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X-Tools · Posted: Wed Mar 10, 2004 8:50 am Post subject: Sharing Data between Applications

Hi,

I am looking for a new way to share data between applications.
At the moment I use vdsmem.dll, but it has a bug if too many data is written into the memory. I reduced the data but on some systems with low physical ram the dll crashes with error 27 when I try to receive data from the memorymap.

I need data sharing and notification on data change (like the memorymapchanged event). Reading from registry or inifile at specific times it to unsecure for me (data manipulation by the user).

Thanks for your help.

Bye, Fabian

Skit3000 · Posted: Wed Mar 10, 2004 9:57 am Post subject:

Maybe it's possible to do such a thing?

Server:

Mac · Posted: Wed Mar 10, 2004 10:09 am Post subject:

Skit, I think those addresses are prolly relative to each app's
location in memory, and not global... Confused

I have not used this much, but how about DDE?

Cheers, Mac Smile

X-Tools · Posted: Wed Mar 10, 2004 10:11 am Post subject:

Hi,

adjust seems not to return the value of a variable. Only the memory adress adjusted.

X-Tools · Posted: Wed Mar 10, 2004 10:17 am Post subject:

Hi,

DDE has some problems I reported in some threads before: here

CodeScript · Posted: Wed Mar 10, 2004 10:33 am Post subject:

Yeah skit those (@ADDR() ) are local to the app.

I think since winows 98 data sharing between the apps has become more the feild of COM and as of now there is no access to such a interface in VDS.

Mac · Posted: Wed Mar 10, 2004 10:34 am Post subject:

I checked your link Fabian, and see you found that "the problem
only happens, when you use the WAIT parameter for the RUN
command". Wink

I would guess the problem is that "WAIT" halts the script until
the run command is finished, and this halting interferes with
the still active DDE communication. So DDE may not be at
fault on that, but I'm not sure. Confused

Instead of using "WAIT", you might run a loop after the "RUN"
command to check that "RUN" has finished (the app has closed).

Just a thought. Wink

Cheers, Mac Smile

X-Tools · Posted: Thu Mar 11, 2004 7:54 am Post subject:

thanks for your help. I will play a little bit with DDE again Laughing

X-Tools · Posted: Thu Mar 11, 2004 11:26 am Post subject:

is there a way to prevent the dde link command from starting the dde server app ? My intranet application has several exe files in different folders, but the main apps are in the same folder. all "child apps" shall communicate with the main app. So if dde starts the main app each time if will have much instances of the main app.

Protected · Posted: Fri Mar 12, 2004 9:46 am Post subject:

Perhaps if you close them before the dialog shows? := Or you mean you want the link to be sent to the already open window?

If that's the case, maybe it would be possible to make the server application check if another instance is already open using class names, and, if so, it would pass the information to it and close itself (before dialog creation).

X-Tools · Posted: Mon Mar 15, 2004 6:14 pm Post subject:

I think the vds5 dde functionality is not good enough for this. Sometimes the "child" starts the dde server exe again - also if it is already started. But sometimes not. I don't know why.

I like prakash's vdsdde.dll because I can disallow dde poke there, but it has no "client" functionality.

I found a problem - the client app hangs sometimes on linking to the mainapp like already described in another thread on this board.

PGWARE · **Web Host** Joined: 29 Dec 2001 Posts: 1566

How about using TCP (tcp/ip - internet) on the local computer. Set up one application to be the TCP server, all other app's are the TCP clients. This is simply just using the protocol on the local computer, no internet access is required.

This allows you fast reliable communication with unlimited amounts of data being passed back and forth.

Connection would use > LOCALHOST as the server/host name and the PORT number specified in the script.

You can prevent remote computers from connecting by simply checking client IP connections and check to see if they do not match the localhost ip address, if so deny actions and also remove the user from the client pool.

Protected · Posted: Tue Mar 16, 2004 12:47 pm Post subject:

Oh, that's a great solution :=

X-Tools · Posted: Tue Mar 16, 2004 1:09 pm Post subject:

Hi Prakash,

I already thought about this.
I need more than 10 sub-applications to talk with each other (bidirectional) - so I would have to open too much ports and send notifications to each app.
With memorymap all apps get knowledge.

Maybe gadget.dll can do something like memorymap. I already asked Johnny.

Bye, Fabian

PGWARE · **Web Host** Joined: 29 Dec 2001 Posts: 1566

That's not entirely true.

With TCP you open one port. For instance >>

The TCP Server opens port 352

All TCP Clients also open port 352 to talk to the server.

Now when the server needs to talk to all users it can either send each a notification, (with vdsipp you can use TCP-SERVER SENDALL to instantly send a message to all connected clients).

It's really not as hard as it sounds and is much more reliable then writing/reading memory streams.