电路设计

进程状态转换及其PCB的变化

2019-07-14 06:43发布

站内文章 / 电路设计
10802 0 925
代码实现了模拟进程状态转换及其相应PCB内容、组织结构的变化。 #include using namespace std; typedef struct pcb{ int id; struct pcb *next; }pcb; pcb *ready,*run,*block; pcb* cre()//创建带头结点的ready队列 { pcb *head=new pcb; head->next=NULL; pcb *q=head; int n; cout<<"输入进程数: "; cin>>n; for(int i=0;i>p->id; p->next=NULL; q->next=p; q=p; } return head; } void ins(pcb *head,pcb *node)//插入节点 { pcb *p=head; while(p->next) { p=p->next; } pcb *n=new pcb; n->id=node->id; p->next=n; n->next=NULL; } void del(pcb *head) { pcb *p=head->next; if(p) { head->next=head->next->next; delete p; } } void dis() { pcb *p; p=ready->next; cout<<"ready: "; while(p) { cout<id<<" "; p=p->next; } cout<next; cout<<"run : "; while(p) { cout<id<<" "; p=p->next; } cout<next; cout<<"block: "; while(p) { cout<id<<" "; p=p->next; } cout<next=NULL; block=new pcb; block->next=NULL; dis(); int i; cout<<"chose: 1:ready->run 2:run->ready 3:run->block 4:block->ready "; while(cin>>i) { if(i==1) { if(ready->next) { if(run->next) { ins(block,run->next); del(run); } ins(run,ready->next); del(ready); } else { if(block->next) { ins(block,run->next); del(run); ins(run,block->next); del(block); } } } else if(i==2) { if(run->next) { if(ready->next) { ins(ready,run->next); del(run); ins(run,ready->next); del(ready); } } } else if(i==3) { if(run->next) { if(ready->next) { ins(block,run->next); ins(run,ready->next); del(run); del(ready); } else { ins(block,run->next); ins(run,block->next); del(block); del(run); } } } else if(i==4) { if(block->next) { ins(ready,block->next); del(block); } } else break; dis(); cout<<"chose: 1:ready->run 2:run->ready 3:run->block 4:block->ready "; } return 0; }


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