processescommunication.cpp

程序模拟操作系统课程中的进程间通信

/*程序模拟进程间通信，调试并运行成功*/
/*Leon Kyd*/

#include<stdio.h>
#include<stdlib.h>
#include<malloc.h>
#define true 1
#define false 0
#define null 0
#define len sizeof(struct qnode)

struct qnode {
    int data;
    struct qnode *next;
};

struct qnode *createq() {
    int i;
    int qsize=10;
    struct qnode *p1,*p2,*head;
    head=p2=(struct qnode *)malloc(len);
    head->data=-1;
    for(i=1;i<qsize;++i) {
        p1=(struct qnode *)malloc(len);
        p2->next=p1;
        p1->data=-1;
        p2=p1;
    }p1->next=null;
    return(head);
}

struct qnode *gettail(struct qnode *head) {
    struct qnode *p;
    p=head;
    do {
        p=p->next;
    }while(p->next);
    return(p);
}

int qfull(struct qnode *tail) {
    struct qnode *t;
    t=tail;
    if(t->data!=-1) return(true);
    else return(false);
}

int qempty(struct qnode *head) {
    struct qnode *p;
    p=head;
    if(p->data==-1) return(true);
    else return(false);
}

void into(struct qnode *head,int *mes,int num) {
    struct qnode *p;
    int *m;
    int n;
    p=head;m=mes;n=num;
    do {
        if(p->data==-1) {
            p->data=*(m+n);
            break;
        }p=p->next;
    }while(p);
}

void out(struct qnode *head) {
    struct qnode *p;
    p=head;
    do {
        p->data=p->next->data;
        p=p->next;
    }while(p->data!=-1);
}

void qstate(struct qnode *head) {
    struct qnode *p;
    p=head;
    printf("The current state of the queue is:\n\t<");
    do {
        printf("%d**",p->data);
        p=p->next;
    }while(p->next);
    printf("%d>\n",p->data);
}


void main() {
    int *mes;
    int i,rnd,msize,num_into=0,num_out=0;
    struct qnode *head,*tail;
    
    printf("Please enter the size of the message array.\n");
    scanf("%d",&msize);
    
    printf("The data in each message are : \n");
    mes=(int *)malloc(msize*sizeof(int));
    for(i=0;i<msize;++i) {
        *(mes+i)=rand()/1500+1;
        printf("%d ",*(mes+i));
    }printf("\n");
    
    head=createq();
    qstate(head);
    tail=gettail(head);

    do {
        rnd=(rand()/2000) % 2;
        printf("\nrnd=%d ",rnd);
        if(rnd) {
            if(num_into>msize-1) {
                printf("  所有消息都已进入过队列!\n");
                continue;
    		}
            if(qfull(tail)) {
                printf("The queue is full! Input blocked! Wait!\n");
                continue;
    		}
            else {
                printf("  消息 %d 入队\n",*(mes+num_into));
                into(head,mes,num_into);
                ++num_into;
                qstate(head);
    		}
    	}
        else {
            if(num_out>msize-1) {
                printf("  所有消息都已出过队列!");
    		}
            if(qempty(head)) {
                printf("The queue is empty! Output blocked! Wait!\n");
                continue;
    		}
            else {
                printf("  消息 %d 出队\n",*(mes+num_out));
                out(head);
                ++num_out;
                qstate(head);
    		}
    	}
    }while(num_into<msize || num_out<msize);
    printf("\n所有消息都已进出过队列!\n");
}