United States Patent  in] Patent Number: 5,414,851
Brice, Jr. et al.  Date of Patent: May 9,1995
 METHOD AND MEANS FOR SHARING I/O RESOURCES BY A PLURALITY OF OPERATING SYSTEMS
 Inventors: Frank W. Brice, Jr., Hurley; Joseph C. Elliott, Hopewell Junction; Kenneth J. Fredericks; Robert E. Galbraith, both of Poughkeepsie; Marten J. Halma, Poughquag; Roger E. Hough, Highland; Suzanne M. John, Poughkeepsie; Paul A. Malinowski, Poughkeepsie; Allan S. Meritt, Poughkeepsie; Kenneth J. Oakes, Wappingers Falls; John C. Rathjen, Jr., Rhinebeck, all of N.Y.; Martin W. Sachs, Westport, Conn.; Dand E. Stucki; Leslie W. Wyman, both of Poughkeepsie, N.Y.
 Assignee: International Business Machines Corporation, Annonk, N.Y.
 Appl. No.: 898,867
 Filed: Jun. 15,1992
 Int. CI.6 G06T 3/00
 U.S. CI 395/650; 395/275;
364/DIG. 1; 364/280; 364/281.6; 364/281.3  Field of Search 395/650, 700, 275
 References Cited
U.S. PATENT DOCUMENTS
4,564,903 1/1986 Guyette et al 364/200
4,843,541 6/1989 Bean et al 364/200
4,885,681 12/1989 Umeno et al 395/375
4,967,342 10/1990 Lent et al 364/200
5,170,472 12/1992 Cwiakala et al 395/275
5,251,317 10/1993 Iizuka et al 395/650
5,297,262 3/1994 Cox et al 395/325
FOREIGN PATENT DOCUMENTS 0301275 1/1989 European Pat. Off. G06F 9/46
Primary Examiner—Kevin A. Kriess
Attorney, Agent, or Firm—Bernard M. Goldman
Provides a method for increasing the connectivity of I/O resources to a multiplicity of operating systems (OSs) running in different resource partitions of a computer electronic complex (CEC) to obtain sharing of the I/O resources among the OSs of the CEC, including channels, subchannels (devices), and control units (CUs). The invention provides image identifiers (IIDs) for assigning resources to the different OSs. Each shared I/O resource has a sharing set of control blocks (CBs) in which a respective CB is assigned to (and located by) a respective IID of one of the OSs. Each of the CBs in a sharing set provides a different image of the same I/O resource. The different CB images are independently set to different states by I/O operations for the different OSs, so that the OSs can independently share the same I/O resource.
4,084,224 4/1978 Appell et al. 4,253,145 2/1981 Goldberg ....
30 Claims, 16 Drawing Sheets