Hey,
Im new here, just joined, mainly due to the issue I'm asking about. This isn't the cleantest code in the world, especially since its been messed up to hell trying to find this leak :D . I've got some code that works how it should fine, i'ts still in the very early stages and is only a small piece of what it will be once done. But anyway moving on to my problem, while it works, there seems to be a memory leak, a large one. Its the begginings of some server software, and it accepts connections, allocates a slot to them and creates a thread to handle there request/operation, whatever you wnat to call it. Atm all it can do is query a mysql database to see if they're username/password are valid.
The problem is the more threads are made, the higher its memory usage gets, even though when a thread exits, it should, as far as i can tell be freeing all the memory it used. If no connections are being made, thus no threads being made, and just sitting idle, then the memory usage stops rising, but it doesnt drop at all. It just sits there. I've had it using over 600MB on linux before which is crazy. I just can't figure out where the leak is, I can't see anywhere in the code I've written that I'm leaking, its only 200 lines so far.
There are 3 sources and 3 headers atm, I've included below:
The header for main.cpp:
#ifndef MAIN_H
#define MAIN_H
#include <iostream>
#include <SDL/SDL.h>
#include <SDL/SDL_net.h>
#include <string>
#include <map>
#include <my_global.h>
#include <mysql.h>
using namespace std;
#ifdef main
#undef main
#endif
unsigned long long int getCurrentTime();
#endif
Main.cpp:
#include "main.h"
#include "tcp_connect.h"
#include "auth.h"
#include <sys/timeb.h>
/************ Function Prtotypes *********************************************/
void clean(void);
static tcp_handler * tcpserver;
/*****************************************************************************/
int main(int argc, char *argv[])
{
atexit(clean);
tcpserver = new tcp_handler();
tcpserver->connect();
return 0;
}
void clean(void)
{
SDL_Quit();
delete tcpserver;
}
unsigned long long int getCurrentTime()
{
struct timeb currentTime;
unsigned long long int retval = 0ULL;
ftime(¤tTime);
retval = (unsigned long long int)((currentTime.time * 1000ULL) + currentTime.millitm);
return retval;
}
The header for tcp_connect.cpp:
#ifndef TCP_CONNECT_H
#define TCP_CONNECT_H
#define SERVER_PORT 26000
#define PACKET_SIZE 4096
#define SLOTS 100
class tcp_handler
{
public:
tcp_handler();
~tcp_handler(){};
int connect(void);
static int op_handler(void * sdata);
private:
int slotsFree();
TCPsocket sd, csd, slotray[SLOTS]; /* Socket descriptor, Client socket descriptor */
IPaddress ip, *remoteIP;
int slot_num;
typedef struct socket_ptr
{
TCPsocket csd; // Keep this
int slot_num;
} sptr;
};
#endif
tcp_connect.cpp:
#include "main.h"
#include "tcp_connect.h"
#include "auth.h"
char slot_tracker[SLOTS];
tcp_handler::tcp_handler()
{
memset(&slot_tracker, 0, SLOTS);
}
int tcp_handler::connect(void)
{
if (SDLNet_Init() < 0)
{
fprintf(stderr, "SDLNet_Init: %s\n", SDLNet_GetError());
exit(EXIT_FAILURE);
}
/* Resolving the host using NULL make network interface to listen */
if (SDLNet_ResolveHost(&ip, NULL, SERVER_PORT) < 0)
{
fprintf(stderr, "SDLNet_ResolveHost: %s\n", SDLNet_GetError());
exit(EXIT_FAILURE);
}
/* Open a connection with the IP provided (listen on the host's port) */
if (!(sd = SDLNet_TCP_Open(&ip)))
{
fprintf(stderr, "SDLNet_TCP_Open: %s\n", SDLNet_GetError());
exit(EXIT_FAILURE);
}
/* Wait for a connection, bind socket */
while (1)
{
/* This checks sd for a pending connection.
