进程同步模拟实验

1、 1 2022-3-24进程调度及进程同步模拟实验要求编程完成进程调度及同步模拟。可定义若干进程并发执行，进程数可定义以上进程。进程同步与互斥问题可选n用生产者消费者问题n哲学家就餐问题n读者写者问题l进程调度可任选一种调度算法l每进程完成的工作最好写在磁盘文件中。进程调度及进程同步模拟实验l下列程序是完成进程同步与互斥的信号量操作，有三个进程pcb1.3共享变量s1,s2，三进程s1作加运算，pcb2,pcb3对s2作加运算。主要数据结构进程控制块structint id; /*进程标识*/char status /*进程状态*/;int nextwr; /*指向进程控制块后继的指针*/in

2、t priority; /*进程优先级*/ pcb3; /*进程控制块*/struct int value; int firstwr; /指向信号量等待队列 sem2;/信号量主要数据结构lchar savearea34；/上下文切换区，存放三个进程在切换时的上下文lchar addr;/地址变量lint i,s1,s2,seed,exe=NIL;/s1,s2是共享变量寄存器i地址主要模块l初始化模块init() /初始化程序l int j;l for (j=0;j3;j+)l pcbj.id=j;l pcbj.status=r;/进程控制块初始化，进程状态是就绪态l pcbj.nextwr=

3、NIL;l printf(n process %d priority? ,j+1);l scanf(%d,&i);l pcbj.priority=i;l l sem0.value=1; /信号量初始化l sem0.firstwr=NIL;l sem1.value=1;l sem1.firstwr=NIL;l for(i=0;i3;i+)l for(j=0;j4;j+)l saveareaij=0;/上下文切换区初始化为空l主要模块lfloat random()lint m;l if(seed0) m=-seed;l else m=seed;l seed=(25173*seed+1384

4、9)%65535;l return(m/32767.0);l/产生随机数程序主要模块ltimeint(char ad) /* The time slice interrupt*/l /子调度程序l float x;l x=random();l if(x0.33 & exe=0) return(FALSE);l if(x0.66 & exe=1) return(FALSE);l if(x1 & exe=2) return(FALSE);l saveareaexe0=i;/用变量I模仿寄存器，作为保存上下文内容之一。l saveareaexe1=ad;/被调度程序的地址l

5、pcbexe.status=t;/进程状态为高就绪态l printf(Times silce interrupt process%d enter into ready.n,exe+1);l exe=NIL; exe指向正在执行（运行）的进程l return TRUE;llscheduler()进程调度程序lint pd;l if(pd=find()=NIL & exe=NIL)l return(NIL);/此时无进程可调度，系统为空闲l if(pd!=NIL)l if(exe=NIL)l pcbpd.status=e;l exe=pd;l printf(process%d is exe

6、cuting.n,exe+1);l l else if(pcbpd.prioritypcbexe.priority)l pcbexe.status=r;l printf(process %d enter into readyn,exe+1);l pcbpd.status=e;l exe=pd;l printf(process %d is executingn,exe+1);l l l i=saveareaexe0;l addr=saveareaexe1;l return(exe);l1.find()先查找高就绪态进程队列中找一进程，若没有低再到就绪态进程队列中找一进程。2. int j,pd=

7、NIL,w=MAXPRI;3. for(j=0;j3;j+)4. if(pcbj.status=r)5. if(pcbj.priorityw)6. w=pcbj.priority;7.pd=j;8. 9. if(pd=NIL)10. for(j=0;j3;j+)11. if(pcbj.status=t)12.if(pcbj.priority=0) return(FALSE);4. block(se);5. saveareaexe0=i;6. saveareaexe1=ad;7. exe=NIL;8. return(TRUE);9.进程阻塞操作lblock(se)lint se;lint w;l

8、printf(process %d is blockedn,exe+1);lpcbexe.status=w;lpcbexe.nextwr=NIL;lif(w=semse.firstwr)=NIL)lsemse.firstwr=exe;lelsel while(pcbw.nextwr!=NIL)lw=pcbw.nextwr;l pcbw.nextwr=exe;l l信号量的signal()操作1.signal(int se,char ad)2. if(+semse.value0) return(FALSE);3. wakeup(se);4. saveareaexe1=ad;5. savearea

9、exe0=i;6. return(TRUE);7.进程唤醒操作1.wakeup(int se)2. int w;3. w=semse.firstwr;4. if(w!=NIL)5. semse.firstwr=pcbw.nextwr;6. pcbw.status=r;7. printf(process %d is waken upn,w+1);8. 9.process1() if(addr=a) goto a1; if(addr=b) goto b1; if(addr=c) goto c1; if(addr=d) goto d1; if(addr=e) goto e1; if(addr=f)

10、goto f1; Process()。for(i=1;i6;i+) printf(process1 calls wait on the semaphore 1n); if(wait(0,a) break;a1: printf(process1 is call wait on the semphore 1n); if(timeint(b) break;b1: printf(“s1=%dn”,+s1); printf(process1 call signal on semphore1 and quit cretical section 1.n); if(signal(0,c) break;c1:

11、printf(process1 call wait on semphore 2.n); if(wait(1,d) break;d1: printf(process1 is execting cretical section 2.n); if(timeint(e) break;e1: printf(“s2=%dn”,+s2); printf(process1 call signal on semaphore2 and quit cretical section2n); if(signal(1,f) break;f1: printf(process1 cycle count =%dn,i); if

12、(i6) return ; eexit(0);Process()。 for(i=1;i6;i+) printf(process2 calls wait on the semaphore 2.n); if(wait(1,a) break;a2: printf(process2 is call wait on the semphore 2.n); if(timeint(b) break;b2: printf(“s2=%dn”,+s2); printf(process2 call signal on semphore1 and quit cretical section 2.n); if(signa

13、l(1,c) break;c2: printf(process2 call wait on semphore 1.n); if(wait(0,d) break;d2: printf(process2 is execting cretical section 1.n); if(timeint(e) break;e2: printf(“s1=%dn”,+s1); printf(process2 call signal on semaphore2 and quit cretical section1n); if(signal(0,f) break;f2: printf(process2 cycle

14、count =%dn,i); if(i6) return ; eexit(0);process3() if(addr=a) goto a3; if(addr=b) goto b3; if(addr=c) goto c3; for(i=1;i6;i+) printf(process3 calls wait on the semaphore 2.n); if(wait(1,a) break;a3: printf(process3 is execting cretical section 2.n); if(timeint(b) break;b3: printf(s2=%dn,+s2); printf(process3 call signal on semphore2 and quit cretical section 2.n); if(signal(1,c) break;c3: printf(process3 cycle count =%dn,i); if(i6) return ; eexit(2);main()int k; printf(*process management*nn); init(); printf(s1=%d, s2=%dn,s1,s2); printf(process1,process2,process3 are all in rea