Hello,
I would like to know whether CTIOS(ver 6.0 onwards) support multithreading.
Basically I would like to use CIL  to write a single application(Agent mode) that can receive  receive all agent data (for different CTIOS servers) that it want to subscribe.
My understanding is in Agent mode, we have One agent per session and we have to create for each session for each agent in Agent mode.





So I need to know whether the CTIOS 60.0 onwards  are thread safe or not.

Thank you david. Just one more question:
Currently we are using CTIOS 7.0. As per your mail, it appears to me that currently you aren't supporting any CTI version below 7.5. So if we try to build any application using CTIOS 7.0, we won't get any technical support and maintenence from CISCO. Am I correct?
Regards,
Basudeb

All CTIOS .NET apps are multithreaded. The CTIOS CIL uses an event based asynchronous model which by its nature executes on a background thread. If you check the example code you must ensure that you switch to the UI thread when responding to an event otherwise your app will throw and exception.

As for "thread safety" the CIL is message based and is in essence a fancy wrapper around a set of GED TCP/IP calls to the CTIOS server. As such the CIL per se does not really manage much state in that any state it does maintain is ultimately rectified by the CTIOS server. So while you may maintain a reference to a CTIOS object its really just a wrapper to hold state for essentially what is connectionless/connected model. Bottom line in just about every circumstance the CIL is thread safe.

Unless you have some sort of configuation where the CTIOS servers are non redundant (A/B side) then there is no point to trying to monitor "ALL" servers because only one will be active at time. If the A side server fails then your app should either automatically fail over to the B side ( in Agent Mode ) or you have to add some code to watch for a failure and reinitialize your connection ( in Monitor Mode ). If you try and connect to an inactive server it will simply fail you over to the active one so as I said its kind of pointless.

To maintain muliple sessions you could have a single event processor open the session and dispatch the messages for all sessions which could get messy or you could simply create an even processor for each session and execute the event processor in its own thread, one per session and essentially have multiple silos running in parallell. You could probably even isolate them into their own App Domain if you want even more seperation and process resilency.

It really comes down to what you are trying to achieve and your post is not descriptive enough of your end goal to make an finer detailed assesment. The bottom line is the .NET is fully capable of doing any kind of design you want and the model that the CIL uses lends itself to being used in multiple different ways without too many limitations. The key will be in understanding how to properly mulithread in .NET and using the proper design patterns to achieve your goal. This is generally a far more limiting factor than the CIL is.