Newbi: Ansynchron Function Call

[Gregor Horvath]

Hi,

I would like to call a PB Function from an VB Application.
The VB aplication should carry on with its work, and the PB function should run parallel.
The VB app calls then a PB stop function, and the previosly started PB function should come to an end.
Symbolic Example:

VB Code:
Sub Main()
....
PBDoSomething 'Ansync call to the PB Function
.....
.....
PBStopWithDoSomething
End Sub()

PB Code:

Private Stop As Boolean

Sub PBDoSomething()
Do
....
Loop Until Stop
End Sub

Sub PBStopWithDoSomething()
Stop = True
End Sub


Is this possible???

Greg

------------------

[Gregery D Engle]

Greg,

Here is some basic PB and VB code for you. To fully understand
everything you need to first do some reading on THREAD CREATE
and do some side reading on CRITICAL_SECTION on MSDN. In any
case here it is.

PBDLL CODE

#COMPILE DLL "C:\TEST.DLL"
#INCLUDE "win32api.inc"
GLOBAL LStop&

FUNCTION DoSomething(x AS LONG) AS LONG
    OPEN "C:\APP.LOG" FOR APPEND AS #1
    WHILE lStop& = %FALSE
        PRINT #1, DATE$ & " " & TIME$ & " TEST!"
    WEND
    CLOSE #1
END FUNCTION

FUNCTION PBDoSomething() EXPORT AS LONG
   THREAD CREATE DoSomething(0) TO woot&
END FUNCTION

FUNCTION PBStopDoSomething() EXPORT AS LONG
   lStop& = %TRUE
END FUNCTION

VB Declares

Declare Sub PBDoSomething Lib "C:\TEST.DLL" Alias "PBDOSOMETHING" ()
Declare Sub PBStopDoSomething Lib "C:\TEST.DLL" Alias "PBSTOPDOSOMETHING" ()

Almost forgot, take a look at the Alias statement in PB. By default all
function names that are exported are in UPPER Case, you can use the
alias statement in PB to change that.

To make this example fully thread safe you need to add
InitializeCriticalSection around Global/Static variables. Sorry
I have to jet to work.

Hope that helps.

------------------
-Greg



[This message has been edited by Gregery D Engle (edited October 16, 2001).]

[Lance Edmonds]

Gregor, to add to Gregery's post, you may also wish to investigate the article on using PB to create multithreaded VB applications...

Multithreading Article for PB and VB: http://www.powerbasic.com/support/te...threading3.asp


------------------
Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>