Solved

threading delphi tptimecritical tpnormal problem hanging application freeze setwaitabletimer

Posted on 2004-09-22
8
872 Views
Last Modified: 2008-01-09
Hi there,

we wrote a Delphi application using multiple threads. One for scanning an hardware component, another one for communicating over TCP/IP and a last one for critical timing. The last one is a component we designed using the SetWaitableTimer API from windows. This function is encapsulated in a thread. When this thread priority is put to TimeCritical, the application works without any problem. If we put it to tpNormal, the application crashes with a huge network load. When we insert logging in the application, it shows that he hangs on a different line of code each time, so it seems that the code isn't wrong and that the threads are messing up something when it is set to tpNormal. Does anyone has tips, tricks, ideas of how to search this error and trap it..... We are already searching for weeks and we are a little bit out of ideas....
0
Comment
Question by:TDDatATS
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
8 Comments
 
LVL 17

Expert Comment

by:Wim ten Brink
ID: 12122325
Timing issue in multiple threads. Nasty. Probably an unprotected resource that gets read and written at the same time. I've had similar problems and they're extremely hard to debug.

The only way I managed to solve such problems was by using a log file and then write as much as possible information to this log file. Every thread it's own log file and every line with a timestamp.
0
 
LVL 4

Expert Comment

by:Colin_Dawson
ID: 12127026
I'd do the same thing.  But I'd go a step futher and use the QueryPerformanceCounter to give the timestamp, not anything that's based on GetTickCount or even worse, dd/mm/yyyy hh:nn:ss.zzz.   Yuck!

Col.
0
 
LVL 4

Expert Comment

by:Colin_Dawson
ID: 12127050
Also I'd spend some time looking through the entire code to see if there's nothing trying to talk across threads.   Even down to the point where all my inter-thread communication is done via the Windows message Queue.

Col.
0
Technology Partners: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

 
LVL 20

Expert Comment

by:Madshi
ID: 12130944
Are you using Delphi threads or win32 threads? In the latter case make sure you've set "IsMultiThread := true". Otherwise the memory manager will crash.

Also madExcept might be worth a try. It's free for non-commercial usage. If your project is commercial, you can use the non-commercial version for evaluation:

http://help.madshi.net/madExcept.htm
http://madshi.net/madCollection.exe
0
 

Accepted Solution

by:
modulo earned 0 total points
ID: 13442893
PAQed with no points refunded (of 250)

modulo
Community Support Moderator
0
 

Author Comment

by:TDDatATS
ID: 13600704
Sorry DanRoillins, Modulo,

I was a little bit busy that period.

Thanks for cleaning up.

Tom.
0

Featured Post

Technology Partners: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Introduction The parallel port is a very commonly known port, it was widely used to connect a printer to the PC, if you look at the back of your computer, for those who don't have newer computers, there will be a port with 25 pins and a small print…
Introduction I have seen many questions in this Delphi topic area where queries in threads are needed or suggested. I know bumped into a similar need. This article will address some of the concepts when dealing with a multithreaded delphi database…
This video Micro Tutorial shows how to password-protect PDF files with free software. Many software products can do this, such as Adobe Acrobat (but not Adobe Reader), Nuance PaperPort, and Nuance Power PDF, but they are not free products. This vide…
If you're a developer or IT admin, you’re probably tasked with managing multiple websites, servers, applications, and levels of security on a daily basis. While this can be extremely time consuming, it can also be frustrating when systems aren't wor…

729 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