操作系统-多任务系统

1、#include <dos.h>#include <alloc.h>#include <stdlib.h>#include <stdio.h>#include <string.h>/*#include "indos.c"#include "exterr.c"*/#define GET_INDOS 0X34#define GET_GRIT_ERR 0X5D06#define NTCB 5#define NTEXT 20#define NBUF 5/*#define TL 3*/* state co

2、de */* null 0 not assigned */#define FINISHED 0#define RUNNING 1#define READY 2#define BLOCKED 3unsigned oldss,oldsp;static int current=0; /* the tcb index of the current process */int multstop=1;int timecount=0;int TL;int n =0;int buf1;char far *indos_ptr = 0 ; char far *crit_err_ptr = 0 ;/* the po

3、inter to the process's code */typedef int (far *codeptr)(void); /*定义了一个函数指针类型*/typedef struct int value; struct TCB *wq; semaphore;semaphore mutexfb=1,NULL;/* buf is a critical resource */semaphore sfb=NBUF,NULL;/* buf */semaphore mutex=1,NULL;semaphore sa=1,NULL,sb=0,NULL;struct buffer int id;

4、int size; char textNTEXT; struct buffer *next; bufNBUF,*freebuf;struct TCB int id; /* unique process id */ char name10; /* process's name given by user */ unsigned char *stack; /* the beginning address of the stack */ unsigned sp,ss; char state; /* the state of process */ unsigned *chan; /* even

5、t process is awainting */ struct buffer *mq; semaphore mutex; semaphore sm; struct TCB *next; /* link pointer */ tcbNTCB ;/* the registers pushed in the stack after entering an interrupt funtion */struct int_regs / unsigned bp,di,si,ds,es,dx,cx,bx,ax,ip,cs,flags;/;/*头文件的这个数据结构修改成这样 */struct int_regs

6、 unsigned bp,di,si,ds,es,dx,cx,bx,ax,ip,cs,flags,off,seg;/*struct char name10; codeptr code;tableNTCB="f1",f1; "f2",f2; "f3",f3; "f4",f4; ;*/void interrupt (*old_int8)(void);void interrupt new_int8(void);int create(char *name,codeptr code,int stck);void destro

7、y(int id);void over(void);void interrupt swtch(void);int all_finished(void);void free_all(void);void tcb_state(void);void InitTcb(void);int DosBusy(void) if(indos_ptr && crit_err_ptr) return (*indos_ptr|*crit_err_ptr); else return(-1);/*用于判断当前DOS是否处于繁忙状态*/void InitInDos() union REGS regs; st

8、ruct SREGS segregs; regs.h.ah=GET_INDOS; /*使用34H号系统功能调用*/ intdosx(&regs,&regs,&segregs); indos_ptr=MK_FP(segregs.es,regs.x.bx); if(_osmajor<3) crit_err_ptr=indos_ptr+1; /*严重错误在INDOS后一字节处*/ else if(_osmajor=3&&_osmajor=0) crit_err_ptr=indos_ptr-1; /*严重错误在INDOS前一字节处*/ else regs.

9、x.ax=GET_GRIT_ERR; intdosx(&regs,&regs,&segregs); crit_err_ptr=MK_FP(segregs.ds,regs.x.si); /*初始化DOS，取得INDOS标志和严重错误标志地址*/void InitTcb(void) int i; for(i=0;i<NTCB;i+) tcbi.stack=NULL; tcbi.state=FINISHED; tcbi.chan=NULL; 0='0' tcbi.next=NULL; tcbi.mq=NULL; tcbi.mutex.v

10、alue=1; tcbi.mutex.wq=NULL; tcbi.sm.value=0; tcbi.sm.wq=NULL; int create(char *name,codeptr code,int stck) struct int_regs far *r; int i,id=-1; unsigned char *ptr; for(i=0;i<NTCB;i+) if(tcbi.state=0) id=i; break; if(id=-1) return(0); disable(); tcbid.stack=(unsigned char *)malloc(stck); r=(struct

11、 int_regs *)(tcbi.stack+stck-1); r-; tcbid.ss=FP_SEG(r); tcbid.sp=FP_OFF(r); r->cs=FP_SEG(code); r->ip=FP_OFF(code); r->ds=_DS; r->es=_DS; r->flags=0x200; r->seg=FP_SEG(over); r->off=FP_OFF(over); tcbid.state=READY; for(i=0;i<10;i+,name+) if(i=*name)=NULL) break; tc

