Help with singleton patern!!(pool management project)

[KivraS]

Hello there and nice to meet you all!!!I just registered in your forum.And i intend to be an active user.
I am a 22 yo University student from greece!


I was assigned to develop a PoolManagement library for a lesson in c++
The programm supose to open a X number of connections in a database
and handle them to the main programm( multiple connection asked by threads) for doing general use cases as insert update etc etc.

The problem i have (well the most annoying of many many others)
was when i tryied to aplly the singleton patern to the poolManager class
So there can be only one class for a single database

I made a map<> to store all pool managers for diferent databases
Well after doiing so i had tones of errors!! When i solved them another 25 errors apeared.......and became an error labyrinth!!!

I upoloaded the project on rapidshare if someone wants to check it
Its a visual studio 2008 file.

rapidshare.com/files/242455885/DB_poolManager_exception_.rar

I am in a desperate condition i have a week to deliver the project
and i will not pass the lesson if i dont do so! HELPP!!!!


else the code is


MAIN function

// conDB.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include "poolManager.h"
#include "dataHandler.h"
#include <conio.h>
#include <stdio.h>
#include <iostream>
#include <process.h>
#include <windows.h>
#include <vector>
using namespace std;

int main()
{
	//_RecordsetPtr pointerRec;
	//_bstr_t stringConn;
	//poolManager *pool;
	//pool=poolManager::getInstance("ena");
	int epil=0;
	string database;
	map<string,Handler*> handlers;
	vector<HANDLE> threads;

	cout<<"1-Eisagogi dedomenon";
	cout<<"2-Anagnosi dedomenon";
	
	switch(epil)
	{	
	case 1:
	cout<<"dose vasi dedomenon";
	getline(cin,database);
	if (handlers.find(database) == false)
	{
		handlers[database]= new Handler(database);
	}
	

	break;
	case 2:
	cout<<"dose vasi dedomenon:";
	getline(cin,database);
	break;
	default:
	cout<<"lathos epilogi";
	break;
	}


	
	


}

class poolmanager .H

#ifndef POOLMANAGER_H
#define POOLMANAGER_H
#include "stdafx.h"
#include <iostream>
#include <process.h>
#include <windows.h>
#include <map>
#import "c:\Program Files\Common Files\System\ado\msado15.dll" \
	no_namespace rename("EOF", "EndOfFile")
#include <conio.h>
#include <stdio.h>
#include <string>
#include "Connection.h"
const int N=3;
using namespace std;

class poolManager
{
	public:
		
		
		static poolManager* getInstance(string name);
		~poolManager();
		void createConnections(_RecordsetPtr pRst, _bstr_t strCnn);
		class ConnectionCl giveConnection();
		void getStats();
		void returnConnection(class ConnectionCl a);
		
	private:
		
		poolManager(string dbName);
			static map<string,poolManager*> pm;
		string dbName;
		ConnectionCl ConTable[N];
		int openedConnections;
		int freeConnections;
		bool connectionFree;
		bool isFree[N];
		CRITICAL_SECTION crit;
		

};

#endif

Class pool manager cpp

#include "stdafx.h"
#include <iostream>
#include <conio.h>
#include <stdio.h>
#include <vector>

#include "poolManager.h"


using namespace std;


poolManager* poolManager::getInstance(string name)
{
	if( pm.find(name)==false)
	{
		poolManager *poolM = new poolManager(name);
		pm[name]=poolM;
		
	}
	return pm[name];

	}

poolManager::poolManager(string name)
{	
	InitializeCriticalSection(&crit);
	int i;
	dbName=name;
	connectionFree=true;
	openedConnections=0;
	freeConnections=N;
	for(i=0;i<N;i++)
	{
		isFree[i]=true;
		ConTable[N].create(name);
		ConTable[N].setIndex(N);
	}
	cout<<"Etrekse o constructor"<<endl;
}

poolManager::~poolManager()
{
	DeleteCriticalSection(&crit);
}




void poolManager::createConnections(_RecordsetPtr pRst, _bstr_t strCnn)
{

	



}


void poolManager::returnConnection(class ConnectionCl a)
{
		int tmpIndex;
		tmpIndex=a.getIndex();
		isFree[tmpIndex]=true;
		freeConnections++;

