Stop on "recv" function

[nima0102]

Hi
I have wrote one program in order to increase my programming skills in c.
my code is :

#include <stdlib.h>
#include <stdio.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>



#define RECIEVE_BUFFER_SIZE 1024


int main ()
{
	int Socket_Listen=0;
	int Socket_Accept=0;
	int Byte_Recieved=0;
	int i=0;
	fd_set Master;
	int Fd_Max=0;
	FD_ZERO(&Master);
	int Select_Return_Value=0;



	socklen_t addrlen=0;
	struct sockaddr_in Address;
	char * Message= "You are connected to this server :) . \n";
	char * Message_Recieved_OK="Hey I got your message\n";

	char * Recieved_Text;
	Recieved_Text=(char*)malloc(RECIEVE_BUFFER_SIZE);
	memset(Recieved_Text,0,RECIEVE_BUFFER_SIZE);

	Address.sin_family = AF_INET;
	Address.sin_addr.s_addr = INADDR_ANY;
	Address.sin_port = htons(10000);




	//Create Socket
	Socket_Listen = socket(AF_INET,SOCK_STREAM,0);
	if (Socket_Listen < 0)
	{
		perror("Could niot Create Socket!");
		exit(EXIT_FAILURE);
	}
	else
	{
		fcntl(Socket_Listen, F_SETFL, O_NONBLOCK);
	}

	if (bind(Socket_Listen,(struct sockaddr*)&Address,sizeof(Address)) <0)
	{
		perror("Could not bind!");
		exit(EXIT_FAILURE);
	}

	if (listen(Socket_Listen,3) < 0)
	{
		perror("Could not Listen on port.");
		exit(EXIT_FAILURE);

	}

	Fd_Max = Socket_Listen;
	FD_SET(Socket_Listen, &Master);


	addrlen=sizeof(Address);

	while (1)
	{
	 Select_Return_Value = select(Fd_Max +1,&Master,NULL,NULL,NULL);

	 if ( (Select_Return_Value < 0 ) && (errno!=EINTR))
	 {
		 perror("Problem in return Select Funstion!");
	 }
	 else
	 {
		 for (i=0; i <= Fd_Max; i++)
		 {
			if (FD_ISSET(i,&Master))
			{
				if (i == Socket_Listen)
				{
					//There is New Connection request
					Socket_Accept = accept(Socket_Listen,(struct sockaddr *)&Address,&addrlen);
						if (Socket_Accept < 0)
						{
							perror("Can Not Accept Any Connection");
							exit(EXIT_FAILURE);
						}
						FD_SET(Socket_Accept,&Master);
						if ( Socket_Accept > Fd_Max)
							Fd_Max =Socket_Accept;

						if (send(Socket_Accept,Message,strlen(Message),0) < 0 )
						{
							perror("Could not send to client!");
							exit(EXIT_FAILURE);
						}

				} else
				{

					Byte_Recieved=recv(i,Recieved_Text,RECIEVE_BUFFER_SIZE,0);
						if (Byte_Recieved < 0)
						{
							perror("Could not get data from client!");
							exit(EXIT_FAILURE);
						}else if (Byte_Recieved == 0)
						{
							printf ("Connection failed!");
							exit (EXIT_FAILURE);

						}else if (Byte_Recieved > 0)
						{
							printf("client sent %d byte to server.\n",Byte_Recieved);
							if (send(i,Message_Recieved_OK,strlen(Message_Recieved_OK),0) < 0 )
								{
									perror("Could not send to client the message!");
									exit(EXIT_FAILURE);
								}
							close(i);
							FD_CLR(i,&Master);
						}


				}



			}



		 }
	 }

	}

	return 0;
}

I need tow or more client can simultaneously connect to this server program.But when one client connects to server,program waits on "recv" function!so another clients only can connect to server without any data insert!!so until first client insert any input, program will wait on "recv" function.

Thanks for any help or guidance

[Ikaron]

Well that's what recv does, it waits to receive data sent by the client. In order to handle multiple clients you'll probably want to look into multithreading and handle each client with a new thread. (I built a series of linked list functions and a parser to handle these clients, this was before I learned about vectors).

I'm pretty new to socket programming, however, so take what I suggest with a grain of salt and know that there likely exists better ways to handle multiple clients than making a new thread for each client.

There will be all sorts of things that the server will have to (or you may want to have) handle, such as receiving a message from a client and broadcasting it back to every other client, handling multiple messages being sent at once, etc.. But it's enjoyable to come up with solutions to these problems on your own (at least for me it was) so I won't go about listing everything I did xD.

[nima0102]

Hi
Thanks for your reply
I want to test this method for exercise purpose. But I could not solve my problem.

Thanks for more help or guidance.