12、9='0' enable(); return(1);void destroy(int id) /*me:线程撤销函数*/ disable(); free(tcbid.stack); tcbid.stack=NULL; tcbid.state=FINISHED; printf("n * Thread %s is terminated。 *n",); 0='0' enable();void over(void) /*me:撤销线程并重新进行调度*/ destroy(current); swt

13、ch();void block(unsigned *chan,struct TCB *qp) int id; struct TCB *tcbp; id=current; tcbid.state=BLOCKED; tcbid.chan=chan; if(*qp)=NULL) (*qp)=&tcbid; else tcbp=*qp; while(tcbp->next!=NULL) tcbp=tcbp->next; tcbp->next=&tcbid; tcbid.next=NULL; swtch();void wakeup_first(struct TCB *qp

14、) int i; struct TCB *tcbp; if(*qp)=NULL) return; tcbp=(*qp); (*qp)=(*qp)->next; tcbp->state=READY; tcbp->chan=NULL; tcbp->next=NULL;void p(semaphore *sem) struct TCB *qp; disable(); sem->value=sem->value-1; if(sem->value<0) qp=&(sem->wq); block(unsigned *)sem,qp); enab

15、le();void v(semaphore *sem) struct TCB *qp; disable(); qp=&(sem->wq); sem->value=sem->value+1; if(sem->value<=0) wakeup_first(qp); enable();void interrupt swtch(void) int loop=0; disable(); /* save the old process */ tcbcurrent.ss=_SS; tcbcurrent.sp=_SP; if(tcbcurrent.state=RUNNIN

16、G) tcbcurrent.state=READY; /* find a new process and restore it */ if(+current=NTCB) current=0; while(tcbcurrent.state!=READY && loop+<NTCB-1) current+; if(current=NTCB) current=0; if(tcbcurrent.state!=READY) current=0; _SS=tcbcurrent.ss; _SP=tcbcurrent.sp; tcbcurrent.state=RUNNING; timec

17、ount=0; /* tcb_state();*/ enable();int all_finished(void) int i; for(i=1;i<NTCB;i+) if(tcbi.state!=FINISHED) return(0); return(1);void free_all(void) int i; for(i=0;i<NTCB;i+) if(tcbi.stack) 0='0' tcbi.state=FINISHED; free(tcbi.stack); tcbi.stack=NULL; void interrupt new_int8(

18、void) int loop=0; (*old_int8)(); if(+timecount<TL) return; if(DosBusy() return; disable(); tcbcurrent.ss=_SS; tcbcurrent.sp=_SP; if(tcbcurrent.state=RUNNING) tcbcurrent.state=READY; /* find a new process and restore it */ if(+current=NTCB) current=1; while(tcbcurrent.state!=READY && +loop

19、<NTCB-1) current+; if(current=NTCB) current=1; if(tcbcurrent.state!=READY) current=0; _SS=tcbcurrent.ss; _SP=tcbcurrent.sp; tcbcurrent.state=RUNNING; timecount=0;/* tcb_state();*/ enable();void tcb_state(void) int i; /* if(!multstop) return; */ printf("n"); for(i=0;i<NTCB;i+) printf(

20、"proc %d(%9s): ",i,); switch(tcbi.state) case READY:printf("READYn");break; case RUNNING:printf("RUNNINGn"); break; case FINISHED:printf("FINISHEDn"); break; case BLOCKED:printf("BLOCKEDn"); break; void init_buf(void) int i; for(i=0;i<NBU

21、F-1;i+) bufi.next=&bufi+1; bufi.next=NULL; freebuf=&buf0;struct buffer *getbuf(void) struct buffer *buff; buff=freebuf; freebuf=freebuf->next; return(buff);void insert(struct buffer *mq,struct buffer *buff) struct buffer *temp; if(buff=NULL) return; buff->next=NULL; if(*mq=NULL) *mq=bu

22、ff; else temp=*mq; while(temp->next!=NULL) temp=temp->next; temp->next=buff; struct buffer *remov(struct buffer *mq,int sender) struct buffer *p,*q,*buff; q=NULL; p=*mq; while(p->id!=sender)&&(p->next!=NULL) q=p; p=p->next; if(p->id=sender) buff=p; if(q=NULL) *mq=buff-&g

23、t;next; else q->next=buff->next; buff->next=NULL; return(buff); else return(NULL); void send(char *receiver,char *a,int size) struct buffer *buff; int i,id=-1; disable(); for(i=0;i<NTCB;i+) if(strcmp(receiver,)=0) id=i; break; if(id=-1) enable(); return; p(&sfb); p(&mute

