实验三-进程通信

1、实验三进程通信一 . 实验学时与类型学时： 2，课外学时：自定实验类型：设计性实验二 . 实验目的了解 Linux 的软中断、管道、消息队列、共享存储区等进程间通信方式。三 . 实验内容1. 软中断通信机制(1) 请编写一个程序：循环输出“ how are you? ”，在按下 Ctrl+C 后中断显示，输出 “Byebye! ”后退出程序。#include#includeint k=1;void int_func(int sig)/软中断处理函数 k=0; Int main() signal(SIGINT,int_func);/预置软中断信号处理函数 While(k=1)Printf( “

2、how are you?n ” );Printf(“ byebye! ” );(2)使用信号机制实现父子进程同步，父进程先输出#include#includeint k=1;void func(int sig) k=0; main()int pid;pid=fork();if(pid0)printf(“ An ” );kill(pid,12);A，然后子进程输出B。else if(pid=0) signal(12,func); while(k=1)sleep(1);printf(“ Bn ”);2. 管道机制(1) 父子进程通过管道传送一串字符。 要求：子进程随机从键盘输入一串字符， 通过管道

3、发给父进程，父进程从管道中将消息读出并显示出来。#include#includemain() int pid, fd2 ;char outpipe50, inpipe50;pipe(fd);pid=fork();if (pid=0)Printf(“ please input some message:n” );Fgets(inpipe,sizeof(inpipe),stdin);write(fd1,inpipe,50);else if (pid0);wait(0);Printf(“ father get this message:nread(fd0,outpipe,50);” );printf

4、(“ %sn” ,outpipe);（ 2 ）父子进程通过管道互相发送字符串。要求：子进程向父进程通过管道发送”child.”，父进程回送”I am father.”，父子进程将各自收到的字符串显示在屏幕上。I am#inlcude#include#includemain()int pid, fd2 ;char str150, str250;pipe(fd);pid=fork();if (pid=0)strcpy(str1,”I m child” );write(fd1,str1,strlen(str1);Sleep(1);read(fd0,str2,50);printf(“ Child re

5、ceived: %sn” ,str2);else if (pid0) read(fd0,str1,50);printf(“ Parent received:%sn”,str1);strcpy(str2,” I m father.” );write(fd1,str2,strlen(str2);3. 消息队列机制(1) 父进程及其子进程通过一条消息队列互相传送数据。#include#include#include#includeint msgqid,qid;struct msg long mtype; char mtext256;pmsg;cancelqueue() msgctl(msgqid,I

6、PC_RMID,0); exit(0);main() int pid; Pid=fork(); If (pid0) msgqid=msgget(75, 0777);printf(“ msg id: %dn”,msgqid);pmsg.mtype=1;*(int *)pmsg.mtext)=getpid();msgsnd(msgqid,&pmsg,sizeof(int),0);msgrcv(msgqid,&pmsg,256,getpid(),0);printf(“ A:receive msg from %dn,*(int *)pmsg.mtext);Else if(pid=0)signal(2,

7、cancelqueue);msgqid=msgget(75, 0777|IPC_CREAT);while(1)msgrcv(msgqid,&pmsg,256,1,0);qid=*(int *)pmsg.mtext;printf(“ B:receive msg from %dnpmsg.mtype=qid;*(int *)pmsg.mtext)=getpid();msgsnd(msgqid,&pmsg,sizeof(int),0);” ,qid);(2) 非父子进程之间实通过一条消息队列互相传递数据。A 进程：#include#include#include#includestruct msg

8、long mtype; char mtext256;pmsg;main()int msgqid,pid; msgqid=msgget(75, 0777);printf( “ msg id: %dn ” ,msgqid);pmsg.mtype=1;*(int *)pmsg.mtext)=getpid();msgsnd(msgqid,&pmsg,sizeof(int),0);msgrcv(msgqid,&pmsg,256,getpid(),0);printf(“ A:receive msg from %dn”,*(int *)pmsg.mtext);B 进程：#include#include#in

9、clude#includeint msgqid,pid;struct msg long mtype;char mtext256;pmsg;cancelqueue() msgctl(msgqid,IPC_RMID,0);exit(0);main()signal(2,cancelqueue);msgqid=msgget(75, 0777|IPC_CREAT);while(1) msgrcv(msgqid,&pmsg,256,1,0);pid=*(int *)pmsg.mtext;printf(“ B:receive msg from %dnpmsg.mtype=pid;*(int *)pmsg.m

