error in select(): invalid argument - c

Question

Here is my server code, dont know how i got
failed to select : Invalid argument
its work fine on my mac, but not on linux.
can someone tell me where i did wrong ?
Im just new begynniner in c programming.
server.c
int server(int port){
int request_sd, newfd;
socklen_t clientaddrlen;
fd_set masterList;
fd_set readFd;
int bind_adress = 0, listen_connect = 0;
int fd_max;
int select_client, i;
struct sockaddr_in server_adr;
struct sockaddr_in client_adr;
if (!getcwd(root_path, PATH_LEN))
{
perror("set path");
}
request_sd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
if (request_sd < 0)
{
perror("failed: ");
return -1;
}else printf("create new socket i complete: %d\n", request_sd);
memset(&server_adr, 0 , sizeof (struct sockaddr_in));
server_adr.sin_family = AF_INET;
server_adr.sin_addr.s_addr = INADDR_ANY;
server_adr.sin_port = htons(port);
int activate = 1;
if (setsockopt(request_sd, SOL_SOCKET, SO_REUSEADDR, &activate, sizeof(int)) == -1)
{
perror("setsockopt: ");
return -1;
}
bind_adress = bind(request_sd, (struct sockaddr*) &server_adr, sizeof(struct sockaddr_in));
if (bind_adress < 0 )
{
perror("failed to bind : ");
return -1;
}
listen_connect = listen(request_sd, 10);
if (listen_connect <0)
{
perror("failed to listen : ");
return -1;
}
printf("\nListening for connections on port: %d\n\n", port);
fflush(stdout);
FD_ZERO(&masterList);
FD_ZERO(&readFd);
FD_SET(request_sd, &masterList);
fd_max = request_sd;
while(1){
readFd = masterList;
if((select_client = select(fd_max+1, &readFd, NULL, NULL, NULL)) < 0){
perror("FAILED TO SELECT");
}
for ( i = 0; i <= fd_max; i++)
{
if(FD_ISSET(i,&readFd))
{
if(i == request_sd)
{
newfd = accept(request_sd, (struct sockaddr*) &client_adr,
(socklen_t *) &clientaddrlen);
if (newfd == -1 )
{
perror("failed to accept :");
return -1;
}
FD_SET(newfd, &masterList);
if (newfd > fd_max)
{
fd_max = newfd;
}

Answer 1

Since select() is complaining about a bad parameter, and you are passing only two parameters to it, that means either fd_max is invalid or readFd is invalid. The documentation states:
EINVAL
nfds is negative or the value contained within timeout is invalid.
Since you are not using the timeout parameter, look at your fd_max variable, make sure you are not overflowing it.
Aside from that, you should use fd_copy() instead of readFd = masterList on platforms that support it.
FD_COPY(&masterList, &readFd);
A better option is to use poll() or epoll() instead of select(). It is easier to manage, and it tells you the exact socket(s) that satisfied the wait so you don't have to hunt for them.