IO / day07 作业-编程知识

IO / day07 作业

1. 使用消息队列完成两个进程之间相互通信

代码

#include <myhead.h>//define a msg struct type
struct msgbuf
{long mtype; //消息类型char mtext[1024]; //消息正文大小};//macro msg size
#define SIZE (sizeof(struct msgbuf)-sizeof(long))int recv(int mtype_recv)
{//*-----snd-----	//1. create keykey_t key = ftok("/", 'k');if(key==-1){perror("error");return -1;}printf("key=%#x\n", key);//2. create msg queueint msgid = msgget(key, IPC_CREAT | 0664);if(msgid == -1){perror("msgget error");return -1;}printf("msgid=%d\n", msgid);//3. send msg to msg queue//define a msg varstruct msgbuf buf;while(1){//将消息从消息队列读取msgrcv(msgid, &buf, SIZE, mtype_recv, 0 );//param1: msg queue id//param2; buffer start address//param3: msg text size//param4: msg type//param5: if block, 0--> block; printf("recv msg=%s\n", buf.mtext);//if(strcmp(buf.mtext, "quit") == 0){break;}}//4. delete msg queueif ((msgctl(msgid, IPC_RMID, NULL)) == -1){perror("msgctl error");return -1;}  }void* task_recv(void* arg)
{int *pmtype_recv = (int *)arg;recv(*pmtype_recv);
}int main(int argc, const char *argv[])
{int mtype_snd = 0;int mtype_recv = 0;printf("plesae input msg type for sender:\n>");scanf("%d", &mtype_snd );printf("plesae input msg type for receiver:\n>");scanf("%d", &mtype_recv );int *pmtype_recv = &mtype_recv;pthread_t tid = -1;int res = pthread_create(&tid, NULL, task_recv, (void *)pmtype_recv );if(res !=0 ){printf("thread create error\n");return -1;}//*-----snd-----	//1. create keykey_t key = ftok("/", 'k');if(key==-1){perror("error");return -1;}printf("key=%#x\n", key);//2. create msg queueint msgid = msgget(key, IPC_CREAT | 0664);if(msgid == -1){perror("msgget error");return -1;}printf("msgid=%d\n", msgid);//3. send msg to msg queue//define a msg varstruct msgbuf buf;buf.mtype = mtype_snd;while(1){printf("please input msg to send:");scanf("%s", buf.mtext);//将消息从消息队列读取msgsnd(msgid, &buf, SIZE, 0 );//param1: msg queue id//param2; buffer start address//param3: msg text//param4: if block, 0--> block; printf("recv msg=%s\n", buf.mtext);//if(strcmp(buf.mtext, "quit") == 0){break;}}//4. delete msg queueif ((msgctl(msgid, IPC_RMID, NULL)) == -1){perror("msgctl error");return -1;}    	return 0;
}

运行结果