How can I send socket id through pthread? - c++

Question

I have a server in a raspberry pi, and want to allow multithreading. The server is working. The client is in windows.
I believe I need to send the socket id through the pthread_create, but haven't found how. Is there anything else I need to send?
What is the best way to do it?
I've searched the internet, stackoverflow included, and tryed some resolutions, but they didn't work.
const int PORT = 12000;
TCPServer tcp;
pthread_t my_thread[MAXCLIENTQUEUE];
int clientID = 0;
int main()
{
tcp.setup(PORT);
int clientQueueSize = 0, threadJoin = 0;
void *res;
do {
socklen_t sosize = sizeof(tcp.clientAddress);
//realizar o accept
tcp.newsockfd[clientQueueSize] = accept(tcp.sockfd, (struct sockaddr*) & tcp.clientAddress, &sosize);
if (tcp.newsockfd[clientQueueSize] == -1)
{
cout << "Error accepting -> " << tcp.newsockfd[clientQueueSize] << endl;
tcp.detach();
}
cout << ">- accept: " << strerror(errno) << " / codigo: " << tcp.newsockfd[clientQueueSize] << " - Endereco: " << inet_ntoa(tcp.clientAddress.sin_addr) << endl;
clientID++;
cout << ">>> client accepted" << " | Client ID: " << clientID << endl;
// criar threads
int ret = pthread_create(&my_thread[clientQueueSize], NULL, messenger, &tcp.newsockfd[clientQueueSize]);
cout << ">- pthread: " << strerror(errno) << " / codigo: " << ret << endl;
if (ret != 0) {
cout << "Error: pthread_create() failed\n" << "thread_n " << my_thread[clientQueueSize] << endl;
exit(EXIT_FAILURE);
}
cout << "thread n " << my_thread[clientQueueSize] << endl;
clientQueueSize++;
}
while (clientQueueSize < MAXCLIENTQUEUE);
pthread_exit(NULL);
return 0;
}
The server accepts multiple connections but only sends messages to the first client, the others connected successfully, but never receive messages.
I want for the server to be able to send messages to all the clients.

Answer 1

You have to create threads for all sockets.
Or, use Windows-depended async select methods.
P.S. Forget pthreads and use the standard std::thread.
map<SOCKET,std::string> clients;
void newclient(SOCKET x)
{
for(;;)
{
int r = recv(x,...);
if (r == 0 || r == -1)
break;
}
// remove it from clients, ensure proper synchronization
}
void server()
{
SOCKET x = socket(...);
bind(x,...);
listen(x,...);
for(;;)
{
auto s = accept(x,...);
if (s == INVALID_SOCKET)
break;
// save to a map, for example, after ensuring sync with a mutex and a lock guard
m[s] = "some_id";
std::thread t(newclient,s);
s.detach();
}
}
int main() //
{
// WSAStartup and other init
std::thread t(server);
t.detach();
// Message Loop or other GUI
}