/*
	Sampledll.dll
	Author : Mithun Shanbhag, mrshanbh@syr.edu
*/

#include <windows.h>
#include <process.h>
#include <iostream>

/* param for TLS storage */

typedef struct 
{ DWORD myId ;
}TLSParam, * pTLSParam ;

/* the key */

static DWORD TLSKey ;

//----< The Thread Proc >----

unsigned __stdcall ThreadFunc (void * p) { return 0 ; } // really does nothing

//----< Dll Entry Point >----

BOOL __stdcall DllMain (HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved)
{
	DWORD thrId = GetCurrentThreadId () ;
	DWORD procId = GetCurrentProcessId () ;
	pTLSParam pThrData ;

	switch ( fdwReason )
	{

	case DLL_PROCESS_ATTACH:

		printf ( "DLL : I am attached to Process # %d \n" , procId ) ;
		DisableThreadLibraryCalls ( GetModuleHandle ( "SampleDll.dll" ) ) ; 
		if ( ( TLSKey = TlsAlloc () ) == TLS_OUT_OF_INDEXES )
		{ printf ( "DLL : No keys available for TLS Indexing\n" ) ;
		  return FALSE ;
		}
		else
          printf ( "DLL : key obtained for TLS Indexing\n" ) ;


		/*	Entry to DllMain () is serialized by some internal synchronization primitive. */

		HANDLE hInternalThread ;
		unsigned InternalThreadId ;

		////////////////////////////////////////////////////////////////
		/* This should generate CREATE_THREAD_DEBUG_EVENT in debugger */
		////////////////////////////////////////////////////////////////

		hInternalThread = (HANDLE) _beginthreadex ( NULL,
													0,
													&ThreadFunc,
													NULL,
													0,
													&InternalThreadId ) ;

		//////////////////////////////////////////////////////////////
		/* This should generate EXIT_THREAD_DEBUG_EVENT in debugger */
		//////////////////////////////////////////////////////////////

		CloseHandle ( hInternalThread ) ;
		break ;
	
	case DLL_THREAD_ATTACH:

		printf ( "DLL : I am attached by thread # %d of process # %d \n" , thrId, procId ) ;
		pThrData = new TLSParam ;
		pThrData -> myId = thrId ;
		if ( TlsSetValue ( TLSKey, pThrData ) != 0 )
			printf ( "DLL : Stored data of thread # %d of process # %d in TLS \n", thrId, procId ) ;
		else 
			printf ( "DLL : Unable to store data of thread # %d of process # %d in TLS \n", thrId, procId ) ;
		break ;
	
	case DLL_THREAD_DETACH:
		printf ( "DLL : I am detached from thread # %d of process # %d \n" , thrId, procId ) ;
		pThrData = ( pTLSParam ) TlsGetValue ( TLSKey ) ;
		if ( pThrData != NULL )
		{	delete pThrData ;
			printf ( "DLL : Removed data of thread # %d of process # %d from TLS \n", thrId, procId ) ;
		}
		else 
			printf ( "DLL : Could not Remove data of thread # %d of process # %d from TLS \n", thrId, procId ) ;
		break ;
	
	case DLL_PROCESS_DETACH:
		printf ( "DLL : I am detached from Process # %d \n" , procId ) ;
		if ( TlsFree ( TLSKey ) != 0 )
			printf ( "DLL : key has been freed\n" ) ;
		else
			printf ( "DLL : key could not be freed\n" ) ;
		break ;
	}

	return TRUE ;
}


extern "C" __declspec (dllexport) void SayHello ( DWORD thrId, DWORD procId )
{
	printf ( "Hello From Thread # %d of Process # %d !\n", thrId, procId ) ;
}

extern "C" __declspec (dllexport) void AnotherDummyExport (  )
{
}