'**************************************
' Name: Changing priority
' Description:This code fragment demonst
'     rates how you can get a program to chang
'     e it's own priority.
Sometimes it is necessary To change the priority of a process from the default.
The example that prompted this code was a program I had To launch from a commercial scheduler always defaulted to idle priority. This caused the program to miss it's processing deadline. Increasing the priority to normal or high solved the problem.
' By: Steve Pepper
'
' Assumes:To run this code, add a form t
'     o a new project with a timer and a label
'     .
The priority will toggle between idle and high every two seconds.
Under NT4, you can use the task manager To see the base priority of this process changing.
'
' Side Effects:Changing the priority of 
'     your process to REALTIME_PRIORITY_CLASS 
'     is a bad idea in Visual Basic.
I have only tested this code under NT4 sp4 and VB5 but I think it should work under Windows9x
'
'This code is copyrighted and has' limited warranties.Please see http://w
'     ww.Planet-Source-Code.com/vb/scripts/Sho
'     wCode.asp?txtCodeId=1683&lngWId;=1'for details.'**************************************

Sub ChangePriority(dwPriorityClass As Long)

    Dim hProcess&
    Dim ret&, pid&
    pid = GetCurrentProcessId() ' get my proccess id
    ' get a handle to the process
    hProcess = OpenProcess(PROCESS_DUP_HANDLE, True, pid)
    If hProcess = 0 Then
        Err.Raise 2, "ChangePriority", "Unable To open the source process"
        Exit Sub
    End If

    ' change the priority
    ret = SetPriorityClass(hProcess, dwPriorityClass)
    ' Close the source process handle
    Call CloseHandle(hProcess)
    If ret = 0 Then
        Err.Raise 4, "ChangePriority", "Unable To close source handle"
        Exit Sub
    End If

End Sub


Private Sub Form_Load()

    Timer1.Interval = 2000
    Call Timer1_Timer
End Sub


Private Sub Timer1_Timer()

    Static Priority&
    If Priority = IDLE_PRIORITY_CLASS Then
        Priority = HIGH_PRIORITY_CLASS
        Label1.Caption = "HIGH priority"
    Else
        Label1.Caption = "IDLE priority"
        Priority = IDLE_PRIORITY_CLASS
    End If

    Call ChangePriority(Priority)
End Sub