10、text)=getpid();msgsnd(msgqid,&pmsg,sizeof(int),0);” ,pid);4. 共享内存机制(1) 编程实现基于共享内存的进程间通信。 要求：进程 A 通过共享内存将自己的进程号传递给进程 B。A:#include#includemain()int shmid;int *va;shmid=shmget(22,sizeof(*va),0666|IPC_CREAT);va=(int *)shmat(shmid, 0,0);*va=getpid();printf(“get A s pid:%dn” ,*va);shmdt(va);B:#include#inc

11、ludemain() int shmid; int *va;shmid=shmget(22,sizeof(*va),0666|IPC_CREAT);va=(int*)shmat(shmid, 0,0);printf(“ A s pid is :%dn” ,*va);shmdt(va);shmctl(shmid,IPC_RMID,0);(2) 若要通过共享内存实现进程A 与进程 B 互送进程号，可怎样编程实现？#include#includemain()int shmid; int *va;shmid=shmget(22,sizeof(*va),0666|IPC_CREAT);va=(int *

12、)shmat(shmid, 0,0);*va=getpid();printf(“ get A s pid:%dn” ,*va);Sleep(2);printf(“ B s pid is:%dn” ,*va)shmdt(va)B:#include#includemain() int shmid; int *va; shmid=shmget(22,sizeof(*va),0666|IPC_CREAT); va=(int*)shmat(shmid, 0,0);printf(“ A s pid is :%sn” ,*va);*va=getpid();printf(“ get B s pid:%dn”

13、,*va);shmdt(va);shmctl(shmid,IPC_RMID,0);5. SOCKET 进程通信（选做）编程实现基于 SOCKET的进程间通信，通过网络实现进程之间数据通信。要求：分别编写服务器端和客户端方程序，运行于不同终端，二者可相互进行通信。Server:#include #include #include #include #include #include #include int main()int server_sockfd = -1;int client_sockfd = -1;int client_len = 0;struct sockaddr_in serve

14、r_addr;struct sockaddr_in client_addr;/ 创建流套接字server_sockfd = socket(AF_INET, SOCK_STREAM, 0);/ 设置服务器接收的连接地址和监听的端口server_addr.sin_family = AF_INET;/指定网络套接字server_addr.sin_addr.s_addr = htonl(INADDR_ANY);/server_addr.sin_port = htons(9736);/绑定到接受所有 9736 端口IP地址的连接/绑定（命名）套接字bind(server_sockfd,(structso

15、ckaddr*)&server_addr,sizeof(server_addr);/ 创建套接字队列，监听套接字listen(server_sockfd, 5);/ 忽略子进程停止或退出信号signal(SIGCHLD, SIG_IGN);while(1)char ch = 0;client_len = sizeof(client_addr);printf(Server waitingn); /接受连接，创建新的套接字client_sockfd =accept(server_sockfd, (struct sockaddr*)&client_addr,&client_len);if(fork(

16、) = 0)/ 子进程中，读取客户端发过来的信息，处理信息，再发送给客户端read(client_sockfd, &ch, 1);sleep(5);ch+;write(client_sockfd, &ch, 1);close(client_sockfd);exit(0);else/ 父进程中，关闭套接字close(client_sockfd);Client:#include #include #include #include #include #include #include int main()int sockfd = -1;int len = 0;struct sockaddr_in

17、address;int result;char ch = A; /创建流套接字sockfd = socket(AF_INET, SOCK_STREAM, 0); /设置要连接的服务器的信息address.sin_family = AF_INET;/使用网络套接字address.sin_addr.s_addr = inet_addr(127.0.0.1);/服务器地址address.sin_port = htons(9736);/服务器所监听的端口len = sizeof(address);/连接到服务器result = connect(sockfd, (struct sockaddr*)&ad

18、dress, len);if(result = -1)perror(ops:clientn);exit(1);/ 发送请求给服务器write(sockfd, &ch, 1);/ 从服务器获取数据read(sockfd, &ch, 1);printf(char form server = %cn, ch);close(sockfd);exit(0);四 . 思考与总结(1) 请对比下列程序与实验 1(1) 在按下 Ctrl+C 之后的运行现象。int k=1;int main(void)while(k=1)printf(“ how are you?n” );printf(“Byebye!n” )

19、;(2)针对实验2(2)，你能否通过信号量机制来实现？若能，请给出相应代码及运行结果分析。#include #include #include#include #include #include union semunint val;struct semid_ds *buf;unsigned short *array;arg;/ 生成信号量int sem_creat(key_t key)int semid;semid = semget(key,1,IPC_CREAT|0666);if (-1 = semid)printf(create semaphore errorn);exit(-1);sem.val = 0;semctl(semid,0,SETVAL,arg);return semid;/ 删除信号量void del_sem(int semid)arg.val = 0;semctl(semid,0,IPC_RMID,arg);/pint p(int semid)struct sembuf sops=0,-1,IPC_NOWAIT;return