Shell

The shell describes the interface of a component or a resource. It contains ports and properties. The shell is the only visible part outside the component/resource.

A Shell is created by extending the mauve::runtime::Shell class.

#include "mauve/runtime.hpp"

struct MyShell: public mauve::runtime::Shell {};

A Shell is configurable, you can then override the configure and cleanup hooks.

Shell Property

Properties can be defined in the Shell as class attributes. The Property class is templated by the underlying type of the property. The mk_property method allows to construct the property and returns a reference on the property object. This method has two arguments: the name of the property (usefull to change the property from configuration files) and a default value.

For instance, the code

struct MyShell: public mauve::runtime::Shell {
  mauve::runtime::Property<int> & age = mk_property<int>("age", 0);
};

defines a property attribute age of type int, with name age and a default value of 0.

Shell properties will be accessible from the shell, the core, and
the finite state-machine of the component, and from the architecture.

Shell Port

Ports are used by components in order to communicate to resources.
There is 4 types of ports: ReadPort, WritePort, CallPort, and EventPort. To be functionnal, a Port needs to be bound to a Service of the same type (see Interface).

For instance, the code

struct MyShell: public mauve::runtime::Shell {
  mauve::runtime::ReadPort<int> & read_age = mk_read_port<int>("read_age", 0);
  mauve::runtime::WritePort<int> & write_age = mk_write_port<int>("write_age");
  mauve::runtime::CallPort<int, std::string> & call_age = mk_call_port<int, std::string>("call_age");
  mauve::runtime::EventPort<> & event_age = mk_event_port<>("event_port");
};

defines:

• a read port read_age of type int, with name read_age and a default value of 0
• a write port write_port of type int with name write_age
• a call port call_port of return type int, parameter type std::string, with name call_age
• an event port event_port with name event_port