Channel Managers

Last time, we left off the channel construction process at the end of the design stage. During the design stage, everything is still in an unmolded and configurable state. At the end of the design stage, the construction process flips from a configuration mode to a runtime mode. The runtime stage has fixed all of the design settings and is in an operational state. Here were the products so far in the construction process starting from the service.

1.
Service 2. Service endpoint 3. Service endpoint contract 4. Service endpoint transfer contract (binding) 5. Binding design settings 6. Realization of binding design settings (binding elements)

From the binding elements we can produce two objects called channel managers. A channel manager is something that can produce communication channels on demand. One type of channel manager is the channel factory. Channel factories create communication channels that initiate a connection or message send. The other type of channel manager is the channel listener. Channel listeners create communication channels in response to a message or connection attempt. Channel factories generally live in client applications and channel listeners generally live in service applications.

The channel manager is the first product in the construction process that performs network operations and can represent a network object. For example, channel managers may contact security servers in preparation for creating communication channels or allocate resources such as a TCP listener socket. The creation of communication channels is controlled by the user for channel factories and essentially controlled by the system for channel listeners. You have to initially start the channel listener but further action is taken in response to messages or connections arriving from other machines.

Communication channels are the conduits for sending and receiving messages. The final product of the construction process is one of these channels. For those of your following along, that means to produce a custom channel you will need to write the binding, the binding element, the channel managers, and the channel. All of these were included in the channel writing checklists (the binding was the only one on the optional checklist).

When we get to the next two articles in the tour series, the coverage will be on writing the binding element and channel managers.

Next time: Responding to GetProperty

Comments

• Anonymous
  March 21, 2007
  We're back to the channel development tour for another pair of articles. Today's article is the first