System Architecture Analysis Sample Clauses

System Architecture Analysis. When generating support for the distributed aspects of a VDM-RT model, the relevant architecture information must be extracted from the system class definition. The following information must be extracted: Which CPU instances are created. This indicates the individual micro- processors of the system, i.e. each CPU will get its own code imple- mentation. Specifically, each CPU receives its own local representation of the system definition, containing the objects deployed to it. Which BUS instances are created. This indicates the communication channels created in the system. How the objects in the system definition are deployed to each CPU in- stance. This indicates which object has to be instantiated with respect to the implementation of a specific CPU instance. How the CPU instances are connected based on the BUS instances. This indicates the communications architecture between the different pro- cessors. These four parts will in combination support the realization of a VDM-RT model. This architecture analysis is automatically performed by the code generator. The four points above can be illustrated using the simple example from Listing 21: Two implementations will be code generated for the two CPU instances cpu1 and cpu2, respectively. Furthermore, each implementation con- sists of a local version of the system definition, generated as a class, containing information about local and remote objects. The BUS instance will be realized by a specific hardware bus, e.g. UART or CAN bus, and a communication protocol. In this example the objects c and s1 are deployed to the code imple- mentation of cpu1, while s2 is deployed to cpu2. The CPU instances cpu1 and cpu2 are connected by the BUS instance bus. Hence the communication between these two will go through the bus instance. This system architecture information supports the invocation dispatching between local and remote method invocations, as discussed in the following section.