}

void poolManager::getStats()
{

	cout<<"oi eleftheres sindeseis einai"<<freeConnections;


}

ConnectionCl poolManager::giveConnection()
{

	int FreeConIndex=0;
	bool found=false;
	while((found==false)&&(FreeConIndex<N))
	{
		if(isFree[FreeConIndex]==true)
		{
			found =true;
			isFree[FreeConIndex]=false;
			freeConnections--;
		}
		else
		{
			FreeConIndex++;
		}
	}
	if(found==true)
	return ConTable[FreeConIndex];
	//else
	//Epistrofi error

}

[dargueta]

For those of us who don't have Visual Studio - what errors exactly are you getting?

[KivraS]

Well the errors are these.....
When i formed the singleton patern they apeared!

------ Build started: Project: DB_poolManager, Configuration: Debug Win32 ------
Compiling...
poolManager.cpp
c:\documents and settings\kivras\desktop\db_poolmanager(exception)\poolmanager.cpp(25) : error C2275: 'std::string' : illegal use of this type as an expression
        c:\program files\microsoft visual studio 9.0\vc\include\xstring(2210) : see declaration of 'std::string'
c:\documents and settings\kivras\desktop\db_poolmanager(exception)\poolmanager.cpp(25) : error C2146: syntax error : missing ')' before identifier 'name'
c:\documents and settings\kivras\desktop\db_poolmanager(exception)\poolmanager.cpp(25) : error C2059: syntax error : ')'
c:\documents and settings\kivras\desktop\db_poolmanager(exception)\poolmanager.cpp(26) : error C2143: syntax error : missing ';' before '{'
c:\documents and settings\kivras\desktop\db_poolmanager(exception)\poolmanager.cpp(28) : error C2597: illegal reference to non-static member 'poolManager::dbName'
c:\documents and settings\kivras\desktop\db_poolmanager(exception)\poolmanager.cpp(29) : error C2597: illegal reference to non-static member 'poolManager::connectionFree'
c:\documents and settings\kivras\desktop\db_poolmanager(exception)\poolmanager.cpp(30) : error C2597: illegal reference to non-static member 'poolManager::openedConnections'
c:\documents and settings\kivras\desktop\db_poolmanager(exception)\poolmanager.cpp(31) : error C2597: illegal reference to non-static member 'poolManager::freeConnections'
c:\documents and settings\kivras\desktop\db_poolmanager(exception)\poolmanager.cpp(34) : error C2597: illegal reference to non-static member 'poolManager::isFree'
c:\documents and settings\kivras\desktop\db_poolmanager(exception)\poolmanager.cpp(34) : error C3867: 'poolManager::isFree': function call missing argument list; use '&poolManager::isFree' to create a pointer to member
c:\documents and settings\kivras\desktop\db_poolmanager(exception)\poolmanager.cpp(34) : error C2109: subscript requires array or pointer type
c:\documents and settings\kivras\desktop\db_poolmanager(exception)\poolmanager.cpp(35) : error C2597: illegal reference to non-static member 'poolManager::ConTable'
c:\documents and settings\kivras\desktop\db_poolmanager(exception)\poolmanager.cpp(35) : error C3867: 'poolManager::ConTable': function call missing argument list; use '&poolManager::ConTable' to create a pointer to member
c:\documents and settings\kivras\desktop\db_poolmanager(exception)\poolmanager.cpp(35) : error C2109: subscript requires array or pointer type
c:\documents and settings\kivras\desktop\db_poolmanager(exception)\poolmanager.cpp(35) : error C2228: left of '.create' must have class/struct/union
c:\documents and settings\kivras\desktop\db_poolmanager(exception)\poolmanager.cpp(36) : error C2597: illegal reference to non-static member 'poolManager::ConTable'
c:\documents and settings\kivras\desktop\db_poolmanager(exception)\poolmanager.cpp(36) : error C3867: 'poolManager::ConTable': function call missing argument list; use '&poolManager::ConTable' to create a pointer to member
c:\documents and settings\kivras\desktop\db_poolmanager(exception)\poolmanager.cpp(36) : error C2109: subscript requires array or pointer type
c:\documents and settings\kivras\desktop\db_poolmanager(exception)\poolmanager.cpp(36) : error C2228: left of '.setIndex' must have class/struct/union
c:\documents and settings\kivras\desktop\db_poolmanager(exception)\poolmanager.cpp(41) : error C2352: 'poolManager::~poolManager' : illegal call of non-static member function
        c:\documents and settings\kivras\desktop\db_poolmanager(exception)\poolmanager.h(21) : see declaration of 'poolManager::~poolManager'
c:\documents and settings\kivras\desktop\db_poolmanager(exception)\poolmanager.cpp(42) : error C2143: syntax error : missing ';' before '{'
c:\documents and settings\kivras\desktop\db_poolmanager(exception)\poolmanager.cpp(50) : error C2601: 'poolManager::createConnections' : local function definitions are illegal
        c:\documents and settings\kivras\desktop\db_poolmanager(exception)\poolmanager.cpp(16): this line contains a '{' which has not yet been matched
c:\documents and settings\kivras\desktop\db_poolmanager(exception)\poolmanager.cpp(60) : error C2601: 'poolManager::returnConnection' : local function definitions are illegal
        c:\documents and settings\kivras\desktop\db_poolmanager(exception)\poolmanager.cpp(16): this line contains a '{' which has not yet been matched
c:\documents and settings\kivras\desktop\db_poolmanager(exception)\poolmanager.cpp(69) : error C2601: 'poolManager::getStats' : local function definitions are illegal
        c:\documents and settings\kivras\desktop\db_poolmanager(exception)\poolmanager.cpp(16): this line contains a '{' which has not yet been matched
c:\documents and settings\kivras\desktop\db_poolmanager(exception)\poolmanager.cpp(77) : error C2601: 'poolManager::giveConnection' : local function definitions are illegal
        c:\documents and settings\kivras\desktop\db_poolmanager(exception)\poolmanager.cpp(16): this line contains a '{' which has not yet been matched
c:\documents and settings\kivras\desktop\db_poolmanager(exception)\poolmanager.cpp(100) : fatal error C1075: end of file found before the left brace '{' at 'c:\documents and settings\kivras\desktop\db_poolmanager(exception)\poolmanager.cpp(16)' was matched
Build log was saved at "file://c:\Documents and Settings\KivraS\Desktop\DB_poolManager(exception)\Debug\BuildLog.htm"
DB_poolManager - 26 error(s), 0 warning(s)
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

