>We have a VB 6 application that calls an ActiveX exe (this ActiveX exe
>has a timer with time interval = 1, so that it right away exits out of the
>ActiveX
>exe and let the main application be free to do other things). The ActiveX
>exe threading model is "Thread per object". The reason for
>the ActiveX exe is to mimick a multi threading process, so that the main
>application can do multiple processes without having to wait for 1 process 
>to finish. Inside the ActiveX exe we do the compression using an ActiveX
>control.
>
>When we just call 1 to 2 of the ActiveX exe, everything works fine,
>but when we call 3 or more of the Activex Exe at the same time to compress
>the file, we get
>the following error:
>
>err = 372 ; error = Failed to load control 'ECLaxX' from ECLActiveX.ocx.
>Your version of ECLActiveX.ocx may be outdated.
>Make sure you are using the version of the control that was provided
>with your application.
>
>Is this because the Activex control that we use to compress the file is not
>multi threaded ?
>How can I fix this problem ?
>Somebody told me to protect my compression section with a semaphore, what
>does it mean and can I do it in VB 6 ?

"J French" wrote:

> On Fri, 27 May 2005 10:00:17 -0700, "=?Utf-8?B?UGF1bCBmcHZ0Mg==?="
> <Paulfp***@discussions.microsoft.com> wrote:
>
> >We have a VB 6 application that calls an ActiveX exe (this ActiveX exe
> >has a timer with time interval = 1, so that it right away exits out of the
> >ActiveX
> >exe and let the main application be free to do other things). The ActiveX
> >exe threading model is "Thread per object". The reason for
> >the ActiveX exe is to mimick a multi threading process, so that the main
> >application can do multiple processes without having to wait for 1 process 
> >to finish. Inside the ActiveX exe we do the compression using an ActiveX
> >control.
> >
> >When we just call 1 to 2 of the ActiveX exe, everything works fine,
> >but when we call 3 or more of the Activex Exe at the same time to compress
> >the file, we get
> >the following error:
> >
> >err = 372 ; error = Failed to load control 'ECLaxX' from ECLActiveX.ocx.
> >Your version of ECLActiveX.ocx may be outdated.
> >Make sure you are using the version of the control that was provided
> >with your application.
> >
> >Is this because the Activex control that we use to compress the file is not
> >multi threaded ?
> >How can I fix this problem ?
> >Somebody told me to protect my compression section with a semaphore, what
> >does it mean and can I do it in VB 6 ?
>
> That sounds very peculiar
> Try launching a number of normal EXEs at the same time, and see what
> happens.
>
> My suspicion is that ECLActiveX.ocx is checking for the number of
> instances of itself - and artificially (deliberately) screwing you up.
>
> IMO semaphores are a red herring.
> Think of semaphores as 'Walk/Don't walk' lights that you can set and
> obey or disobey at will.
>
> One further point, it is often better to queue processor intensive
> jobs - threads are a bit of an illusion, one only has one CPU
> ( or two if one has bought into the bulls**t )
>
>
>

>Thank you for your reply.
>> Try launching a number of normal EXEs at the same time, and see what
>> happens.

>When I put the ECLActiveX.ocx inside a normal EXE, and launch 7 copies of
>the EXE, I did not get the error.
>What does it mean ?
>I can not use a normal EXE, because to eah EXE I need to pass an object,
>which is a class object. If there is a way to pass an object through an EXE,
>I would use a normal EXE, is there a way to do this ?

>> One further point, it is often better to queue processor intensive
>> jobs - threads are a bit of an illusion, one only has one CPU
>> ( or two if one has bought into the bulls**t )

>Unfortunately, I can not do this, because every user will then have to wait
>for another user to finish before the next job can be processed.

"J French" wrote:

> On Tue, 31 May 2005 16:17:52 -0700, "=?Utf-8?B?UGF1bCBmcHZ0Mg==?="
> <Paulfp***@discussions.microsoft.com> wrote:
>
> >Thank you for your reply.
> >> Try launching a number of normal EXEs at the same time, and see what
> >> happens.
>
> >When I put the ECLActiveX.ocx inside a normal EXE, and launch 7 copies of
> >the EXE, I did not get the error.
> >What does it mean ?
> >I can not use a normal EXE, because to eah EXE I need to pass an object,
> >which is a class object. If there is a way to pass an object through an EXE,
> >I would use a normal EXE, is there a way to do this ?
>
> >> One further point, it is often better to queue processor intensive
> >> jobs - threads are a bit of an illusion, one only has one CPU
> >> ( or two if one has bought into the bulls**t )
>
> >Unfortunately, I can not do this, because every user will then have to wait
> >for another user to finish before the next job can be processed.
>
> Fine, so we know that you can have 7 copies of that OCX running at the
> same time in 7 EXEs
>
> Does your AX EXE notify the caller when it is finished ?
> - or is it just 'here is a job - go process it'
>
> How complex is the Object that is being passed over ?
> Could it be written to a file - or is it rather 'interactive'
>
> What type of creation/usage property have you given the exposed Class
> in the AX EXE (Instancing)
> Have you tried setting it to 3 Single Use
>
> My suspicion is that the OCX has the equivalent of a .BAS module
> behind it, and that is being shared by the different
> instances/invocations of the AX EXE
>
> If your AX EXE does not call back to momma when done (or maybe even if
> it does) you could set up a queue of objects to be processed inside
> the AX EXE.
>
> Multiple threading is not all that it is cracked up to be, it is great
> for tasks that are just waiting, but for things that are using the CPU
> intensively it is just wasting time jumping between tasks.
>
> I think that your problem is caused by a shared Data segment buried
> inside the OCX - setting the instancing to Single Use should fix that.
>
>
>

"J French" wrote:

> On Wed, 1 Jun 2005 10:05:20 -0700, "=?Utf-8?B?UGF1bCBmcHZ0Mg==?="
> <Paulfp***@discussions.microsoft.com> wrote:
>
> >Thank you very much for your reply.
> >> Does your AX EXE notify the caller when it is finished ?
> >> - or is it just 'here is a job - go process it'
> >It is just 'here is a job - go process it'. How can ActiveX exe notifies the
> >caller when it is finished?
>
> Easy, you pass a reference to a Class or a Form in the calling EXE
> - down to the AX EXE where it 'remembers' it
>
> Then the AX EXE can call the main EXE using a 'known' Public function
> in the Class or Form
> - note: you'll most likely need to send the Clas or Form as an Object
>
> >> How complex is the Object that is being passed over ?
> >> Could it be written to a file - or is it rather 'interactive'
> >The object is a class object for the Winsock control (which has client
> >connection, etc.), so unfortunately I can not write it to a file.
>
> Gottit
> 
> >> What type of creation/usage property have you given the exposed Class
> >> in the AX EXE (Instancing)
> >> Have you tried setting it to 3 Single Use
> >The AX exe instance was 5-MultiUse.
> >I changed it to 3-Single Use per your advice, and so far it seemed to work
> >fine.
> >If I don't get any more error until tomorrow, I will know for sure it works.
> >I will keep you posted.
>
> I think that will have fixed it
> 5 MultiUse allows the variables in .BAS modules to be shared by all
> the EXEs using the AX EXE
>
> 3 Single Use does not permit this 'sharing', and my bet is that
> something in the OCX was 'sharing' stuff in a concealed .BAS module.
>
> >Thanks a lot for your help.
>
> You are welcome - I hope that your problem is solved
>