Browse Prior Art Database

Control Block With Two Blocks for Controlling Access to the Control Block by Channels Reporting a Previous Control Unit Busy Condition And Channels Handling a Data Transfer

IP.com Disclosure Number: IPCOM000065944D
Original Publication Date: 1985-Dec-01
Included in the Prior Art Database: 2005-Feb-19

Publishing Venue

IBM

Related People

Authors:
Wu, BH [+details]

Abstract

In a system in which a control block for an I/O device is shared by a central processor and several channel processors, two locks are provided that permit the channel processors to access the control block synchronously for data transfer operations and for an operation to report a previous condition that a control unit was busy and permit an error to be conventionally signaled if one channel processor attempts to access the control block for a data transfer operation when it has been locked for a data transfer operation by another channel processor.