ASM Community

When you wish to pass parameters to a DLL as , you need pass then ByRef, as opposed to ByVal.

The difference is ByVal passes the actual runtime value of a variable, and ByRef passes the address where that value is stored.

Now, once control returns to VB, VB will look at the address where it stores a variable. And that address is what you need change.

Your code would thus look like so:

Testspeed Proc pFtime1:DWORD, pFtime2:DWORD, pFtimeDIFF:DWORD 

   Local Ticks1 :DWORD 

   Local Ticks2 :DWORD 



    Invoke GetTickCount 

    mov Ticks1, eax 

    mov eax, 00h 

    

loop1:

inc eax 

cmp eax, 00FFFFFFh  

jne loop1 



    Invoke GetTickCount 

    mov Ticks2 , eax

    mov ecx, pTicks2          ; gets the ADDRESS of Ftime2

    mov [ecx], eax             ; saves GetTickCount to Ftime2

    mov eax, Ticks1 

    mov ecx, pFtime1         ; gets the ADDRESS of Ftime1

    mov [ecx], eax             ; saves GetTickCount to Ftime1

    mov eax, Ticks2 

    sub Ticks1, eax 

    mov eax, Ticks1 

    mov ecx, pFtimeDIFF    ; gets the ADDRESS of FtimeDIFF

    mov [ecx], eax             ; saves GetTickCount to FtimeDIFF

ret 

Testspeed EndP 

You also must define the dll proto in VB to pass the values ByRef.

Technically, you are calling a Subroutine here, not a function. The difference is a function will return an extra value in eax. VBB then uses that value and assigns it to whatever you assigned it to (with the equals sign).

Subs don't return a value, though in later versions of VB it seems the definitions os Sub and Function have converged to mean the same thing.

Qages,

In your DLLmain, use this

mov eax, 1
ret

If you return zero, the DLL assumes an error and will not load.

Regards,

hutch@movsd.com

Qages,

If you are going to build successful DLLs to call with other languages, do it according to the documentation. Look up "DllEntryPoint" in win32.hlp for more information but at the minimum you should return TRUE (1) in the LibMain/DllMain.

It is normally returned from the "DLL_PROCESS_ATTACH" part when the "fdwReason" parameter is evaluated.

You NEVER call the LibMain/DllMain, the operating system loader does this when it first loads the DLL. The reason for the option at startup is if there is a failure, the load will abort.

Regards,

hutch@movsd.com

i dont have a .data section yet(not using it at the momemnt.) is that why its bloating my exe?
i am returning 1 in eax in both of my procs.
i will post all of my code

    .386

    .model flat, stdcall

    option casemap :none  



    Include ..\masm32\Include\windows.inc

    Include ..\masm32\Include\user32.inc

    Include ..\masm32\Include\kernel32.inc



    IncludeLib ..\masm32\lib\user32.lib

    IncludeLib ..\masm32\lib\kernel32.lib

; #########################################################################

.Code



dllmain Proc xcompielr:DWORD, xdamn:DWORD, xwarning:DWORD

mov eax, 01h

ret

dllmain EndP



Testspeed Proc pFtime1:DWORD, pFtime2:DWORD, pFtimeDIFF:DWORD, pLoopTimes:DWORD

   Local Ticks1 :DWORD 

   Local Ticks2 :DWORD 



    Invoke GetTickCount  

    mov Ticks1, eax 

    mov eax, 00h 

  

loop1:

inc eax 

cmp eax, pLoopTimes

jne loop1 



    Invoke GetTickCount 

    mov ecx, pFtime2          ; gets the ADDRESS of Ftime2

    mov [ecx], eax             ; saves GetTickCount to Ftime2

    sub eax, Ticks1

    mov ecx, pFtimeDIFF    ; gets the ADDRESS of FtimeDIFF

    mov [ecx], eax             ; saves GetTickCount to FtimeDIFF

    mov eax, Ticks1 

    mov ecx, pFtime1         ; gets the ADDRESS of Ftime1

    mov [ecx], eax             ; saves GetTickCount to Ftime1

    mov eax, 01h

ret 

Testspeed EndP 

End dllmain

vb

Private Declare Sub test3bytes Lib "Firstdll.dll" Alias "Testspeed" (ByRef Xtimebeg As Long, ByRef Xtimeend As Long, ByRef Xtimediff As Long, ByVal Xamt As Long)

Private Declare Function GetTickCount Lib "kernel32" () As Long

Private Sub Main()

Dim val1 As Long, val2 As Long, val3 As Long, time1 As Long, time2 As Long, i As Long, b As Long

MsgBox "this test is " & Format(&H7FFFFFFF, "###,###") & " times"

Call test3bytes(val1, val2, val3, &H7FFFFFEF)

MsgBox val3 & " milliseconds to execute a loop adding 1 by one " & &H7FFFFFEF & " times iN ASM!! ~ dont worry if it is slow to show the next box heh"

time1 = GetTickCount

For i = 1 To &H7FFFFFEF

b = b + 1

Next i

time2 = GetTickCount

MsgBox CStr(time2 - time1) & " milliseconds to execute a loop adding 1 by one " & &H7FFFFFEF & " times iN VB!!"

MsgBox "asm times faster " & CStr((time2 - time1) / val3) & " than vb"

End Sub