Re: Multi-threaded TCP Server Problem - C# Discussion Boards

24-Jun-09 3:35

hi. I coded a multi threaded TCP Server (using .net 2.0)
and also I coded a client side program.Client side programs are executing on Mobile Devices
When the client number is six or seven a serious problem occurs , The problem is even if a mobile device send a message to server properly (Socket.Send is succesful and then start waiting for the response ) but often the response message does not arrive to client side.I think this is so weird
Is there a concurrent use of server side network i/o or something and needed to thread synchronization
to send data to clients or this is all about wireless network performance

Ennis Ray Lynch, Jr.24-Jun-09 4:05

24-Jun-09 4:05

It is likely a design issue. Multithreaded programming is an Advanced concept (to do correctly) and sockets programming is up there as well. (Compared to ASP.NET) If you have a TCP/IP socket you are guaranteed to be able to get data in order or get an exception (or socket closed).

Need custom software developed? I do C# development and consulting all over the United States.

A man said to the universe:
"Sir I exist!"
"However," replied the universe,
"The fact has not created in me
A sense of obligation."
--Stephen Crane

kordel22224-Jun-09 4:58

24-Jun-09 4:58

but I look at a lot of sample code of multi threaded server applications.I can not find major diffirences to cause this kind of problem.Just I can see about that I don't use asynchronous functions for example networkstream.BeginWrite.
is that ok the concurrent (from all running threads) use of networkstream.Write function
may be somehow some Write functions fails according to concurrent use I don't know really.

Ennis Ray Lynch, Jr.24-Jun-09 5:02

24-Jun-09 5:02

All of the sample code on the web for multi-threaded tcp/ip code is derived from the MS sample which is crap.

kordel22224-Jun-09 5:22

24-Jun-09 5:22

my server code look like this sample code(Concurrent Server Application Example) its url
http://blog.rednael.com/2008/11/07/ParallelComputingWithSockets.aspx

I am not sure it is crap or something else but I can not find any better sample .
But I want to repeat my main problem is clients sometimes does not get response messages from server even if at the first it can send messages server properly
any idea..? thanks a lot

Ennis Ray Lynch, Jr.24-Jun-09 5:27

24-Jun-09 5:27

Back in 1999 I spent 3 days with a packet sniffer to debug a client server application I wrote in C++. How long have you spent analyzing the raw network traffic and your code?

The code is hard to write and isn't usually a one line fix or an, oh you missed this. And like I said previously, all samples on the web derive from the MS sample which is crap including the link you provided which you would have known had you bothered to look at the MS sample.

Crappy MS code that has been plagiarized the Internet over with no real value ever added. [^]

kordel22224-Jun-09 5:50

24-Jun-09 5:50

ok I undestand you all sample codes looks like each other but is there any good one in internet or book to inspire me

led mike24-Jun-09 9:41

led mike

24-Jun-09 9:41

check out sockets.com. I first used it in 1994 or 5

led mike24-Jun-09 4:38

led mike

24-Jun-09 4:38

kordel222 wrote:
I think this is so weird

There is nothing weird about it. Most people will have difficulty properly coding a multithreaded socket server even if they have vast experience doing it. If you are a novice then this is completely normal.

The thing that is actually weird is how many novices believe it will be simple to do it.

kordel22224-Jun-09 8:29

c# windows application......

24-Jun-09 8:29

I don't mean this is a easy subject.indeed this is the hardest programming subject I ever seen
I agree with you.
but still is there not even a clue about my question.

singhdurgesh24-Jun-09 2:47

singhdurgesh

24-Jun-09 2:47

hii..

m creating a c# windows application......

in this i need to complete all my task at the init event of form......and after completeion of work.....i need to completely stop the application

Re: c# windows application......

Gary Stafford24-Jun-09 3:01

Gary Stafford

24-Jun-09 3:01

I would use Application.Exit(); after completing the work, to exit the Form and the application. MSDN: http://msdn.microsoft.com/en-us/library/ms157894.aspx[^]

Regards,

Gary

Use a console application or a Service

Ennis Ray Lynch, Jr.24-Jun-09 3:10

Re: c# windows application......

24-Jun-09 3:10

A console application is ideally suited to performing a task and then exiting. Even the console box can be hidden.

PIEBALDconsult24-Jun-09 4:51

PIEBALDconsult

24-Jun-09 4:51

Well whoopdy-doo.

Update Table

kibromg24-Jun-09 2:13

24-Jun-09 2:13

Hi All,

I have the follwoing data on html page :

"NEW","939192","0005","0108500301000000001"
"NEW","939192","0005","0208500301000000003"

How can i read the above comma separated data on a page and Populate my Table in Sql 2005.

Thank you in Advance.

ScottM124-Jun-09 2:21

ScottM1

24-Jun-09 2:21

Have you tried DTS?

kibromg24-Jun-09 2:35

You can use an insert statement

24-Jun-09 2:35

Thank you so much.Is there not a way of wrting a code to do that?

Ennis Ray Lynch, Jr.24-Jun-09 3:08

Re: You can use an insert statement

24-Jun-09 3:08

That is usually how I insert into SQL. The CSV data can be split using the string.split method and if you parametrize the queries you will avoid SQL injection but still be susceptible to spammers so you will need to HTML encode any input.

kibromg24-Jun-09 4:00

Re: You can use an insert statement

24-Jun-09 4:00

The problem is its not a csv file .The data is posted on a browser.
How could i read data on a browser?

Many thanks,

Ennis Ray Lynch, Jr.24-Jun-09 4:03

Re: You can use an insert statement

24-Jun-09 4:03

It is fairly difficult concept described in the "Beginning ASP.NET 3.5: In C# and VB" book published by Wrox in Chapters:5, 9, 11, and 12.

kibromg24-Jun-09 6:35

24-Jun-09 6:35

Thank you so much.Can you please give me a little more info on how to do that?

Your help is much appreciated.

Many thanks

PIEBALDconsult24-Jun-09 7:09

PIEBALDconsult

24-Jun-09 7:09

Dunno, depends on how the information is presented on the page. One such page I scrape for data has the data I want in a table. The code I use to get the page is:

System.Net.HttpWebRequest req = (System.Net.HttpWebRequest) System.Net.HttpWebRequest.Create ( theurl ) ;
                
req.CachePolicy = new System.Net.Cache.RequestCachePolicy ( System.Net.Cache.RequestCacheLevel.NoCacheNoStore ) ;
 
using ( System.Net.HttpWebResponse rsp = (System.Net.HttpWebResponse) req.GetResponse() )
{
    string res = ( new System.IO.StreamReader ( rsp.GetResponseStream() ) ).ReadToEnd() ;
 
    // Then I use a Regular Expression to extract what I want
    // and insert it to the database.
}

I make no claims that this technique is "good", only that it does what I want for a rather unimportant Windows Service.

kibromg24-Jun-09 11:21