res-a;needprocess.b+=res-b;needprocess.c+=res-c;/安全性檢查bool safecheck()jc work=available;bool finishjcsl=fals

4、e,false,false,false,false;int i;int j=0;for(i=0;ijcsl;i+)if(finishi=false)/是否已檢查過if(needi.a=work.a & needi.b=work.b & needi.c=work.c) / 是否有足夠的資源分配給該進程/有則使其執(zhí)行完成，并將已分配給該進程的資源全部回收 work.a+=allocationi.a;work.b+=allocationi.b;work.c+=allocationi.c;finishi=true;safej+=i;i=-1; /重新進行遍歷for (i=0;iabcabc=avail

5、able.c) /request 向量需小于 available 向量probealloc(process,res);/試探分配if(safecheck()/如果安全檢查成立，則請求成功，否則將分配回滾并返回失 敗return true;elsecout安全性檢查失敗。原因：系統(tǒng)將進入不安全狀態(tài)，有可能引起死鎖.endl;rollback(process,res);elsecout安全性檢查失敗。原因：請求向量大于可利用資源向量。endl; elsecout安全性檢查失敗。原因：請求向量大于需求向量。endl;return false;/輸出資源分配表void printtable()cout

6、ttt*資源分配表*endl;coutprocess max allocation need availa bleendl;cout a b c a b c a b ca b cendl;printf( p0 %d %d %d %d %d %d %d %d %d %d %d %dn,max0.a,max0.b,max0.c,allocation0.a,allocation0.b,allocation0.c,need0.a,need0.b,need0.c,available.a,available.b,available.c);printf( p1 %d %d %d %d %d %d %d %d

7、 %dn,max1.a,max1.b,max1.c,allocation1.a,allocation1.b,allocation1.c,need1.a,need1.b,need1.c);printf( p2 %d %d %d %d %d %d %d %d %dn,max2.a,max2.b,max2.c,allocation2.a,allocation2.b,allocation2.c,need2.a,need2.b,need2.c);printf( p3 %d %d %d %d %d %d %d %d %dn,max3.a,max3.b,max3.c,allocation3.a,alloca

8、tion3.b,allocation3.c,need3.a,need3.b,need3.c);printf( p4 %d %d %d %d %d %d %d %d %dn,max4.a,max4.b,max4.c,allocation4.a,allocation4.b,allocation4.c,need4.a,need4.b,need4.c);coutendl;int main()int ch;cout先檢查初始狀態(tài)是否安全.endl;if (safecheck()cout系統(tǒng)處于安全狀態(tài)。endl;printf(安全序列是p%d,p%d,p%d,p%d,p%d 。n,safe0,safe1,safe2,safe3,safe4);elsecout系統(tǒng)處于不安全狀態(tài)。程序?qū)⑼顺?endl;return 0;doint process;jc res;printtable();coutprocessres.ares.bres.c;if (request(process,&res)cout分配成功。endl;printf(安全序列是p%d,p%d,p%d,p%d,p%d 。n,safe0,safe1,safe2,safe3,safe4