If there is one, accept that, and open a new socket for communicating */
if ((csd = SDLNet_TCP_Accept(sd)))
{
slot_num = slotsFree();
if(slot_num == -1)
{
SDLNet_TCP_Close(csd);
cout << "Connect Refused - No Slots Free" << endl;
}
else
{
cout << "Connection Accepted - Slot: " << slot_num << endl;
slotray[slot_num] = csd;
slot_tracker[slot_num] = 1;
/* Now we can communicate with the client using csd socket
* sd will remain open waiting for other connections */
/*thread creation here************************************************/
/*create thread with op_handler function pasing socket csd, being the new connection*/
sptr * stemp = new sptr;
stemp->csd = slotray[slot_num];
stemp->slot_num = slot_num;
if(!SDL_CreateThread(op_handler, stemp))
{
cout << "Error creating thread" << endl;
}
}
}
}
}
/*************************************************************************************************/
int tcp_handler::op_handler(void * sdata)
{
sptr * stemp = (sptr *)sdata;
char packet[PACKET_SIZE];
unsigned short op;
cout << sdata << "\t" << stemp << endl;
if(SDLNet_TCP_Recv(stemp->csd, &packet, PACKET_SIZE) < 0)
{
cout << "ERROR: No Packet Recieved. Exiting..." << endl;
//exit(1);
}
else
{
op = packet[0];
op <<= 8;
op |= packet[1];
switch (op)
{
case 1:
auth_handler::auth_packet_handler(packet);
break;
}
}
SDLNet_TCP_Close(stemp->csd);
slot_tracker[stemp->slot_num] = 0;
delete stemp;
return 0;
}
int tcp_handler::slotsFree()
{
int i;
for(i=0; i<SLOTS; i++)
{
if(!slot_tracker)
{
return i;
}
}
return -1;
}
The header for auth.cpp:
#ifndef AUTH_H
#define AUTH_H
#define LOGIN_UNAME_LEN 32
#define LOGIN_PHASH_LEN 30
class auth_handler
{
public:
auth_handler(){};
~auth_handler(){};
static void auth_packet_handler(char *);
private:
};
#endif
auth.cpp:
#include "main.h"
#include "auth.h"
void auth_handler::auth_packet_handler(char * packet)
{
MYSQL *conn = mysql_init(NULL);
MYSQL_RES *Q_Res;
MYSQL_ROW Q_Row;
char SQL[256], username[32], passkey[30];
int num_rows;
std::string temp;
memset(&username, 0, 32);
memset(&passkey, 0, 30);
mysql_init(conn);
if(!mysql_real_connect(conn, "localhost", "root", "", "zero-sum", 0, NULL, 0))
{
cout << "ERROR: Unable to connect to MySQL" << endl;
mysql_close(conn);
exit(1);
}
strncpy(username, &packet[2], strlen(&packet[2]) + 1);
strncpy(passkey, &packet[34], strlen(&packet[34]) + 1);
sprintf(SQL, "SELECT * FROM `account status` WHERE exists (SELECT `userid` FROM `users` WHERE `key` = '%s' AND `username` = '%s')", passkey, username);
mysql_query(conn, SQL);
if (!(Q_Res = mysql_store_result(conn)))
{
printf("ERROR storing results for query string:\r\n%s\r\n", SQL);
printf("Wrong username or password\r\n");
//should kill thread here
}
else
{
// Shouldn't happen, but better check
num_rows = mysql_num_rows(Q_Res);
if (num_rows == 0)
{
exit (-1); // Invalid username or password
}
if (num_rows > 1)
{
exit (-2); // Database setup error
}
// Everything's OK so far, now store the result in a row
Q_Row = mysql_fetch_row(Q_Res);
//this bit is just for a test
//cout << "ID should be: " << Q_Row[0] << endl;
temp = Q_Row[1];
if(temp == "active")
{
//for now just print confirmation
//cout << "Account Status: Active" << endl;
}
else if(Q_Row[1] == "inactive")
{
cout << "Acount Status: Inactive" << endl;
}
else if(Q_Row[1] == "banned")
{
cout << "Account Status: Banned" << endl;
}
else
{
cout << "Bollox, Error: " << Q_Row[1] << endl;
}
}
mysql_free_result(Q_Res);
mysql_close(conn);
}
I know some it is messy and probably newbish but I'm still learning, any help would be appreiciated :)
