New I/O devices with data rates ranging from 10 to 100 Mbytes per second are becoming available for personal computers and workstations. These include human-interaction devices for video capture and display (and audio record and playback), high-capacity storage devices, and high-speed network communication devices. These devices have enabled I/O-intensive applications for desktop computing that require input, processing, and output of very large amounts of data. This article focuses on an important aspect of operating system support for these applications: efficient transfer of large data objects between the protection domains in which processes and devices reside. Many operating systems are inefficient in transferring large amounts of data between domains. Most of them, even when they try to avoid physical copying, offer a data-transfer model that assumes a need for complete accessibility to all transferred data. This assumption leads to overheads that can other wise be avoided. The authors' design for an interdomain transfer facility (which was inspired by the ''container-shipping'' solution from the cargo-transportation industry) is based on virtual transfers and avoids all unnecessary physical copying.
