实验一： 进程的创建与同步.doc

实验一： 进程的创建与同步1实验目的(1) 熟悉Windows系统提供的进程创建与同步。(2) 掌握Windows系统环境下进程的创建与撤销方法。2 进程创建2.1结构体模拟进程PCBtypedef struct pcb int num; struct pcb *next; int priority; int timeneed; int state;pcb;/*用此结构体来模拟一个进程*/2.2 随机产生进程运行的优先级与运行时间srand(unsigned int)time(NULL);for(i=1;inext=q; q-num=i; q-next=NULL; q-priority=1+(10*rand()/(RAND_MAX+1.0);/*随机产生优先级*/ q-timeneed=1+(100*rand()/(RAND_MAX+1.0);/*随机产生运行时间*/ q-state=WAIT; p=q; 3 进程的执行和调度void control()/*此函数是用来控制各个进程的执行和调度*/if(run-timeneed10) /*进程需要时间减少*/run-timeneed=run-timeneed-run-timeneed/10;elserun-timeneed-;run-priority=run-priority-1;/*进程优先级减1*/if(run-prioritynext-priority)/*如果当前运行的进程的优先级低于队首进程的优先级*/run-state=WAIT;run=getmaxpriority(head);/*则从进程队列中挑选一个优先级最大的进程来运行*/run-state=RUN;4 进程删除void delect(struct pcb *head,struct pcb *run)/*此函数用来将运行完成的进程删除出进程队列*/5实验总结6源程序框架#includestdio.h#includestdlib.h#include string.h#include ctime#include #include#define WAIT 1#define RUN 2#define FINISH 3using namespace std;typedef struct pcb int num; struct pcb *next; int priority; int timeneed; int state;pcb;/*用此结构体来模拟一个进程*/struct pcb *head;struct pcb *run;pcb *jccreat(int n)/*此函数用于创建进程队列*/ int i=1; pcb *head,*p,*q; head=(pcb *)malloc(sizeof(pcb);/*创建一个空表头*/ p=head; srand(unsigned int)time(NULL);/ for(i=1;inext=q; q-num=i; q-next=NULL; q-priority=1+(10*rand()/(RAND_MAX+1.0);/*随机产生优先级*/ q-timeneed=1+(100*rand()/(RAND_MAX+1.0);/*随机产生运行时间*/ q-state=WAIT; p=q; return head;/*返回表头指针*/pcb *getmaxpriority(struct pcb *head)/*此函数用来挑选一个优先级最大的进程来执行*/ struct pcb *p,*q; int max; p=head-next; max=p-priority;/*初始max为队首结点的优先级*/ q=p; while(p) if(p-prioritymax)/*逐一比较，选出优先级最大的结点*/ max=p-priority; q=p;/? p=p-next; return q;void delete1(struct pcb *head,struct pcb *run)/*此函数用来将运行完的进程删除出进程队列*/struct pcb *q=head; while(q-next)/*扫描进程队列，找到执行完了的进程*/if(q-next-num=run-num)/*判断是不是已完成的进程*/if(run-next!=NULL)q-next=run-next;else q-next=NULL;free(run);/*释放申请的空间*/return;q=q-next; int i=0;void control()/*此函数是用来控制各个进程的执行和调度*/struct pcb *p;run=head-next;/*初始让第一个进程运行*/run-state=RUN;while(run)if(run-timeneed0)/*如果当前run指针指向的进程所需时间不为零，状态为运行状态，就让这个进程运行*/if(run-state=RUN)printf(pcb %d is running.n,run-num);printf(Waiting list:);/*显示整个等待队列*/p=head-next;while(p)if(p!=run)printf(pcb%d ,p-num);p=p-next;printf(n);Sleep(500);/*模拟进程运行*/if(run-timeneed10)run-timeneed=run-timeneed-run-timeneed/10;/*进程需要时间减少*/elserun-timeneed-;run-priority=run-priority-1;/*进程优先级减1*/couttimeneed;coutt;coutpriority;couttimeneed!=0) if(run!=getmaxpriority(head)/*如果当前运行进程的优先级不等于队列中最大的进程优先级*/ if(run-prioritypriority)/作用不同run-state=WAIT;run=getmaxpriority(head);/*则从进程队列中挑选一个优先级最大的进程来运行*/run-state=RUN;else printf(pcb %d is finished.n,run-num); Sleep(500); delete1(head,run);/*删除该结点*/ if(head-next!=NULL)/*判断进程队列是不是为空*/ run=head-next; run-state=RUN; else printf(All progresses are done.n); return; main()int n;int flag=1;printf(Enter the number of the progresses:);scanf(%d,&n);/*输入要创建的进程的数量*/head=jccreat(n);/*创建进程队列，将链表的表头赋给head指针*/run=head-next;/*run指针指向正在运行的进程的pcb*/while(run)printf(num: %d ,priority: %d ,timeneeds: %d n,run-num,run-priority,run-timeneed); run=run-next; /*将刚创建的进程队列打印出来*/while(flag)/*由fla