Linux socket:如何使send()等待recv()
我正在使用TCP协议创建一个简单的客户端 – 服务器应用程序.
我知道默认情况下. recv()将阻塞,直到另一方调用send()到此套接字. 换一种说法.是否有可能让每个send()等待另一方的recv()才能调用另一个send()? 说清楚我的问题.我将在这里发布一个简单的代码: client.c #include <sys/socket.h> #include <sys/types.h> #include <netinet/in.h> #include <netdb.h> #include <stdio.h> #include <poll.h> #include <string.h> #include <stdlib.h> #include <unistd.h> #include <errno.h> #include <arpa/inet.h> int main(int argc,char *argv[]) { int sockfd = 0; char sendBuff[1024]; struct sockaddr_in serv_addr; int i; if(argc != 2) { printf("n Usage: %s <ip of server> n",argv[0]); return 1; } if((sockfd = socket(AF_INET,SOCK_STREAM,0)) < 0) { printf("n Error : Could not create socket n"); return 1; } memset(&serv_addr,'0',sizeof(serv_addr)); serv_addr.sin_family = AF_INET; serv_addr.sin_port = htons(5000); if(inet_pton(AF_INET,argv[1],&serv_addr.sin_addr)<=0) { printf("n inet_pton error occuredn"); return 1; } if( connect(sockfd,(struct sockaddr *)&serv_addr,sizeof(serv_addr)) < 0) { printf("n Error : Connect Failed n"); return 1; } do{ memset(sendBuff,' ',sizeof(sendBuff)); sprintf(sendBuff,"This is line %d",i); send(sockfd,sendBuff,strlen(sendBuff),0); //sleep(1); }while(++i<100); return 0; } server.c #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <errno.h> #include <string.h> #include <sys/types.h> #include <time.h> int main(int argc,char *argv[]) { int listenfd = 0,connfd = 0; struct sockaddr_in serv_addr; char sendBuff[1025]; char recvBuff[100]; int i = 0; listenfd = socket(AF_INET,0); memset(&serv_addr,sizeof(serv_addr)); memset(sendBuff,sizeof(sendBuff)); serv_addr.sin_family = AF_INET; serv_addr.sin_addr.s_addr = htonl(INADDR_ANY); serv_addr.sin_port = htons(5000); bind(listenfd,(struct sockaddr*)&serv_addr,sizeof(serv_addr)); listen(listenfd,10); connfd = accept(listenfd,(struct sockaddr*)NULL,NULL); do{ memset(recvBuff,sizeof(recvBuff)); recv(connfd,recvBuff,sizeof(recvBuff),0); printf( "%sn",recvBuff); }while(++i<100); return 0; } 我期望在服务器端的结果是打印: This is line 0 This is line 1 This is line 2 This is line 3 ... 但是,实际结果是这样的: This is line 0 This is line 1This is line 2This is line3This is line 4 This is line 5This is line 6This is line 7This is line 8This is line 9This is line 10 This is line 11This is line 12... 但是这很容易解释:当客户端发出send()时,它没有等待服务器端的recv()完成,并且由于某种原因,服务器端recv()循环比客户端发送慢().因此,客户端上的几个send()可以堆叠在一起并由服务器作为整体接收. (我的解释是对的吗?) 实际上似乎有一个非常愚蠢和松散的解决方案.只需在循环中的每个send()之后添加一个sleep(1)(就像我注释掉的那样).我知道这将使代码效率非常低,并且如果recv()循环将花费更长的时间来实现一些其他复杂的操作(当程序变大时这显然是不可预测的),这将花费超过1秒.此解决方案失败! 那么是否有更好的方法让双方相互通信以确保由单个recv()接收的单个send()发送的消息? 解决方法
client.c
while(condition) { send() from client; recv() from server; } server.c recv() from client; while(condition) { send() from server; //acknowledge to client recv() from client; } (编辑:李大同) 【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! |
- linux – 无法使用’localhost’连接到MySQL,但使
- 在Linux Cluster中的计算机之间共享大型mmaped数
- ifconfig – 如何在linux中列出给定网络接口的所
- linux-kernel – 如何在不破坏Linux内核模块的情
- linux – YarnApplicationState:ACCEPTED:等待
- linux – Daemonized buildbot start
- linux – 在被监禁的环境中运行Haskell程序需要什
- linux – 如何找出导致巨大dentry_cache使用的原
- Linux常用命令详解
- linux – 解释非零vmstat“si / so”值