Managed C++/CLI

Re: which is the best method to send data to clients, without a request from client

12-Feb-09 4:41

naveen_bij wrote:
which is the best method to send data to clients, without a request from client

If the clients are not going to make a request then they have to listen or poll for the data. It's not the best method, it's the only method left after you eliminate requesting data. Essentially there is little difference between the two.

naveen_bij12-Feb-09 18:05

Re: which is the best method to send data to clients, without a request from client

12-Feb-09 18:05

thanks for your response.
so i have to write a listener event in my application. Currently i don't know how to do it, but will try to do that and if any problems will get back for your help

Naveen

Luc Pattyn12-Feb-09 4:47

Luc Pattyn

12-Feb-09 4:47

Hi,

I wouldn't try and push the data from server to client; just have one of these:
- have the client ask whether new admin data is available at the start of a new session;
- or have the server respond with a specific error code rather than real data whenever it feels the
client should get new admin data first.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

- before you ask a question here, search CodeProject, then Google
- the quality and detail of your question reflects on the effectiveness of the help you are likely to get
- use the code block button (PRE tags) to preserve formatting when showing multi-line code snippets

Re: which is the best method to send data to clients, without a request from client

naveen_bij12-Feb-09 18:31

Re: which is the best method to send data to clients, without a request from client

12-Feb-09 18:31

thank you sir,
i thought of using UDP multicasting, where all the clients join a group and server sends a datagram to that group. so i will send a error code to the group stating that new settings are available, when the user modules receive this message they have to complete and stop all the other processes and get the new settings, because the settings are used in other processes.
can u please guide me how to do it in a better way

Naveen

Luc Pattyn13-Feb-09 9:00

Luc Pattyn

13-Feb-09 9:00

Hi,

there are some problems with multicast:
- the sender does not know how many listeners there are
- the sender does not expect a response
- the receivers have no way to respond, to inform things went well, or wrong...
- the receivers may have missed it (being off, or just not listening); if so, no one notices.

So if it is essential that your clients immediately switch over to the new settings, I don't think multicasts are an option. I suggest you close the existing connections (maybe by returning an error on all requests other than CONNECT) and tell the clients that try and
(re)connect that new settings are available.

An easy way to manage versions/settings/... is by adding one byte to every message sent by clients, I would call it the generation number. The server would then refuse all requests with a bad generation number except "give me valid settings", and return an error saying "bad generation"; the client would then close the connection, ask for the latest settings (which works outside a session, and no matter what the generation number is), then
start a new session. And of course every time the server has new settings it simply increments the generation number.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

Re: which is the best method to send data to clients, without a request from client

tyr200023-Feb-09 1:20

tyr2000

23-Feb-09 1:20

why do you eliminate the requesting from client?
what about setting a listening thread on the client which gathering the update command from the admin module?
I am developing a application ,i use this way.

Re: which is the best method to send data to clients, without a request from client

naveen_bij23-Feb-09 20:09

Re: which is the best method to send data to clients, without a request from client

23-Feb-09 20:09

i am eliminating the request from client because the settings changed on the server should be updated immediately to all the clients.
can you please guide me how to write a listening thread, it would be very helpful and how to send the update command to all the clients.
in my application clients are independently running they they take only the settings from server and nothing else. we thought of doing this because server downloads the new settings from another host and then will distribute the settings locally on LAN.

Naveen

tyr200025-Feb-09 1:21

tyr2000

25-Feb-09 1:21

in client modual,I start a thread by createthread(),
in the thread fuction,i use blocked socket api,accept(). and make the thread always runing by while(1).
like below:

while(1)
{
....
accept(); //thread will be blocked here ,i think it's efficient,no more
// cpu time
....
}

in the admin modual, when you want to send changes,using the connect()and send().
do I make myself clear for you?
if not ,I sorry. because english is not my mother language.
if any question more ,we can discuss more.

Re: which is the best method to send data to clients, without a request from client

naveen_bij25-Feb-09 3:53

Re: which is the best method to send data to clients, without a request from client [modified]

25-Feb-09 3:53

thank you for your precious time
it means all my user modules should be connected to admin module and wait in an infinite loop.
what method shall i use to connect to the admin module.
i think my list of questions is growing. since i have recently started working on .net, i dont know much about .net

Naveen

tyr200025-Feb-09 13:07

tyr2000

25-Feb-09 13:07

.net i am not familiar. my project is vc++6.0. so i use blocked socket api.on my admin module,i start a thread for listening client(infinite loop),when client connected successfully,admin module start another thread to dealling with the data transfer.
hope my method can help you.

modified on Wednesday, February 25, 2009 7:51 PM

Re: which is the best method to send data to clients, without a request from client

naveen_bij28-Feb-09 23:01

Assenbly referencing problem

28-Feb-09 23:01

thank you
i will try to work it out as u have said. will get back if any problems

Naveen

KASR111-Feb-09 19:00

KASR1

11-Feb-09 19:00

I am new to C++/CLI.
Tried to reference a dll from VC++ project with Common Language Runtime Support (/clr).

