收不到的原因是FD_ISSET函数一直没有检测到客户端那边有数据发过来,从而recvfrom以后没有被调用。为什么呢?udp应该也可以用select的。没有用select的时候(直接用recvfrom阻塞接收的方式),每个线程是可以接收到客户端发过来的数据的。服务器代码:
#include <sys/socket.h>
#include <unistd.h>
#include <string.h>
#include <stdio.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <pthread.h>
#include <signal.h>#define MAXLINE 80
#define SERV_PORT 8888
typedef struct thread_para
{
int sockfd; /* 上传文件名 */
struct sockaddr *pcliaddr; /* transID */
socklen_t clilen;
int thIndex; /* 线程索引 */
}THREAD_PARA;void do_echo(int sockfd,struct sockaddr *pcliaddr,socklen_t clilen,int thx)
{
int n,m;
socklen_t len;
char mesg[MAXLINE];
char mesg1[MAXLINE];
fd_set readfds;
struct timeval authtime;authtime.tv_usec = 0L;
authtime.tv_sec = (long)100;
FD_ZERO (&readfds);
FD_SET (sockfd, &readfds);for(;;)
{
if(select(sockfd,&readfds,NULL,NULL,&authtime)< 0)
{printf("select fail");return;}if (FD_ISSET(sockfd, &readfds)) {
printf("%d\n",thx);
len = clilen;
/* waiting for receive data */
n = recvfrom(sockfd,mesg,MAXLINE,0,pcliaddr,&len);
/* sent data back to client */if(n>0)
{printf("n:%d thx:%d\n",n,thx);}
sendto(sockfd,mesg,n,0,pcliaddr,len);
}
}
}void * TestCaseFunc(void *para)
{
THREAD_PARA *pArr = (THREAD_PARA *)para;do_echo(pArr->sockfd,pArr->pcliaddr ,pArr->clilen,pArr->thIndex);
if(NULL != para)
free(para); return NULL;
}
int main(void)
{
int threadNum=0,MyThreadNum=3;
int sockfd;
pthread_t h_thread[5000];
struct sockaddr_in servaddr,cliaddr;
sockfd = socket(AF_INET,SOCK_DGRAM,0); /* create a socket */
/* init servaddr */
bzero(&servaddr,sizeof(servaddr));
servaddr.sin_family = AF_INET;
servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
servaddr.sin_port = htons(SERV_PORT);
/* bind address and port to socket */
if(bind(sockfd,(struct sockaddr *)&servaddr,sizeof(servaddr)) == -1)
{
perror("bind error");
exit(1);
}
/*do_echo(sockfd,(struct sockaddr *)&cliaddr,sizeof(cliaddr));*/
for (threadNum=0;threadNum < MyThreadNum; threadNum++)
{
THREAD_PARA *pArr = (THREAD_PARA *)malloc(sizeof(THREAD_PARA));
pthread_t thid;
pArr->pcliaddr = (struct sockaddr *)&cliaddr;
pArr->sockfd = sockfd;
pArr->clilen = sizeof(cliaddr);
pArr->thIndex = threadNum+1;
if (pthread_create( &h_thread[threadNum], NULL, TestCaseFunc, pArr) != 0) {
exit(-1);
}
if (!h_thread[threadNum])
{
printf("Create Thread [%d] failed !!\n",threadNum);
exit(-1);
}
else
printf("Create Thread [%d] OK !!\n",threadNum);
} printf("All Thread Create successed!!!\n");while(1){sleep(1000);
}
/* 等待全部线程结束 */
for (threadNum=0;threadNum<MyThreadNum;threadNum++)
{
pthread_join(h_thread[threadNum], NULL);
}
return 0;
}客户端代码:
#include <sys/socket.h>
#include <unistd.h>
#include <string.h>
#include <stdio.h>
#include <arpa/inet.h>
#include <stdlib.h>
#define MAXLINE 80
#define SERV_PORT 8888
void do_cli(FILE *fp,int sockfd,struct sockaddr *pservaddr,socklen_t servlen)
{
int n;
char sendline[MAXLINE],recvline[MAXLINE + 1];
/* connect to server */
if(connect(sockfd,(struct sockaddr *)pservaddr,servlen) == -1)
{
perror("connect error");
exit(1);
}
while(fgets(sendline,MAXLINE,fp) != NULL)
{
/* read a line and send to server */
write(sockfd,sendline,strlen(sendline));
/* receive data from server */
n = read(sockfd,recvline,MAXLINE);
if(n == -1)
{
perror("read error");
exit(1);
}
recvline[n] = 0; /* terminate string */
fputs(recvline,stdout);
}
}
int main(int argc,char **argv)
{
int sockfd;
struct sockaddr_in servaddr;
/* check args */
if(argc != 2)
{
printf("usage: udpclient \n");
exit(1);
}
/* init servaddr */
bzero(&servaddr,sizeof(servaddr));
servaddr.sin_family = AF_INET;
servaddr.sin_port = htons(SERV_PORT);
if(inet_pton(AF_INET,argv[1],&servaddr.sin_addr) <= 0)
{
printf("[%s] is not a valid IPaddress\n",argv[1]);
exit(1);
}
sockfd = socket(AF_INET,SOCK_DGRAM,0);
do_cli(stdin,sockfd,(struct sockaddr *)&servaddr,sizeof(servaddr));
