CReMeS: a CORBA compliant reflective memory based real-time communication service

Presents CReMeS (CORBA-compliant Reflective Memory-based Service), a CORBA-compliant design and implementation of a new real-time (RT) communication service. The CReMeS architecture is based on MidART's RT-CRM (Real-Time Channel-based Reflective Memory), which supports the separation of QoS specification between data producers and consumers and employs a user-level scheduling scheme for communicating RT tasks. Although RT-CRM provides a predictable and scalable asynchronous communication infrastructure for applications, it is not a standard middleware. To make its service widely available, we developed CReMeS by adapting RT-CRM for CORBA environments. As a result, CReMeS provides efficient, predictable and scalable communication between information producers and consumers. Since CReMeS provides a CORBA interface to applications and demands no changes to the ORB layer and the language mapping layer, it can run on non-RT off-the-shelf ORBs and enables applications on these ORBs to have scalable and end-to-end predictable asynchronous communication facility. In addition, an application designer can select whether to use an out-of-band channel or the ORB GIOP (General Inter-ORB Protocol)/IIOP (Internet Inter-ORB Protocol) for data communication. This permits a tradeoff between performance, predictability and reliability. Our architecture achieves better performance and predictability than a RT implementation of the CORBA Event Service when the out-of-band channel is employed for data communication; it delivers better predictability with comparable performance when the ORB GIOP/IIOP is used.