24、xfb); buff=getbuf(); v(&mutexfb); buff->id=current; buff->size=size; buff->next=NULL; for(i=0;i<buff->size;i+,a+) buff->texti=*a; p(&tcbid.mutex); insert(&(tcbid.mq),buff); v(&tcbid.mutex); v(&tcbid.sm); enable();int receive(char *sender,char *b) int i,size,id=-

25、1; struct buffer *buff; disable(); for(i=0;i<NTCB;i+) if(strcmp(sender,)=0) id=i; break; if(id=-1) enable(); return(0); p(&tcbcurrent.sm); p(&tcbcurrent.mutex); buff=remov(&(tcbcurrent.mq),id); v(&tcbcurrent.mutex); if(buff=NULL) v(&tcbcurrent.sm); enable(); return(-1

26、); size=buff->size; for(i=0;i<buff->size;i+,b+) *b=buff->texti; p(&mutexfb); insert(&freebuf,buff); v(&mutexfb); v(&sfb); enable(); return(size);/*codeptr lookup(char *name) int i; for(i=0;i<NTCB;i+) strcmp(name,)=0) return(tablei.code); return(NULL);*/void

27、f1(void) long i,j,k; for(i=0;i<1000;i+) putchar('a'); for(j=0;j<1000;j+) for(k=0;k<100;k+); void f2(void) long i,j,k; for(i=0;i<100;i+) putchar('b'); for(j=0;j<1000;j+) for(k=0;k<100;k+); /*int n=0;*/void f3(void) long i,j,k; int temp; for(i=0;i<100;i+) temp=n; d

28、elay(5); temp+; n=temp; for(j=0;j<1000;j+) for(k=0;k<99;k+); void f4(void) long i,j,k; int temp; for(i=0;i<100;i+) temp=n; temp+; delay(10); n=temp; for(j=0;j<1000;j+) for(k=0;k<100;k+); /*semaphore mutex=1,NULL;*/void f5(void) long i,j,k; int temp; for(i=0;i<100;i+) p(&mutex);

29、 temp=n; delay(5); temp+; n=temp; v(&mutex); for(j=0;j<1000;j+) for(k=0;k<99;k+); void f6(void) long i,j,k; int temp; for(i=0;i<100;i+) p(&mutex); temp=n; temp+; delay(10); n=temp; v(&mutex); for(j=0;j<1000;j+) for(k=0;k<100;k+); /*int buf1;/semaphore sa=1,NULL,sb=0,NULL;*

30、/void cp1(void) int i; for(i=0;i<10;i+) n+; buf1=n; void iop1(void) int i,tem; for(i=0;i<10;i+) tem=buf1; printf("Out %d:%dn",i,tem); void cp(void) int i; for(i=0;i<10;i+) n+; p(&sa); buf1=n; v(&sb); void iop(void) int i,tem; for(i=0;i<10;i+) p(&sb); tem=buf1; v(&am

31、p;sa); printf("Out %d:%dn",i,tem); void sender(void) int i,j; char a10;loop: for(i=0;i<10;i+) strcpy(a,"message"); a7='0'+n; a8=0; send("receiver",a,strlen(a); printf("sender:Message "%s" has been sentn",a); n+; receive("receiver"

32、;,a); if (strcmp(a,"ok")!=0) printf("Not be committed,Message should be resended!n");/*接收进程没确认,需重新发送消息*/ goto loop; else printf("Committed,Communication is finished!n");/*发送者得到接收者的确认,通信结束*/void receiver(void) int i,j,size; char b10; for(i=0;i<10;i+) b0=0; while(size=

33、receive("sender",b)=-1); printf("receiver: Message is received-");/已接收到消息- for(j=0;j<size;j+) putchar(bj); printf("n"); strcpy(b,"ok"); send("sender",b,3);/* 发送确认消息 */void main(void) int sele=-1; char name10; InitInDos(); InitTcb(); old_int8=getve

34、ct(8); /* create thread 0 */ strcpy(,"main"); tcb0.state=RUNNING; current=0; for(;sele;) do clrscr(); printf("nnnt*n"); printf("t* 0.Quit Multi-Task System: *n");/*退出多任务系统*/ printf("t* 1.Threads perform in sequence way: *n");/*线索的"顺序"执行*/ pr

35、intf("t* 2.Threads perform in concurrent way: *n");/*线索的并发执行*/ printf("t* 3.Threads share critical resource(no mutual exclusion): *n");/*线索同时共享临界资源*/ printf("t* 4.Threads share critical resource(in mutual exclusion): *n");/*线索互斥共享临界资源*/ printf("t* 5.Threads running

