網路伺服器處理阻塞問題

標籤：

最近客戶採用採用多個進程來同時對snmp伺服器來set/get  ，有時候會造成網路伺服器 net-snmp 的阻塞而無伺服器反饋資訊

為了改善，自己寫了一個簡單伺服器，為了提高處理效果，建立子進程來處理，並由父進程來回收

 

代碼如下：

 

標頭檔：

socket_include.h

#include <stdio.h>#include <stdlib.h>#include <string.h>#include <unistd.h>#include <sys/socket.h>#include <netinet/in.h>

　　

 

 

server.c

#include <time.h>#include <stdio.h>#include <stdlib.h>#include <unistd.h>#include <termios.h>#include <string.h>#include <sys/ipc.h>#include <sys/sem.h>#include <sys/shm.h>#include "socket_include.h"#define MAXLINE 80#define SERV_PORT 1234struct serialdata{int cur[10][24];int mincur[10][24];int maxcur[10][24];int minTcur[10][3];int maxTcur[10][3];int minTvol[10][3];int maxTvol[10][3];int minTH[10][8];int maxTH[10][8];int Tcur[10][3];int Tvol[10][3];int temp[10][4];int hum[10][4];int water[10];int smoke[10];int door[10][2];int kwh[10][24];int Tpowerfactor[10][3];int Tkwh[10][3];int swicth[10][24];int outputnum[10];int online[10];int type[10];int m_s;int alramflag[10][24+3+3+9];//output cur vol th////////////////////////////////////////////////int numperswicth[6];int ondelaytime;int offdelaytime;char slavename[10][32];char outputname[10][24][32];};struct serialdata *memdata;struct serialdata *shmdata(){key_t shmkey;int shmid;shmkey=ftok("/",‘b‘);shmid=shmget(shmkey,sizeof(struct serialdata)*2,0666|IPC_CREAT);if(shmid==-1)return NULL;struct serialdata * addr;addr=(struct serialdata*)shmat(shmid,0,0);if(addr==(struct serialdata*)-1)return NULL;return addr;}void handler(int num) {       //我接受到了SIGCHLD的訊號啦       int status;       int pid = waitpid(-1, &status, WNOHANG);       if (WIFEXITED(status)) {           printf("The child %d exit with code %d\n", pid, WEXITSTATUS(status));       }   }   int main(){memdata = NULL;memdata = shmdata();if(memdata==NULL){return -1;}//網路服務pid_t pid;struct sockaddr_in servaddr, cliaddr;    socklen_t cliaddr_len;    int listenfd, connfd;    char buf[MAXLINE];    char str[INET_ADDRSTRLEN];    int i, n;int index=0;int outindex=0;char cmd1[256];char show[255];    listenfd = socket(AF_INET, SOCK_STREAM, 0);    bzero(&servaddr, sizeof(servaddr));    servaddr.sin_family = AF_INET;    servaddr.sin_addr.s_addr = htonl(INADDR_ANY);    servaddr.sin_port = htons(SERV_PORT);        bind(listenfd, (struct sockaddr *)&servaddr, sizeof(servaddr));    listen(listenfd, 20);    printf("Accepting connections ...\n");    while (1) {        cliaddr_len = sizeof(cliaddr);        connfd = accept(listenfd,                 (struct sockaddr *)&cliaddr, &cliaddr_len);             n = read(connfd, buf, MAXLINE);//讀取網路資料buf[n]=‘\0‘;        printf("received from %s at PORT %d,buf:%s\n",         inet_ntop(AF_INET, &cliaddr.sin_addr, str, sizeof(str)),         ntohs(cliaddr.sin_port),buf);signal(SIGCHLD, handler); pid=fork();        if(pid<0)        {               perror("fork error");          }        else if(pid==0)//子進程處理資料        {for(index=0;index<10;index++){for(outindex=0;outindex<24;outindex++){memset(cmd1,0,sizeof(char)*255);sprintf(cmd1,"OFF %d %d",index,outindex+1);if(strcmp(cmd1,buf)==0){printf("is in readcmd succed!\n");char sworder[255];//關輸出位for(n=0;n<2;n++){memdata->swicth[index][outindex]=1;memset(sworder,0,sizeof(char)*255);printf("\n");sprintf(sworder,"/clever/bin/order %d %d 2 1",index,outindex+1);system(sworder);printf("the off order is dnoe.\n");printf("\n");}break;}memset(cmd1,0,sizeof(char)*255);sprintf(cmd1,"ON %d %d",index,outindex+1);if(strcmp(cmd1,buf)==0){printf("is in readcmd succed!\n");//關輸出位char sworder[255];for(n=0;n<2;n++){memdata->swicth[index][outindex]=2;memset(sworder,0,sizeof(char)*255);printf("\n");sprintf(sworder,"/clever/bin/order %d %d 1 1",index,outindex+1);system(sworder);printf("the on order is dnoe.\n");printf("\n");}break;}memset(cmd1,0,sizeof(char)*255);sprintf(cmd1,"status %d %d",index,outindex+1);if(strcmp(cmd1,buf)==0){memset(show,0,sizeof(char)*255);sprintf(show,"status:%s\n",memdata->swicth[index][outindex]==0?"--":(memdata->swicth[index][outindex]==1?"OFF":"ON"));write(connfd, show, strlen(show));break;}}}//處理完成 write(connfd, "exit sucessed!\n", strlen("exit sucessed!\n"));close(connfd);//短串連結束            exit(0);}/*for (i = 0; i < n; i++)            buf[i] = toupper(buf[i]);write(connfd, buf, n);*/          //write(connfd, "exit sucessed!\n", strlen("exit sucessed!\n"));  // close(connfd);    }return 0;}

用戶端：　

#include "socket_include.h"#define MAXLINE 80#define SERV_PORT 1234int main(int argc, char *argv[]){    struct sockaddr_in servaddr;    char buf[MAXLINE];    int sockfd, n;    char *str;        if (argc != 2) {        fputs("usage: ./client message\n", stderr);        exit(1);    }    str = argv[1];        sockfd = socket(AF_INET, SOCK_STREAM, 0);    bzero(&servaddr, sizeof(servaddr));    servaddr.sin_family = AF_INET;    //inet_pton(AF_INET, "127.0.0.1", &servaddr.sin_addr);    inet_pton(AF_INET, "192.168.1.239", &servaddr.sin_addr);    servaddr.sin_port = htons(SERV_PORT);        connect(sockfd, (struct sockaddr *)&servaddr, sizeof(servaddr));    write(sockfd, str, strlen(str));    n = read(sockfd, buf, MAXLINE);buf[n]=‘\0‘;    printf("Response from server:%s\n",buf);    //write(STDOUT_FILENO, buf, n);    close(sockfd);    return 0;}

　　

測試程式：

#include <stdio.h>int main(){int i=0;for(i=0;i<100;i++){printf("./client ‘ON 0 9‘\n");system("./client ‘ON 0 9‘");sleep(1);system("./client ‘status 0 9‘");sleep(1);printf("./client ‘OFF 0 9‘\n");system("./client ‘OFF 0 9‘");sleep(1);system("./client ‘status 0 9‘");sleep(1);}return 0;}

　　

 

網路伺服器處理阻塞問題