操作系统课程设计--基于线程的多任务系统的实现

#include #include #include #define GET_INDOS 0X34 #define GET_GRIT_ERR 0X5D06 #define NTCB 4 /*TCB数量*/ #define NBUF 10 #define TIMEOUT 2 /*时间片轮转时间*/ #define MSIZE 50 /*线程的五种状态，即开始，完成，运行，就绪和阻塞*/ #define START -1 #define FINISH 0 #define RUNNING 1 #define READY 2 #define BLOCK 3 int timeCount=0; int currentTcb=-1; char far *indos_ptr = 0 ; char far *crit_err_ptr = 0 ; typedef int(far* codeptr)(); /*定义一个线程私有堆栈结构体*/ struct int_regs{ unsigned BP,DI,SI,DS,ES,DX,CX,BX,AX,IP,CS,Flags,Off,Seg; }; typedef struct{ int value; struct TCB *wq; }semaphore; semaphore empty={NBUF,NULL}; semaphore mutexbuf={1,NULL}; struct buffer{ int sender; int size; char message[MSIZE]; struct buffer *next; }*freebuff,*lastbuff; struct TCB{ unsigned char *stack; unsigned ss; unsigned sp; int priority; char state; char name[10]; struct buffer *mq; semaphore mutex; semaphore sm; struct TCB *next; }tcb[NTCB]; void InitBuff(); void freeBuffer(); void InitTCB(); void InitDos(); int DosBusy(); void destroy(int i); void over(); int create_thread(char *name, codeptr code, int stacklen, int priority); void TcbState(); int seekNext(); void interrupt(*old_int8)(void); void interrupt other_swtch(void); int finish(); void block(struct TCB **qp); void wakeup(struct TCB **qp); void p(semaphore *sem); void v(semaphore *sem); void insertBuff(struct buffer **mq,struct buffer *buff); struct buffer *getBuffer(); void send(char *receiver,char *a,int size); void receiveBackBuffer(struct buffer *buff); struct buffer *get_mq(struct buffer **qp); void receive(); void f1(); void f2(); void InitBuff() { int i; struct buffer *tempBuffer1,*tempBuffer2; tempBuffer1=(struct buffer *)malloc(sizeof(struct buffer)); freebuff=tempBuffer1; for(i=0;inext=tempBuffer2; tempBuffer1=tempBuffer2; } tempBuffer1->next=NULL; lastbuff=tempBuffer1; } void freeBuffer() { struct buffer *temp; int i; if(freebuff!=NULL&&freebuff->next!=NULL) { free(freebuff); return ; } while(freebuff->next!=NULL) { temp=freebuff; freebuff=freebuff->next; free(temp); } } void InitTCB() { int i; for(i=0;iDS=_DS; stack->ES=_ES; stack->Flags=0x200; stack->CS=FP_SEG(code); stack->IP=FP_OFF(code); /*over函数压入堆栈，在线程结束时，作为返回值*/ stack->Off=FP_OFF(over); stack->Seg=FP_SEG(over); /*将TCB私有堆栈的段址和栈顶指针记录到TCB中，在TCB切换时要用*/ tcb[freetcb].ss=FP_SEG(stack); tcb[freetcb].sp=FP_OFF(stack); /*printf("freetcb %d/n",tcb[freetcb].priority);*/ return freetcb; } void TcbState() { int i; for(i=0;ipri) { n_tcb=i; pri=tcb[i].priority; } } /*实现TCB的优先级的变化*/ for( i=1;i=TIMEOUT) { if(!DosBusy()) { /*printf("%s 's time is up/n",tcb[currentTcb].name);*/ tcb[currentTcb].ss=_SS; tcb[currentTcb].sp=_SP; if(tcb[currentTcb].state==RUNNING) { tcb[currentTcb].state=READY; } currentTcb=seekNext(); _SS=tcb[currentTcb].ss; _SP=tcb[currentTcb].sp; tcb[currentTcb].state=RUNNING; timeCount=0; } } enable(); }/*时间中断*/ void interrupt other_swtch(void) { disable(); if(tcb[currentTcb].state==FINISH) { currentTcb=seekNext(); tcb[currentTcb].state=RUNNING; _SS=tcb[currentTcb].ss; _SP=tcb[currentTcb].sp; } else { tcb[currentTcb].ss=_SS; tcb[currentTcb].sp=_SP; if(tcb[currentTcb].state==RUNNING) { tcb[currentTcb].state=READY; } currentTcb=seekNext(); _SS=tcb[currentTcb].ss; _SP=tcb[currentTcb].sp; tcb[currentTcb].state=RUNNING; } enable(); } int finish() { int i; disable(); for(i=1;inext!