36、 wihtout synchronism: *n");/*线索没做好同步时情况*/ printf("t* 6.Threads running in synchronism: *n");/*线索同步时的情况*/ printf("t* 7.Communication among threads: *n");/*线索间的通信*/ printf("t*nn"); printf("t Please enter the function num.(0-7):"); scanf("%d",&

37、sele); while(sele<0|sele>7) ; switch(sele) case 1: create("f1",(codeptr)f1,1024); create("f2",(codeptr)f2,1024); clrscr(); printf("t No deprivation in two threads' concurrent running: n");/*不剥夺方式下两个线索的并发执行*/ printf("t Thread f1 continuous output 'a

38、9; 1000 times ;n");/*其中线索f1不断输出字母a,共1000次*/ printf("t Thread f2 continuous output 'b' 1000 times 。n");/*而线索f2不断输出字母b,共100次*/ printf("t Press any key to continue!n");/*按任意键继续*/ getch(); swtch(); break; case 2: create("f1",(codeptr)f1,1024); create("f2&q

39、uot;,(codeptr)f2,1024); clrscr(); printf("t Round-Robin in two threads' concurrent running:n");/*时间片轮转方式下两个线索的并发执行*/ printf("t Thread f1 continuous output 'a' 1000 times ;n");/*其中线索f1不断输出字母a,共1000次*/ printf("t Thread f2 continuous output 'b' 1000 times 。n

40、");/*而线索f2不断输出字母b,共100次。*/ printf("t Please configurate the length of time slice(1/18.2):");/*请设置时间片的大小(单位为1/18.2秒)*/ scanf("%d",&TL); printf("t Press any key to continue!n"); getch(); setvect(8,new_int8); swtch(); break; case 3: n=0; create("f3",(cod

41、eptr)f3,1024); create("f4",(codeptr)f4,1024); clrscr(); printf("t Threads share critical resource(no mutual exclusion).n");/* 线索同时共享临界资源的情况*/ printf("t Thread f3 and f4 share the same variable parameter 'n'n");/*线索f3和f4共享一变量n*/ printf("t Thread f3 continuou

42、s add 1 to 'n' 100 times;n"); /*times线索f3不断对n进行加1操作,共进行100次*/ printf("t Thread f4 also continuous add 1 to 'n' 100 times;n");/*线索f4也不断对n进行加1操作,共进行100次*/ printf("t Result should be 200.n");/*因此,最后n的值应为200*/ printf("t Press any key to continue!n"); ge

43、tch(); TL=1; setvect(8,new_int8); swtch(); break; case 4: n=0; create("f3",(codeptr)f5,1024); create("f4",(codeptr)f6,1024); clrscr(); printf("t Threads share critical resource(in mutual exclusion): n");/*线索互斥共享临界资源*/ printf("t Thread f3 and f4 share the same varia

44、ble parameter 'n'n");/*线索f3和f4共享一变量n*/ printf("t Thread f3 continuous add 1 to 'n' 100 times;n");/*线索f3不断对n进行加1操作,共进行100次*/ printf("t Thread f4 also continuous add 1 to 'n' 100 times;n");/*线索f4也不断对n进行加1操作,共进行100次*/ printf("t Result should be 200.

45、n");/*因此,最后n的值应为200*/ TL=1; printf("t Press any key to continue!n"); getch(); setvect(8,new_int8); swtch(); break; case 5: n=0; create("iop",(codeptr)iop1,1024); create("cp",(codeptr)cp1,1024); clrscr(); printf("t Computing process and Output process concurren

46、tly running wihtout synchronism: n");/*没同步的计算进程和输出进程的并发执行*/ printf("t Computing process 'cp' continuous calculate and put the result into a buffer,n");/*并将其放入一缓冲区*/ printf("t Printing process 'iop' orderly fetch 'cp' and output it.n");/*打印进程iop依次取出cp放

47、入缓冲区中的数,将它输出出来*/ printf("t Here ,'cp' computed 10 results:0,1,2,3,4,5,6,7,8,9n");/*本例中,cp计算出十个数,分别为0,1,2,3,4,5,6,7,8,9*/ printf("t Press any key to continue!n"); getch(); TL=1; setvect(8,new_int8); swtch(); break; case 6: n=0; create("iop",(codeptr)iop,1024); cr

48、eate("cp",(codeptr)cp,1024); clrscr(); printf("t Computing process and Output process concurrently running in synchronism: n");/*经过同步的计算进程和输出进程的并发执行:*/ printf("t Computing process 'cp' continuous calculate and put the result into a buffer,nn");/*计算进程cp不断计算数,并将其放入一缓冲区,*/ printf("t