服务器编程入门（10）TCP回射服务器实现 - 并发

#i nclude "mtserver.h"

int main(int argc, char* argv[])
{
    checkArgc(argc, 2);
    
    const char* ip = argv[1];
    int port = atoi( argv[2] );

    /* 1 declare socket*/
    int listenfd, connfd;
    int ret;
    
    /* 2 initialize listen socket*/
    mySocket(listenfd);
    
    /* 3 server address */
    struct sockaddr_in servaddr;
    initSockAddr(servaddr, ip, port);
    
    /* 4 bind */
    myBind(listenfd,
	 	   (struct sockaddr*)&servaddr,
           sizeof(servaddr));
    
    /* 5 listen */
    myListen(listenfd, 5);
    
    /* handle SIGCHLD signal*/
    signal(SIGCHLD, handle_sigchild);
    
    /* 6 waiting for connecting */
    pid_t chipid;
    socklen_t clilen;
    struct sockaddr_in cliaddr;
    
    for(;;) {
	 	clilen = sizeof(cliaddr);
        std::cout << "Waiting for connecting ..." << std::endl;
        connfd = myAccept(listenfd, 
		 				  (struct sockaddr*)&cliaddr, 
                          &clilen); 
        printf("Connection %d established...\n", listenfd);
        if ( (chipid=fork()) == 0 ) {
		 	handle_recv(connfd);
        }
    }

} 

void handle_recv(int connfd) {
     
    char recvbuf[BUFSIZE];
    
    while(1) {
        memset( recvbuf, ‘\0‘, BUFSIZE );
        if ( recv(connfd, recvbuf,BUFSIZE,0) != 0) {
		 	if (!strcmp(recvbuf, "exit"))
                break;
            fprintf(stderr,"recv msg: %s\n", recvbuf);
            send(connfd, recvbuf, strlen(recvbuf), 0);
            fprintf(stderr,"send back: %s\n\n", recvbuf);
        }
    }
    close(connfd);
    exit(0);
}


void handle_sigchild(int signo)
{
    pid_t pid;
    int stat;
    
    while ( (pid = waitpid(-1, &stat, WNOHANG)) > 0 ) {
        fprintf(stderr,
                "child %d terminated\n",
                pid);
        return;
    } 
}

#include "mtclient.h"

int main(int argc, char* argv[])
{   
	if (argc <=2 ) {
        std::cout << "server ip and port needed." << std::endl;
        return 1;
    }
    
    int port = atoi(argv[2]);
    char* ip = argv[1];
    

    int sockfd;
    struct sockaddr_in servaddr;
	
	
    mySocket(sockfd);

    initSockAddr(servaddr,ip, port);
    
    myConnect(sockfd,
              (struct sockaddr*)&servaddr,
              sizeof(servaddr));
    
    handle_msg(sockfd);
    exit(0);
    
}

void handle_msg(int sockfd) {
    char sendbuf[BUFSIZE];
    char recvbuf[BUFSIZE];
    while(1) {
	 	memset( sendbuf, ‘\0‘, BUFSIZE );
        memset( recvbuf, ‘\0‘, BUFSIZE );
        
        printf("%s", "send msg:");
        gets(sendbuf);
        if (strlen(sendbuf) > 0)
		 	send(sockfd,sendbuf,strlen(sendbuf),0);
        if ( !strcmp(sendbuf, "exit"))
            break;
        recv(sockfd,recvbuf,BUFSIZE,0);
        printf("recv back:%s\n\n", recvbuf);
    }
    close( sockfd );
    return;
} 

#include <signal.h>
_sighandler_t signal ( int sig, _sighandler_t _handler );

for( ; ; ) {
    chilen = sizeof(cliaddr);
    if ( (connfd = accept(listenfd, (struct sockaddr* ) &cliaddr, &clilen )) < 0 )
    {
        if (errno == EINTR)    // 检测到错误类型为EINTR时，重启accept系统调用
            continue;
        else
            err_sys ("accept error");
    }
}

#include <sys/wait.h>
pid_t wait( int *statloc );
pid_t waitpid(pid_t pid, int *statloc, int options);

void sig_child(int signo)
{
    pid_t pid;
    int stat;
    while ( (pid = waitpid(-1, &stat, WNOHANG)) > 0 )
        printf("Child %d terminated\n", pid);
    return;
}