[WingedPanther]

Is there a reason why you made your constructor private? You'll never be able to use it.

[KivraS]

Is there a reason why you made your constructor private? You'll never be able to use it.

Well thats the singleton patern.
I make the constructor private so only the getInstance function can call the constructor after it cheks there isnt any other same class defined

[KivraS]

i just found the silly error caused the other 24!~!
sytax error was.....

But still have this error now

poolManager.obj : error LNK2001: unresolved external symbol "private: static class std::map<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,class poolManager *,struct std::less<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > >,class std::allocator<struct std::pair<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const ,class poolManager *> > > poolManager::pm" (?pm@poolManager@@0V?$map@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@PAVpoolManager@@U?$less@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@2@V?$allocator@U?$pair@$$CBV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@PAVpoolManager@@@std@@@2@@std@@A)
C:\Documents and Settings\KivraS\Desktop\DB_poolManager(exception)\Debug\DB_poolManager.exe : fatal error LNK1120: 1 unresolved externals

[dargueta]

Uuuugly. Could you post the fixed code? I think you're not linking to something you should be. First try cleaning the project; I believe it's Build > Clean Project or something like that. After that try recompiling. If it still gives you the error, let us know.

(Alternatively you defined a function somewhere and forgot to implement it.)

[KivraS]

Uuuugly. Could you post the fixed code? I think you're not linking to something you should be. First try cleaning the project; I believe it's Build > Clean Project or something like that. After that try recompiling. If it still gives you the error, let us know.

(Alternatively you defined a function somewhere and forgot to implement it.)

Ok i updated the code in the fields.
I tryed to clean and rebuild but i get the same error.
The linker error 2001 again....

[KivraS]

The problem solved .
Just to mention


I just needed to declare the map<string,poolManager>
Inside the getInstance function not inside the class!