Processes, Invocation, and Objects Like the V-System, Vanguard is defined by a suite of request and response messages. This style of request messagedenoting a distinct local object managed by the server processwas so common in V that in Vanguard we chose to make it a fundamental part of the IPC model. The transport server then delivers the message to the appropriate remote kernel, using a transport protocol suited to the interconnect. A rebooting kernel does not attempt to resurrect servers with their old ids. Object ids identify all operating system services, including those services that are exported by the kernel itselffor example devices and address spaces.
Processes are also objects, managed by a kernel process server.
As an object, a process can be operated on just like any other object, by sending a message to its manager, the process server. To reduce the complexity of the Vanguard interface, objects are classified in an abstract type hierarchy. However, if clients are programmed in an object-oriented language, then it is natural to use programming language objects as message stubs encapsulating Vanguard objects. Similarly, programming language objects can be used in server implementations. Object Groups One of the more noteworthy features of the V-System was its notion of a process group.