#include <iostream>
#include <sys/types.h>
#include <sys/socket.h>
#include <strings.h>
#include <string.h>
#include <unistd.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <pthread.h>

using namespace std;

//const unsigned port = 5100;
const unsigned MAXBUFLEN = 512;
pthread_mutex_t accept_lock = PTHREAD_MUTEX_INITIALIZER;
int serv_sockfd;

void *one_thread(void *arg) {
	int cli_sockfd;
	struct sockaddr_in cli_addr;
	socklen_t sock_len;
	ssize_t n;
	char buf[MAXBUFLEN];

	int tid = *((int *)arg);
	free(arg);

	cout << "thread " << tid << " created" << endl;
	for (; ;) {
		sock_len = sizeof(cli_addr);
		pthread_mutex_lock(&accept_lock);
		cli_sockfd = accept(serv_sockfd, (struct sockaddr *)&cli_addr, &sock_len);
		pthread_mutex_unlock(&accept_lock);

		cout << "thread " << tid << ": ";
		cout << "remote client IP == " << inet_ntoa(cli_addr.sin_addr);
		cout << ", port == " << ntohs(cli_addr.sin_port) << endl;

		while ((n = read(cli_sockfd, buf, MAXBUFLEN)) > 0) {
			buf[n] = '\0';
			cout << buf << endl;
			write(cli_sockfd, buf, strlen(buf));
		}
		if (n == 0) {
			cout << "client closed" << endl;
		} else {
			cout << "something wrong" << endl;
		}
		close(cli_sockfd);
	}
	return(NULL);
}

int main(int argc, char *argv[]) {
	struct sockaddr_in serv_addr;
	int port, number_thread;
	pthread_t tid;
	int *tid_ptr;

	if (argc != 3) {
		fprintf(stderr, "%s port number_thread\n", argv[0]);
		exit(1);
	}

	port = atoi(argv[1]);
	number_thread = atoi(argv[2]);

	cout << "port = " << port << " number of threads == " <<
		number_thread << endl;
	serv_sockfd = socket(AF_INET, SOCK_STREAM, 0);

	bzero((void*)&serv_addr, sizeof(serv_addr));
	serv_addr.sin_family = AF_INET;
	serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
	serv_addr.sin_port = htons(port);

	bind(serv_sockfd, (struct sockaddr *)&serv_addr, sizeof(serv_addr));

	listen(serv_sockfd, 5);

	int i;
	for (i = 0; i < number_thread; ++i) {
		tid_ptr = (int *)malloc(sizeof(int));
		*tid_ptr = i;
		pthread_create(&tid, NULL, &one_thread, (void *)tid_ptr);
	}

	for (;;) 
		pause();
}