Solved

Real-time timer

Posted on 2001-08-06
7
629 Views
Last Modified: 2010-04-06
I need a better timer than the TTimer component. I know there is no perfect timer under Windows 95, but what the TTimer does is quite unacceptable. (The TTimer gives on a 100 MHz Pentium, with the timer interval set to 1,  about 24 timer events per sec -- instead of 1000! Note that the test application was 'honest', doing nothing else in the OnTimer event handler than incrementing a counter.)

I have had the followings ideas.

1. Modifying the priority of the main thread, with the following code in the OnCreate method of the main form:

  mythread:=GetCurrentThread;
  SetThreadPriority(mythread,THREAD_PRIORITY_TIME_CRITICAL);

It makes ABSOLUTELY no difference.


2. Using the SetTimer API function with callback function instead of message posting. I haven't tried it, because the Win32 help says the following:

"When you specify a TimerProc callback function, the DispatchMessage function simply calls the callback function instead of the window procedure. Therefore, you need to dispatch messages in the calling thread, even when you use TimerProc instead of processing WM_TIMER."

So I have the feeling that it won't help me either.


3. Using a driver-level IRQ callback function.

I'm able to handle the IRQ interrupts under Delphi, using an external VxD which can call my Delphi code as callback function when an interrupt arrives, but I don't know whether the timer works with IRQ, and if so, what IRQ should I handle; I'm also not sure that the Windows 95 will share this IRQ with my VxD.


Waiting for ideas and comments,
Adam
0
Comment
Question by:biroadam
7 Comments
 
LVL 3

Accepted Solution

by:
tongalite earned 200 total points
ID: 6354998
Hi,
There are some timer comps about, I have a couple which I downloaded... a multimedia timer and a threaded timer (supposed to be very accurate to within 1 millisecond) that's supposed to do what you require. Untested yet though by me... Can't remember where I downloaded them but if you leave a temp e_mail address I will send them to you if you want.
have fun!
T.
0
 

Author Comment

by:biroadam
ID: 6355106
Hi tongalite!

Sounds pretty good!
My e-mail address is biroadam@softhome.net, I'm waiting for the components.

Best regards,
Adam
0
 
LVL 27

Expert Comment

by:kretzschmar
ID: 6355168
get this sample from simonet

entitled

How To Create High Precision Timers (Multimedia timers)
This project is aimed towards those that think Delphi's TTimer is not precise enought. The solution for that is to create a much more precise and reliable timer, a multimedia timer. This how-to project will teach you how to work with them and discuss when to use a multimedia timer and when to use a system timer (TTimer).  


http://www.bhnet.com.br/~simonet/archive/mmtimer.zip
0
Better Security Awareness With Threat Intelligence

See how one of the leading financial services organizations uses Recorded Future as part of a holistic threat intelligence program to promote security awareness and proactively and efficiently identify threats.

 
LVL 22

Expert Comment

by:mnasman
ID: 6355428
Hello

  you can find alot types of timers at torry site, and most of them free

http://www.torry.net/timers.htm

0
 

Author Comment

by:biroadam
ID: 6355586
Hi everybody!

The problem is actually very simple, there are two Windows API functions designed especially for realtime (multimedia) applications, called TimeSetEvent and a TimeKillEvent.

These functions work with a callback function rather than windows messages, and so they are quite accurate.

Actually I realised this reading the sample sent by kretzschmar, however the question is locked by tongalite.
Since I guess tongalite's answer is also correct (but I haven't received the components yet), I'll wait for it.

Thanks to everybody,
Adam
0
 
LVL 3

Expert Comment

by:tongalite
ID: 6356687
Sorry guys.... (and gals) Must have hit the proposed answer button when all I intended was to make a comment. I'll try not to let that happen again.

Adam,
The comps have been mailed.... Hope they are of use to you.
T.
0
 

Author Comment

by:biroadam
ID: 6356834
Hi tongalite,

As I was sure, your answer was as well as the others. There was only a TIMING problem...

Thank you again,
Adam
0

Featured Post

How your wiki can always stay up-to-date

Quip doubles as a “living” wiki and a project management tool that evolves with your organization. As you finish projects in Quip, the work remains, easily accessible to all team members, new and old.
- Increase transparency
- Onboard new hires faster
- Access from mobile/offline

Join & Write a Comment

Have you ever had your Delphi form/application just hanging while waiting for data to load? This is the article to read if you want to learn some things about adding threads for data loading in the background. First, I'll setup a general applica…
Introduction Raise your hands if you were as upset with FireMonkey as I was when I discovered that there was no TListview.  I use TListView in almost all of my applications I've written, and I was not going to compromise by resorting to TStringGrid…
Illustrator's Shape Builder tool will let you combine shapes visually and interactively. This video shows the Mac version, but the tool works the same way in Windows. To follow along with this video, you can draw your own shapes or download the file…
This video shows how to remove a single email address from the Outlook 2010 Auto Suggestion memory. NOTE: For Outlook 2016 and 2013 perform the exact same steps. Open a new email: Click the New email button in Outlook. Start typing the address: …

708 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

17 Experts available now in Live!

Get 1:1 Help Now