I am getting the below error message when running application.

"An unhandled exception of type 'System.TypeInitializationException' occurred in Unknown Module."

What could be the problem?

led mike12-Feb-09 4:29

12-Feb-09 4:29

KASR1 wrote:
I am new to C++/CLI.

What else are you new to, programming?

KASR1 wrote:
"An unhandled exception of type 'System.TypeInitializationException' occurred in Unknown Module."

What could be the problem?

Yes indeed, what could be the problem, try clicking on this link[^]

KASR112-Feb-09 18:25

KASR1

12-Feb-09 18:25

Are you making fun!
I have tried searching Google and most of them were not specific to my problem.
So we posted it here.

For getting quick solution only we are posting here. Not to make fun!

Kindly give us the solution if you know or dont post a reply like this!

led mike13-Feb-09 5:35

13-Feb-09 5:35

KASR1 wrote:
Kindly give us the solution if you know

I did. If you are not capable of using the link I provided to solve your problem then you need to listen to this song[^]

KASR1 wrote:
or dont post a reply like this!

I will post anything I want asswipe, go f*** yourself.

Oh, and have a nice day.

please help me to work folderbrowser dialog in asp.net

KASR115-Feb-09 17:52

KASR1

15-Feb-09 17:52

Who gave MVP to You! Instead they should give you FVP!!
By seeing your reply they regret themselves.

sivasampathkumar10-Feb-09 22:09

sivasampathkumar

10-Feb-09 22:09

I am working on asp.net using c#
I am working on folderbrowserdialog I got an exception

<big>>"Current thread must be set to single thread apartment (STA) mode before OLE calls can be made. Ensure that your Main function has STAThreadAttribute marked on it. This exception is only raised if a debugger is attached to the process."</big>

Re: please help me to work folderbrowser dialog in asp.net

George L. Jackson11-Feb-09 8:11

George L. Jackson

11-Feb-09 8:11

This is the "Managed C++/CLI" forum! Please post this question in the ASP.NET or C# forum.

"We make a living by what we get, we make a life by what we give." --Winston Churchill

Declare an array of structures containing an array into a Form's class.

chaloens10-Feb-09 5:46

chaloens

10-Feb-09 5:46

Hello,

I'm totally new on Managed C++ and I'm creating an VS2005 C++ application on which I need to keep information for logging purposes.

The data I need to store would have been saved in the old days in a structure like this:

struct tDataEntry
{
    unsigned char data[8];
    long id;
    unsigned int length;
    unsigned int flags;
    unsigned long time;
};

Being a newbie on this I immediately started getting compiler errors like "cannot define 'xxx' as a member of managed 'XXX': mixed types are not supported", so I read a little bit about Managed Code, Mixed types, the GC, etc and I searched the web for an example that could help me out but couldn't find it.

I found some articles that were close to my problem where they suggested using templates to embed a native class in a ref class but when I added the extra complexity of the arrays it just didn't work.

Anyway, I need to be able to declare a fixed size tDataEntry array in my Form class so I can fill the elements, format the information, show it, etc.

Any help on this will be appreciated! Smile | :)

Thanks,
Chalo

Re: Declare an array of structures containing an array into a Form's class.

Mark Salsbery10-Feb-09 6:26

Mark Salsbery

10-Feb-09 6:26

chaloens wrote:
I read a little bit about Managed Code

It may help to read a little bit more...

Visual C++: .NET Programming Guide[^]

.NET Framework Programming[^]

For your specific question...

.NET Framework Equivalents to C++ Native Types[^]

array (Visual C++)[^]

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Re: Declare an array of structures containing an array into a Form's class.

led mike10-Feb-09 6:57

C++/CLI Beginner Questions

10-Feb-09 6:57

Mark Salsbery wrote:
It may help to read a little bit more

NO WAY! We write code! We don't need no stinkin readin!

TripShock10-Feb-09 3:07

TripShock

10-Feb-09 3:07

ref class A
{
...
};

int main()
{
A objA;

return 0;
}

I thought we were not supposed to be able to use ref classes that way...only through tracking handles and tracking references. The above code compiles and runs. Could someone please explain it to me?

Re: C++/CLI Beginner Questions

led mike10-Feb-09 4:33