C, Socket, pthread: read doesn't work on a new thread - c

Question

I'm making a client-server program in C using threads.
I've got this problem: on the server, on thread #1 (number_one), function "read" works fine. But when I create another thread #2 (number_two), on this one something goes wrong. Parameters are passed in the right way (I think).
-->thread number_one
...
char message[256];
int new_connection=accept(master_sock,NULL,NULL);
pthread_t temp
if(pthread_create(&temp , NULL , number_two , (void*) &new_connection))
{
perror("pthread_create failed");
exit(-2);
}
else
{
puts("number_two created");
if(read(new_connection, message, 256) > 0)
printf("Message from client is %s", message);
}
if(pthread_detach(temp))
{
perror("detach failed");
exit(-3);
}
...
---> thread number_two
void *number_two(void *sock_desc)
{
int sock = *(int*)sock_desc;
int read_size;
char client_message[2000];
read_size=read(sock, client_message, 256);
client_message[read_size]='\0';
return 0;
}
In "number_one", read waits an input from the client, and then it sets correctly the buffer "message".
In "number_two", read does not wait the client and does not set the buffer "client_message".
Thank you.

Answer 1

Please try my code? it works, I think it is the same with your code.
#include <stdio.h>
#include <stdbool.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <time.h>
#include <pthread.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <net/if.h>
#include <netdb.h>
#define INVALID_SOCKET_FD (-1)
int create_tcp_server_socket(unsigned short port, bool bind_local, int backlog,
char *caller_name)
{
int socket_fd = INVALID_SOCKET_FD;
struct sockaddr_storage server_addr;
unsigned int yes = 1;
// just try ipv4
if (socket_fd < 0 && (socket_fd = socket(PF_INET, SOCK_STREAM, 0)) >= 0) {
struct sockaddr_in *s4 = (struct sockaddr_in *)&server_addr;
setsockopt(socket_fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes));
memset(&server_addr, 0, sizeof(server_addr));
s4->sin_family = AF_INET;
s4->sin_port = htons(port);
if (bind_local)
s4->sin_addr.s_addr = htonl(INADDR_LOOPBACK);
else
s4->sin_addr.s_addr = htonl(INADDR_ANY);
if (bind(socket_fd, (struct sockaddr *)&server_addr,
sizeof(server_addr)) < 0) {
close(socket_fd);
printf("Server: Failed to bind ipv4 server socket.\n");
return INVALID_SOCKET_FD;
}
}
else if (socket_fd < 0) {
printf("Server: Failed to create server socket.\n");
return INVALID_SOCKET_FD;
}
if (listen(socket_fd, backlog) < 0) {
close(socket_fd);
printf("Server: Failed to set listen.\n");
return INVALID_SOCKET_FD;
}
return socket_fd;
}
pthread_t temp;
void *number_two(void *sock)
{
char buf[1024];
int fd = *(int *)sock;
int nread = read(fd, buf, 1024);
write(STDOUT_FILENO, buf, nread);
return NULL;
}
int main()
{
pid_t pid;
if ((pid = fork()) < 0) {
}
else if (pid > 0) { // parent, server
char buf[1024];
int fd = create_tcp_server_socket(8787, false, 10, "zz");
int new_fd = accept(fd, NULL, 0);
pthread_create(&temp, NULL, number_two, (void *)&new_fd);
}
else { // child, client
uint32_t ip;
struct hostent *hp = gethostbyname("localhost");
memcpy(&ip, hp->h_addr_list[0], hp->h_length);
struct sockaddr_in server_addr;
memset((char *)&server_addr, 0, sizeof(server_addr));
server_addr.sin_family = AF_INET;
server_addr.sin_addr.s_addr = ip;
server_addr.sin_port = htons(8787);
int fd = socket(AF_INET, SOCK_STREAM, 0);
connect(fd, (struct sockaddr *)&server_addr, sizeof(server_addr));
write(fd, "abcd", 4);
}
pause();
return 0;
}