return 0;
}
#include <sys/socket.h>
#include <unistd.h>
#include <string.h>
#include <stdio.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <pthread.h>
#include <signal.h>#define MAXLINE 80
#define SERV_PORT 8888
typedef struct thread_para
{
int sockfd; /* 上传文件名 */
struct sockaddr *pcliaddr; /* transID */
socklen_t clilen;
int thIndex; /* 线程索引 */
}THREAD_PARA;void do_echo(int sockfd,struct sockaddr *pcliaddr,socklen_t clilen,int thx)
{
int n,m;
socklen_t len;
char mesg[MAXLINE];
char mesg1[MAXLINE];
fd_set readfds;
struct timeval authtime;authtime.tv_usec = 0L;
authtime.tv_sec = (long)100;
FD_ZERO (&readfds);
FD_SET (sockfd, &readfds);for(;;)
{
if(select(sockfd,&readfds,NULL,NULL,&authtime)< 0)
{printf("select fail");return;}if (FD_ISSET(sockfd, &readfds)) {
printf("%d\n",thx);
len = clilen;
/* waiting for receive data */
n = recvfrom(sockfd,mesg,MAXLINE,0,pcliaddr,&len);
/* sent data back to client */if(n>0)
{printf("n:%d thx:%d\n",n,thx);}
sendto(sockfd,mesg,n,0,pcliaddr,len);
}
}
}void * TestCaseFunc(void *para)
{
THREAD_PARA *pArr = (THREAD_PARA *)para;do_echo(pArr->sockfd,pArr->pcliaddr ,pArr->clilen,pArr->thIndex);
if(NULL != para)
free(para); return NULL;
}
int main(void)
{
int threadNum=0,MyThreadNum=3;
int sockfd;
pthread_t h_thread[5000];
struct sockaddr_in servaddr,cliaddr;
sockfd = socket(AF_INET,SOCK_DGRAM,0); /* create a socket */
/* init servaddr */
bzero(&servaddr,sizeof(servaddr));
servaddr.sin_family = AF_INET;
servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
servaddr.sin_port = htons(SERV_PORT);
/* bind address and port to socket */
if(bind(sockfd,(struct sockaddr *)&servaddr,sizeof(servaddr)) == -1)
{
perror("bind error");
exit(1);
}
/*do_echo(sockfd,(struct sockaddr *)&cliaddr,sizeof(cliaddr));*/
for (threadNum=0;threadNum < MyThreadNum; threadNum++)
{
THREAD_PARA *pArr = (THREAD_PARA *)malloc(sizeof(THREAD_PARA));
pthread_t thid;
pArr->pcliaddr = (struct sockaddr *)&cliaddr;
pArr->sockfd = sockfd;
pArr->clilen = sizeof(cliaddr);
pArr->thIndex = threadNum+1;
if (pthread_create( &h_thread[threadNum], NULL, TestCaseFunc, pArr) != 0) {
exit(-1);
}
if (!h_thread[threadNum])
{
printf("Create Thread [%d] failed !!\n",threadNum);
exit(-1);
}
else
printf("Create Thread [%d] OK !!\n",threadNum);
} printf("All Thread Create successed!!!\n");while(1){sleep(1000);
}
/* 等待全部线程结束 */
for (threadNum=0;threadNum<MyThreadNum;threadNum++)
{
pthread_join(h_thread[threadNum], NULL);
}
return 0;
}客户端代码:
#include <sys/socket.h>
#include <unistd.h>
#include <string.h>
#include <stdio.h>
#include <arpa/inet.h>
#include <stdlib.h>
#define MAXLINE 80
#define SERV_PORT 8888
void do_cli(FILE *fp,int sockfd,struct sockaddr *pservaddr,socklen_t servlen)
{
int n;
char sendline[MAXLINE],recvline[MAXLINE + 1];
/* connect to server */
if(connect(sockfd,(struct sockaddr *)pservaddr,servlen) == -1)
{
perror("connect error");
exit(1);
}
while(fgets(sendline,MAXLINE,fp) != NULL)
{
/* read a line and send to server */
write(sockfd,sendline,strlen(sendline));
/* receive data from server */
n = read(sockfd,recvline,MAXLINE);
if(n == -1)
{
perror("read error");
exit(1);
}
recvline[n] = 0; /* terminate string */
fputs(recvline,stdout);
}
}
int main(int argc,char **argv)
{
int sockfd;
struct sockaddr_in servaddr;
/* check args */
if(argc != 2)
{
printf("usage: udpclient \n");
exit(1);
}
/* init servaddr */
bzero(&servaddr,sizeof(servaddr));
servaddr.sin_family = AF_INET;
servaddr.sin_port = htons(SERV_PORT);
if(inet_pton(AF_INET,argv[1],&servaddr.sin_addr) <= 0)
{
printf("[%s] is not a valid IPaddress\n",argv[1]);
exit(1);
}
sockfd = socket(AF_INET,SOCK_DGRAM,0);
do_cli(stdin,sockfd,(struct sockaddr *)&servaddr,sizeof(servaddr));
return 0;
}
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