System for controlling movement of data in virtual environment using queued direct input/output device and utilizing finite state machine in main memory with two disjoint sets of states representing host and adapter states

Abstract

A method and an apparatus for controlling movement of data between any host and any network including a set of devices in a computing system environment having a main memory with a queuing mechanism having a plurality of queues capable of being shared between a plurality of independent processes running on at least one host and at least one I/O adapter. A finite-state machine (FSM) is provided in the main memory and the FSM is divided into two disjoint sets of states, one of which represents state-values processed by the host and set by the adapter, and said other set represents state-values processed by the adapter and set by said host. Using each of these set of states free-running, non-deadlocking processes are provided within the host and the adapter so that the processes sequence circularly and continuously through a vector related to the FSMs. In addition, a circular data queue is provided in the vector as to further provide a set of storage blocks within said main memory for an input or an output buffer. Using these processes and the queues, data can be moved quickly without any need to initiate any distinct input/output requests or any interruptions by the host processor for completion of each data movement.