IO进程线程Day8

让2个终端之间互相聊天，使用消息队列去实现

#include <myhead.h>
//使用消息队列实现两个进程的相互聊天
#define ERR_MSG(msg)  do{fprintf(stderr,"__%d__",__LINE__);\perror(msg);\}while(0)
int msgid;
typedef struct{long mtype;char text[256];
}msg_t;void *rtask(void *arg){msg_t buf;long rtype=*((long *)arg);while(1){memset(buf.text,0,sizeof(buf.text));if(msgrcv(msgid,&buf,sizeof(buf.text),rtype,0)<0){ERR_MSG("msgrcv");break;}if(0==strcmp(buf.text,"quit")){printf("user2 offline\n");break;}printf("\033[8Duser2:%s\n",buf.text);printf("请输入:");fflush(stdout);}pthread_exit(NULL);
}void *wtask(void *arg){msg_t buf;long wtype=*((long *)arg);buf.mtype=wtype;while(1){memset(buf.text,0,sizeof(buf.text));printf("请输入:");fgets(buf.text,sizeof(buf.text),stdin);buf.text[strlen(buf.text)-1]='\0';if(msgsnd(msgid,&buf,sizeof(buf.text),0)<0){ERR_MSG("msgsnd");break;}if(0==strcmp(buf.text,"quit")){printf("user1 offline\n");break;                                                     }}pthread_exit(NULL);
}int main(int argc, const char *argv[])
{//创建秘钥key_t key=ftok("/",19);if(key<0){ERR_MSG("ftok");return -1;}//创建消息队列msgid=msgget(key,IPC_CREAT|0664);if(msgid<0){ERR_MSG("msgget");return -1;}long rtype=1;long wtype=2;pthread_t rtid,wtid;if(pthread_create(&rtid,NULL,rtask,&rtype)!=0){ERR_MSG("rtask");return -1;}if(pthread_create(&wtid,NULL,wtask,&wtype)!=0){ERR_MSG("wtask");return -1;}pthread_join(rtid,NULL);pthread_join(wtid,NULL);//删除消息队列msgctl(msgid,IPC_RMID,0);return 0;
}

让2个终端之间互相聊天使用共享内存 + 信号灯集去实现

#include <myhead.h>
//使用共享内存和信号灯集实现两个进程聊天#define ERR_MSG(msg) do{fprintf(stderr,"__%d__",__LINE__);\perror(msg);\}while(0)
typedef struct{char buf[256];
}shm_t;void semwait(int semid,int sem_num){struct sembuf buf;buf.sem_num=sem_num;buf.sem_op=-1;buf.sem_flg=SEM_UNDO;semop(semid,&buf,1);
}
void sempost(int semid,int sem_num){struct sembuf buf;buf.sem_num=sem_num;buf.sem_op=1;buf.sem_flg=SEM_UNDO;semop(semid,&buf,1);
}
shm_t *addr;
int semid;
int shmid;
void sighandler(int signal){if(SIGCHLD==signal){while(waitpid(-1,NULL,0)>0);//删除共享内存的映射shmdt(addr);//删除共享内存shmctl(shmid,IPC_RMID,0);//删除信号灯集semctl(semid,0,IPC_RMID,0);exit(0);}
}int main(int argc, const char *argv[])
{//创建秘钥key_t key=ftok("/",7);if(key<0){ERR_MSG("ftok");return -1;}//创建共享内存shmid=shmget(key,sizeof(shm_t),IPC_CREAT|0664);if(shmid<0){ERR_MSG("shmget");return -1;}//将共享内存映射到进程的内存空间addr=shmat(shmid,NULL,0);if(addr==(void*)-1){ERR_MSG("shmat");return -1;}//创建信号灯集semid=semget(key,4,IPC_CREAT|0664);if(semid<0){ERR_MSG("semget");return -1;}//初始化信号灯集if(semctl(semid,0,SETVAL,1)<0){ERR_MSG("semctl");return -1;}if(semctl(semid,2,SETVAL,0)<0){ERR_MSG("semctl");return -1;}pid_t pid=fork();if(pid>0){//user1发送while(1){signal(SIGCHLD,sighandler);semwait(semid,0);memset(addr->buf,0,sizeof(addr->buf));printf("请输入:");fgets(addr->buf,sizeof(addr->buf),stdin);addr->buf[strlen(addr->buf)-1]='\0';sempost(semid,2);if(0==strcmp(addr->buf,"quit")){printf("user1 offline\n");break;}}exit(0);}else if(0==pid){//user1接收while(1){semwait(semid,3);if(0==strcmp(addr->buf,"quit")){printf("user2 offline\n");break;}printf("\033[8Duesr2:%s\n",addr->buf);printf("请输入:");fflush(stdout);memset(addr->buf,0,sizeof(addr->buf));sempost(semid,1);}exit(0);}else{ERR_MSG("fork");return -1;}return 0;
}