System for transferring I/O data between an I/O device and an application program's memory in accordance with a request directly over a virtual connection

摘要

A virtual connection created between an application program and a selected I/O device is used as a communications medium for controlling I/O processing of the I/O device by the application program. The virtual connection is implemented as a system area network connecting a process of the application program and the I/O device. The application program registers the application program's memory that the application program shares with the I/O device (i.e., gives access rights to the I/O device) with the system area network. Once the virtual connection is created and initialized, the application program uses the virtual connection to send request messages for I/O services to the I/O device and to receive reply messages from the I/O device. The I/O device uses the virtual connection to obtain source data from the application program's memory for I/O write operations and to transfer data to the application program's memory for I/O read operations.