SAFplus 7 Feature Discussion

SAFplus Messaging

Advanced Socket Layer

The socket abstraction (MsgSocket class) presents a simple read/write API for multiple scatter gather messages, consisting of receive, send, and flush APIs. At the message transport layer, an instance of the socket object directly communicates with the Linux level socket via system calls. However additional socket objects can be created that implement additional functionality, such as traffic shaping, message segmentation and reassembly and reliable messaging. These message sockets can modify the messages sent and received and then call a lower level MsgSocket instance.

Functionality can therefore be selected at socket construction time by instantiation of a stack or tree of MsgSocket-derived classes, and a single implementation of an abstract concept (such as traffic shaping) can be applied to any message transport type.

After socket construction, application code is unaware that it is accessing layered sockets rather than a direct socket implementation, making it easy to change add or remove functionality as application requirements change.

MsgSocketLayering.svg