=NULL) { temp=temp->next; } temp->next=&tcb[currentTcb]; } tcb[currentTcb].next=NULL; other_swtch(); enable(); } /*qp为阻塞队列，截取队列的第一个放在就绪队列的末尾*/ void wakeup(struct TCB **qp) { struct TCB *blockHead; blockHead=(*qp); { if(blockHead!=NULL) { (*qp)=(*qp)->next; blockHead->state=READY; blockHead->next=NULL; } } } void p(semaphore *sem) { struct TCB **qp; disable(); sem->value=sem->value-1; if(sem->value<0) { qp=&(sem->wq); block(qp); } enable(); } void v(semaphore *sem) { struct TCB **qp; disable(); qp=&(sem->wq); sem->value=sem->value+1; if(sem->value<=0) { wakeup(qp); } enable(); } /*放到私有TCB缓冲队列末尾*/ void insertBuff(struct buffer **mq,struct buffer *buff) { struct buffer *temp; if(buff==NULL) { return; } buff->next=NULL; if((*mq)==NULL) { (*mq)=buff; } else { temp=*mq; while(temp->next!=NULL) { temp=temp->next; } temp->next=buff; } } /*freebuff指向队列的第一个*/ struct buffer *getBuffer() { struct buffer *bufList; bufList=freebuff; freebuff=freebuff->next; return (bufList); } void send(char *receiver,char *a,int size) { struct buffer *buff; int i, id=-1; disable(); for(i=0;isender=currentTcb; buff->size=size; buff->next=NULL; for(i=0;isize;i++) { buff->message[i]=*(a+i); } /*实现对TCB中的消息队列互斥操作*/ p(&tcb[id].mutex); insertBuff(&tcb[id].mq,buff); v(&tcb[id].mutex); v(&tcb[id].sm); enable(); } /*接受完后把buffer还给空闲缓冲*/ void receiveBackBuffer(struct buffer *buff) { lastbuff->next=buff; lastbuff=lastbuff->next; } struct buffer *get_mq(struct buffer **qp) { struct buffer *temp; temp=(*qp); (*qp)=(*qp)->next; temp->next=NULL; return (temp); } void receive() { struct buffer *buff=NULL; disable(); if(tcb[currentTcb].mq==NULL) { printf("now there is no message in message queue,then blocked %s/n!", tcb[currentTcb].name); enable(); p(&tcb[currentTcb].sm); return ; } enable(); p(&tcb[currentTcb].sm); p(&tcb[currentTcb].mutex); buff=get_mq(&(tcb[currentTcb].mq)); v(&tcb[currentTcb].mutex); printf("%s receive a message from %s: ", tcb[currentTcb].name, tcb[buff->sender].name ); printf("%s/n/n", buff->message); p(&mutexbuf); receiveBackBuffer(buff); v(&mutexbuf); v(&empty); } void f1() { int i,j,k; char a[MSIZE]="Hello f2!"; for(i=0;i<10;i++) { putchar('a'); for(j=0;j<10000;j++) { for(k=0;k<10000;k++); } } printf("/n"); for(i=0;i<3;i++) { printf("f1 is sending message to f2!/n"); send("f2",a,MSIZE); receive(); for(j=1;j<10000;j++) { for(k=0;k<10000;k++); } } } void f2() { int i,j,k; char a[MSIZE]="Hello f1!"; for(i=0;i<10;i++) { putchar('b'); for(j=0;j<10000;j++) { for(k=0;k<10000;k++); } } printf("/n"); for(i=0;i<3;i++) { printf("f2 is sending message to f1!/n"); send("f1",a,MSIZE); receive(); for(j=0;j<10000;j++) { for(k=0;k<10000;k++); } } } int main() { disable(); InitDos(); InitTCB(); InitBuff(); old_int8=getvect(8); strcpy(tcb[0].name,"main"); tcb[0].state=RUNNING; currentTcb=0; create_thread("f1",(codeptr)f1,1024,3); create_thread("f2",(codeptr)f2,1024,1); TcbState(); setvect(8,new_int8); other_swtch(); enable(); while(!finish()) { } tcb[0].name[0]='/0'; tcb[0].state=FINISH; setvect(8,old_int8); printf("all thread have finished!/n"); TcbState(); freeBuffer(); getch(); }