[5317] Updated Developer's Guide.

src/lib/config/command-socket.dox

@@ -154,39 +154,21 @@ or HTTPS connection):
 - @ref isc::config::CommandMgr::openCommandSocket that passes structure defined
   in the configuration file. Currently only two parameters are supported: socket-type
   (which must contain value 'unix') and socket-name (which contains unix path for
-  the named socket to be created). This method calls @ref
-  isc::config::CommandSocketFactory::create method, which parses the parameters
-  and instantiates one object from a class derived from @ref isc::config::CommandSocket.
-  Again, currently only UNIX type is supported, but the factory
-  class is expected to be extended to cover additional types.
+  the named socket to be created).
 - @ref isc::config::CommandMgr::closeCommandSocket() - it is used to close the
-  socket. It calls close method on the @ref isc::config::CommandSocket object, if
-  one exists. In particular, for UNIX socket, it also deletes the file after socket
-  was closed.
+  socket.
 
 @section ctrlSocketConnections Accepting connections
 
-Control Channel is connection oriented communication. In that sense it is
-different than all other communications supported so far in Kea. To facilitate
-connections, several mechanisms were implemented. Intially a single UNIX socket
-it opened (see @c isc::config::UnixCommandSocket in
-src/lib/config/command_socket_factory.cc). Its @ref
-isc::config::UnixCommandSocket::receiveHandler callback method is
-installed in @ref isc::dhcp::IfaceMgr to process incoming connections. When the
-select call in @ref isc::dhcp::IfaceMgr::receive4 indicates that there is some data to be
-processed, this callback calls accept, which creates a new socket for handling
-this particular incoming connection. Once the socket descriptor is known, a new
-instance of @ref isc::config::ConnectionSocket is created to represent that
-socket (and the whole ongoing connection). It installs another callback
-(@ref isc::config::ConnectionSocket::receiveHandler that calls
-(@ref isc::config::CommandMgr::commandReader) that will process incoming
-data or will close the socket when necessary. CommandReader reads data from
-incoming socket and attempts to parse it as JSON structures. If successful,
-it calls isc::config::CommandMgr::processCommand(), serializes the structure
-returned and attempts to send it back.
-
-@todo Currently commands and responses up to 64KB are supported. It was deemed
-sufficient for the current needs, but in the future we may need to extend
-it to handle bigger structures.
+The @ref isc::config::CommandMgr is implemented using boost ASIO and uses
+asynchronous calls to accept new connections and receive commands from the
+controlling clients. ASIO uses IO service object to run asynchronous calls.
+Thus, before the server can use the @ref isc::dhcp::CommandMgr it must
+provide it with a common instance of the @ref isc::asiolink::IOService
+object using @ref isc::dhcp::CommandMgr::setIOService. The server's
+main loop must contain calls to @ref isc::asiolink::IOService::run or
+@ref isc::asiolink::IOService::poll or their variants to invoke Command
+Manager's handlers as required for processing control requests.
+
 
 */