[RESOLVED] why overflow error on WinMe ?

[sergelac]

Private Const WaitTime = 150
 
Private Declare Sub Sleep Lib "kernel32.dll" (ByVal dwMilliseconds As Long)
 
Private Declare Function GetTickCount Lib "winmm.dll" Alias "timeGetTime" () As Currency
Private Const TC As Long = 10000
 
Public Sub Wait(ByVal dwMilliseconds As Long)
  Dim i As Long, zz As Currency
  If dwMilliseconds = 0 Then Exit Sub
  i = dwMilliseconds
  zz = GetTickCount * TC
  Do
    Sleep WaitTime
    i = i - WaitTime
    DoEvents
  Loop Until (i < (WaitTime / 2)) And (((GetTickCount * TC) - zz) >= dwMilliseconds)
End Sub

on a P4 with WinXP : work fine
on a Celeron 600 with Win2K : work fine
on a P3 with WinMe : overflow error

why i get overflow error on WinMe ?

[penagate]

Why oh why are you using timeGetTime()? Use the real GetTickCount().

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

[Keithuk]

You'll get an Overflow error because your API call is wrong.

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

It returns a Long not Currency.

[penagate]

You'll get an Overflow error because your API call is wrong.

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

It returns a Long not Currency.

Do my eyes deceive me, or is that not exactly what I posted...?

Although, you are correct about timeGetTime() returning a Long.

[techgnome]

Do my eyes deceive me, or is that not exactly what I posted...?

Although, you are correct about timeGetTime() returning a Long.

You posted right.... it was the OP that had currency as the return type.

-tg

[sergelac]

http://msdn.microsoft.com/library/de...imegettime.asp

DWORD timeGetTime(VOID);

The return value wraps around to 0 every 2^32 milliseconds

but there is no unsigned type in vb, so i have to use currency
(5 PC we will probably never reboot them and i dont want negative value)

[Keithuk]

Do my eyes deceive me, or is that not exactly what I posted...?

I know you posted that but you didn't say why he would received an Overflow error.

but there is no unsigned type in vb, so i have to use currency

But there is a signed type Long.

[sergelac]

found a solution : no currency and no negative value

You can use another method which simply shifts the number of ticks right by one. Then the number is always positive. You also get away from the 64 bit math.

'Private Const WAITTIME As Long = 150
 
'Private Declare Sub Sleep Lib "kernel32.dll" (ByVal dwMilliseconds As Long)
Private Declare Function timeGetTime Lib "winmm.dll" () As Long
 
Public Sub Wait(ByVal dwMilliseconds As Long)
  Dim z As Long, zz As Long ', i As Long
  If dwMilliseconds < 5 Then Exit Sub
'  i = dwMilliseconds
  dwMilliseconds = dwMilliseconds \ 2
  z = ((timeGetTime And &HFFFFFFFE) \ 2) And &H7FFFFFFF
  Do
'    Sleep2 WaitTime
'    i = i - WaitTime
    DoEvents
'    If i < (WaitTime / 2) Then
      zz = ((timeGetTime And &HFFFFFFFE) \ 2) And &H7FFFFFFF
      If ((zz - z) >= dwMilliseconds) Or (zz < z) Then Exit Do
'    End If
  Loop
End Sub