Accesses

Accesses define the interaction between domains and shared resources. Thus, effectively accesses define the information flow between two domains. CDS Framework Toolkit provides three forms of access to support of information flow applications: read, write and readwrite. A read access defines information transfer from a shared resource to a domain, while a write access specifies information transfer from a domain to a shared resource. A readwrite access represents information flow in both directions.

As shown in the figure below, accesses are represented graphically using arrows. The arrows indicate the direction of information transfer. For write the arrow points from a domain to a resource to show the information flow from domain to resource. For read access the arrow points from resource towards the domain to show the information flow from resource to domain. In this example, the domain ftp is writing to the resource incoming and the domain virus_scan is reading the information from this resource. So as ftp is writing to incoming, virus_scan is reading this information.