消息队列的简单达成
发布时间：2021-11-18 17:55:02 所属栏目：教程 来源：互联网
导读：消息队列：一个进程向另一个进程发送数据块 消息队列基于消息，管道基于字节流 消息队列是用链表实现 1.创建：int megget(key_t key, int msgflag) key:函数ftok()的返回值 msgflag:IPC_CREAT是创建新的消息队列；IPC_EXCL与IPC_CREAT一起使用，即如果要创建
|
消息队列：一个进程向另一个进程发送数据块 消息队列基于消息，管道基于字节流 消息队列是用链表实现 1.创建：int megget(key_t key, int msgflag) key:函数ftok()的返回值 msgflag:IPC_CREAT是创建新的消息队列；IPC_EXCL与IPC_CREAT一起使用，即如果要创建的消息队列已存在，则返回错误 成功：返回队列标识符 失败：-1 2.获取：ssize_t msgrcv(int msqid, void *msgp, size_t msgsz, long msgtyp, int msgflg) msqid:消息队列的识别码 msgp:指向消息缓冲区的指针，用来暂时存储发送和接收的消息，是用户自己定义的一个通用结构 struct msgbuf { long mtype; //消息类型，必须> 0 char mtext[__SIZE__]; //消息文本 } msgsz:消息大小 msgtyp:消息类型（>0，返回其类型为mtype的第一个消息） msgflg:控制函数行为（0表示忽略） 成功：返回拷贝到mtext数组的实际字节数 失败：-1 3.发送：int msgsnd(int msqid, void *msgp, size_t msgsz, int msgflg) 成功：返回0 失败：-1 4.设置属性：int msgctl(int msqid, int cmd, struct msqid_ds *buf) 对msqid标识的消息队列执行cmd操作 cmd操作：IPC_STAT(获取对应的msqid_ds的数据结构，保存在buf指定的地址空间) IPC_SET(设置消息队列的属性，保存在buf中) IPC_RMID(从内核删除msqid标识的消息队列) msqid_ds：描述队列当前状态 成功：0 失败：-1 comm.h #ifndef __COMM__ #define __COMM__ #include <stdio.h> #include <stdlib.h> #include <sys/ipc.h> #include <sys/msg.h> #include <sys/types.h> #include <string.h> #define __SIZE__ 1024 #define FILEPATH "/tmp/.msg1" #define ID 0 const int ser_send_type=1; const int cli_send_type=2; typedef struct msg_info { char mtext[__SIZE__]; long mtype; }msginfo; #endif client.h #ifndef __CLIENT__ #define __CLIENT__ #include "comm.h" int cli_start(); int cli_end(int); #endif client.c #include "client.h" int msg_id= -1; int cli_start() { //create the client's buf which storage the msg msginfo cli_info; //create the key key_t key= ftok(FILEPATH, ID); if(key< 0) { perror("ftok"); exit(1); } //get the ID of msg_queue msg_id= msgget(key, 0); if(msg_id< 0) { perror("cli get key id failed"); exit(2); } while(1) { //client said printf("client:>"); fgets(cli_info.mtext, __SIZE__, stdin); //write in the cli_info //when it will exit? if(strncasecmp(cli_info.mtext, "quit", 4)==0) { printf("client bye!n"); break; } cli_info.mtype= cli_send_type; //send the msg(send judge) if(msgsnd(msg_id, &cli_info, sizeof(cli_info.mtext),0)== -1) //send fail { perror("client send msg fail"); exit(3); } //receive the msg memset(cli_info.mtext, ' ', sizeof(cli_info.mtext)); //reset first if(msgrcv(msg_id, &cli_info, sizeof(cli_info.mtext), ser_send_type, 0)==-1) //receive fail { perror("client msgrcv fail"); exit(4); } printf("server:>%sn", cli_info.mtext); //the msg receive from server have storaged in the cli_info.mtext fflush(stdout); } return 0; } int cli_end(int id) { if(msgctl(id, IPC_RMID, NULL)==-1) //fail { perror("delete th msg_queue from kernel fail"); exit(5); } else { printf("delete the msg_queue from kernel successn"); return 0; } } static void delete_msg(void) { if(msg_id!= -1) //the msg_queue exist { cli_end(msg_id); } printf("delete the msg queue endn"); } int main(int argc,char *argv[]) { atexit(delete_msg); if(cli_start()==0) { printf("cli start successn"); } else { printf("cli start failedn"); } return 0; } server.h #ifndef __SERVER__ #define __SERVER__ #include "comm.h" int ser_start(); int ser_end(int); #endif server.c #include "server.h" int msg_id= -1; int ser_start() { //create the server's buf which storage the msg msginfo ser_info; //create the key key_t key= ftok(FILEPATH, ID); if(key< 0) { perror("ftok"); exit(1); } //get the ID of msg_queue msg_id= msgget(key, IPC_CREAT|IPC_CREAT|0666); if(msg_id< 0) { perror("ser get key id failed"); exit(2); } while(1) { //reveive the msg if(msgrcv(msg_id, &ser_info, sizeof(ser_info.mtext), cli_send_type, 0)==-1) //fail { perror("server msgrcv fail"); exit(3); } printf("client:>%sn",ser_info.mtext); //first,output the client's msg printf("server:>"); //then,server will said memset(ser_info.mtext, ' ', sizeof(ser_info.mtext)); //reset first fgets(ser_info.mtext, __SIZE__, stdin); //write in the ser_info //when it will exit? if(strncasecmp(ser_info.mtext, "quit", 4)==0) { printf("server bye!n"); break; } ser_info.mtype= ser_send_type; //send the msg if(msgsnd(msg_id, &ser_info, __SIZE__, 0)==-1) //fail { perror("server msgsnd fail"); exit(4); } fflush(stdout); } return 0; } int ser_end(int id) { if(msgctl(id, IPC_RMID, NULL)== -1) //fail { perror("delete the msg_queue from kernel fail"); exit(5); } else { printf("delete the msg_queue from kernel successn "); return 0; } } static void delete_msg(void) { if(msg_id!= -1) //the msg_queue exist { ser_end(msg_id); } printf("delete the msg_queue endn"); } int main(int argc, char *argv[]) { atexit(delete_msg); if(ser_start()==0) //success { printf("ser start successn"); } else { printf("ser start failedn"); } return 0; } Makefile .PHONY:all all:client server client:client.c gcc -o $@ $^ server:server.c gcc -o $@ $^ .PHONY:clean clean: rm -f client server  （编辑：南通站长网） 【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容! |
