class type processor_hooks = object .. end
Processor hooks can be used to modify the behavior of a processor.
    See 
Services And Processors for some documentation about the hooks.
method post_add_hook : socket_service -> controller -> unit
A user-supplied function that is called after the service has been
 added to the controller
method post_rm_hook : socket_service -> controller -> unit
A user-supplied function that is called after the service has been
 removed from the controller
method pre_start_hook : socket_service ->
       controller -> container_id -> unit
A user-supplied function that is called before the container is
 created and started. It is called from the process/thread of the
 controller.
method post_start_hook : container -> unit
A user-supplied function that is called after the container is
 created and started, but before the first service request arrives.
 It is called from the process/thread of the
 container.
method pre_finish_hook : container -> unit
A user-supplied function that is called just before the container is
 terminated. It is called from the process/thread of the
 container.
method post_finish_hook : socket_service ->
       controller -> container_id -> unit
A user-supplied function that is called after the container is
 terminated. It is called from the process/thread of the
 controller.
method workload_hook : container -> bool -> int -> unit
A user-supplied function that is called when the workload
	 changes, i.e. a new connection has been accepted, or an
	 existing connection could be completely processed.
	 The bool argument is true if the reason is a new
	 connection. The int argument is the number of connections.
	 This function is called from the process/thread of the container.
method receive_message : container -> string -> string array -> unit
This function is called when a broadcast message is received.
 The first string is the name of the message, and the array are
 the arguments.
method receive_admin_message : container -> string -> string array -> unit
This function is called when a broadcast admin message is received.
 The first string is the name of the message, and the array are
 the arguments.
method system_shutdown : unit -> unit
A user-supplied function that is called when a system shutdown
 notification arrives. This notification is just for information
 that every container of the system will soon be shut down. The
 system is still completely up at the time this notification 
 arrives, so if the services of other components are required to
 go down this is the right point in time to do that (e.g. send
 important data to a storage component).
method shutdown : unit -> unit
A user-supplied function that is called when a shutdown notification
 arrives. That means that the container should terminate ASAP.
 There is, however, no time limitation. The termination is started
 by calling the when_done function passed to the process method.
method global_exception_handler : exn -> bool
This method is called when an uncaught exception would otherwise
 terminate the container. It can return true to indicate that
 the container continues running.
method container_event_system : unit -> Unixqueue.event_system
method container_run : Unixqueue.event_system -> unit
container_run esys: By default, it just runs esys#run().
	This method is called to run the event system of the containers.
	Users can override it.