1. Win32Lib Release resources
I know there's a attachCleanup-function where you can attach a cleanup routine,
but that's only called when an error occurs. Is there also a similar function to
attach a routine that is called when the application ends without errors, so that
a library/application can release its resources?
--
tommy online: http://users.pandora.be/tommycarlier
2. Re: Win32Lib Release resources
Hello there,
It's easy to add a cleanup manager to any program.
Keep a list of rid's of your local cleanup routines
and have each one called as the program exits, for
whatever reason. You'll have to find the best
spot in the library to call this as it should get
called no matter how the process decides to end,
barring major catastrophe 
Take a look at WinClass for an idea how to go
about adding it to your library. It's easy
Take care,
Al
And, good luck with your programming!
My bumper sticker: "I brake for LED's"
3. Re: Win32Lib Release resources
Al Getz wrote:
> It's easy to add a cleanup manager to any program.
> Keep a list of rid's of your local cleanup routines
> and have each one called as the program exits, for
> whatever reason. You'll have to find the best
> spot in the library to call this as it should get
> called no matter how the process decides to end,
> barring major catastrophe
> Take a look at WinClass for an idea how to go
> about adding it to your library. It's easy
For an application, it's not hard: just after WinMain(). But for a library, it's
not that easy. I could create a cleanup-procedure and ask the programmer that
uses the library to call that procedure manually (like I do in Win32Dib), but I
want the library to do it automatically.
--
tommy online: http://users.pandora.be/tommycarlier
4. Re: Win32Lib Release resources
On Sat, 12 Jun 2004 04:06:25 -0700, Tommy Carlier
<guest at RapidEuphoria.com> wrote:
>For an application, it's not hard: just after WinMain(). But for a
>library, it's not that easy. I could create a cleanup-procedure and
>ask the programmer that uses the library to call that procedure
>manually (like I do in Win32Dib), but I want the library to do it
>automatically.
Maybe Derek could add something like this (untested) to win32lib:
(or like as not he'll tell me the name of a routine which already does
this, or explain how they should be attached to the w32HClose of the
main window or something else altogether)
sequence finalCleanup finalCleanup={}
global procedure SetFinalCleanup(object rid)
--
-- usage:
-- SetFinalCleanup(routine_id("name")) adds a final handler
-- with no parameters to the list of routines to be called when
-- WinMain terminates.
-- SetFinalCleanup({routine_id("name"),{3,5,7}}) adds a final handler
-- with three parameters (passed the values shown) to the list of
-- routines to be called when WinMain terminates.
-- SetFinalCleanup({-1,routine_id("name")}) removes a final handler.
-- "name" must be a procedure, not a function!
--
if integer(rid) then
finalCleanup=append(finalCleanup,{rid,{}})
else
if rid[1]=-1 then
for i=1 to length(finalCleanup) do
if finalCleanup[i][1]=rid[2] then
finalCleanup=finalCleanup[1..i-1]&
finalCleanup[i+1..length(finalCleanup)]
exit
end if
end for
else
finalCleanup=append(finalCleanup,rid)
end if
end if
end procedure
and at the end of WinMain:
for i=1 to length(finalCleanup) do
call_proc(finalCleanup[i][1],finalCleanup[i][2])
end for
The above should allow several third party libraries to attach and
detach cleanup handlers to WinMain, as well as allow a single library
to attach several copies of a shutdown routine, eg one for each file
open.
Regards,
Pete
PS I did say, but I'll say again, the above is untested, that's
Tommy's job 
PPS you might want a warning if the detach entry cannot be found, or
if rid as passed is -1 (or {-1,-1}).
5. Re: Win32Lib Release resources
Tommy Carlier wrote:
>
> I know there's a attachCleanup-function where you can attach a cleanup
> routine, but
> that's only called when an error occurs. Is there also a similar function to
> attach
> a routine that is called when the application ends without errors, so that a
> library/application
> can release its resources?
Yes there is . Try including this in your library code.
procedure Close_Screen(integer self, integer event, sequence parms)
integer lRealId
lRealId = getSelf()
if lRealId = getId(w32GetMainWindow) then
. . . Clean up code goes here . . .
end if
end procedure
setHandler(Screen, w32HClose, routine_id("Close_Screen"))
Each library (independant or otherwise) can insert this into their
code and expect it to get called when the Main Window is closed. Actually
it gets called whenever ANY window closes, so you have to detect when
it happens for the main window. That's why the getSelf() call is
there.
setHandler() will create a chain of event handlers and call each one of
them when the event occurs.
Note that this will be called prior to any application handler for the
w32HClose event on the Main Window itself.
Hope this helps.
--
Derek Parnell
Melbourne, Australia
6. Re: Win32Lib Release resources
Derek Parnell wrote:
> Each library (independant or otherwise) can insert this into their
> code and expect it to get called when the Main Window is closed. Actually
> it gets called whenever ANY window closes, so you have to detect when
> it happens for the main window. That's why the getSelf() call is
> there.
>
> setHandler() will create a chain of event handlers and call each one of
> them when the event occurs.
>
> Note that this will be called prior to any application handler for the
> w32HClose event on the Main Window itself.
Thank you, but that doesn't really help: if you look at Win32Dib, you have to
call finalizeDib() after you don't need Win32Dib anymore, to release memory
allocated by the library. I've seen people forget this. That's why I want the
library to do it automatically.
If I use your technique, and I use getSelf() to get the window to be closed,
there are 2 problems:
1. The w32HClose-event is called after this event, and it might still use
Win32Dib-routines. finalizeDib() should be called after all bitmaps are removed
(killDib()), preferably after WinMain().
2. The library doesn't know what the main window is, so it can't compare it to
getSelf().
Can't you just call the attachCleanup()-attached routines if the program ends?
That would just do it, and I think it's logical: resources shouldn't only be
released when an error occurs, but also when no error occurs.
--
tommy online: http://users.pandora.be/tommycarlier
7. Re: Win32Lib Release resources
Ok for now, if you need to do stuff after the application has completed but
before it returns to the DOS prompt, code this into your library...
constant LastEvent = {WM_NCDESTROY,0,0,0}
procedure test_for_app_close(integer self, integer event, sequence p)
if equal(p, LastEvent) then
Do_DIB_Cleanup()
end if
end procedure
setHandler(Screen, w32HAfterEvent, routine_id("test_for_app_close"))
In the meantime, I'll add a cleanup hook to the win32lib library for just
this situation.
--
Derek Parnell
Melbourne, Australia
8. Re: Win32Lib Release resources
Derek Parnell wrote:
> Ok for now, if you need to do stuff after the application has completed but
> before it returns to the DOS prompt, code this into your library...
> In the meantime, I'll add a cleanup hook to the win32lib library for just
> this situation.
Thanks a lot. Although you're not getting paid for Win32Lib, you offer a great
support to the users.
--
tommy online: http://users.pandora.be/tommycarlier
