[fpc-pascal] Please Help - Need ONE HINT - Trying to get

Jason P Sage jasonpsage at jegas.org
Sat Sep 16 15:54:23 CEST 2006

>Jason Sage wrote:
> Hi all - and thanks to who ever can respond in advance.
> I have a Server Like App - I need the equivalent of sched_yield
>Tried sleep(0); yet ?
> Micha

Yes. Sleep has been added where appropriate. I didn't know to try Sleep
ZERO. That sounds better than my Sleep(10). Thank You for that suggestion.

I was trying to avoid sysutils sleep(0) in linux platform due to the size of
sysutils. The fact I don't know how to make dynamic linking work on linux
yet - (use shared libs versus static) makes my exe's bigger than I would
like. In most of my applications, size isn't an issue - but in one in
particular - it is everything. Using shared linking in linux, which I think
is possible, would make for less overhead for the operating system to invoke
each instance of this (ideally) small as possible application. This "small"
app is fired often, simultaneously, and load/execute/terminate time is
critical but needs to yield when its not busy. The YIELDING part works.
Thank You. 

On this note, for size reasons, in win 32 I use the Win32 API call that does
the same thing as sysutils sleep. This is what promprted my question - to
call the operating system (in linux I guess its sched_yield) "sleep"

In another area around CPU yielding - and multithreading....
What I have learned since I wrote this question is that sleep (and
sched_yield) is not an appropriate means to get different "threads" a
timeslice, which was my impression. I THINK that sleep refers to releasing
or yielding your entire application to other tasks the operating system is
handling. Which means its use should be minimal, and strategic - like when
you application true "should" release the CPU a bit... or is "truly" idle.

You see I have been playing with TThread - and I noticed that the most
currently launched thread is the one who stays running - and everything else
in my app stops until it finishes. This leads me to believe I am responsible
for managing what threads runs when - whether timeslices, "loop counters"
inside the thread - (I ran four iterations - you can suspend me again) ...
or some sort of mechanism. I believe TThread.Syncronize and possibly TThread
Critical Section are going to be my next area of experimentation.

Along this lines I have changed the entire "main loop" architecture of my
bigger THREADING application - to work similar to how Lazarus makes its
executables or how a windows program works in win32 - I've built a messaging
system - that is a COMMON construct throughout all my classes, so that they
can ALL communicate in a context-less way to the main program - allowing the
main program to respond by suspending, resuming, terminating... etc any/all
of the working threads as it deems correct.

Thank You For Your Response Micha. Any and all help is always appreciated.

Jason P Sage

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