Fault-tolerant systems: A computer system with both hardware and software that are capal operation even in the event hardware components fail. File system: The logical organization of files on a storage device, typically a disk drive. The file system may Interprocess communication: The transfer of information between two cooperating programs. Commun cation may take the form of a signal (the arrival of an event)or the transfer of data. Parallel processing: A parallel computer is one that contains more than one CPU Parallel processing is when a program is divided into multiple threads of control, each of which is capable of running simultaneousl On a parallel computer, multiple threads could be running at the same time, thus resulting in better Process: A single executable program. A the context in which an operating system places a running program. It contains the program itse as allocated memory, open files, network connections, etc. Real-time computing: Support for env in which response time to an event must occur within a predetermined amount of time. Real-time systems may be categorized into hard and soft real-time Related Topics 90.3 Programming Methodology. 95.2 Classification erences AT&T, System V Interface Definition, Spring 1985, Issue 1, aT&T Customer Information Center, Indianapolis, Indiana J. Boykin, D. Kirschen, A Langerman, and S. LoVerso, Programming Under Mach, Reading, Mass. Addison J. Boykin and A. Langerman, "Mach/4.3BSD: Parallelization without reimplementation, " Computing Systems Journal, vol. 3, no. 1, 1990. J. Boykin and S. LoVerso, Recent developments in operating systems, "Computer, vol 23, no 5, 1990 HM. Dietel, Operating Systems, 2nd ed, Reading, Mass. Addison-Wesley, 1990 IEEE, Carrier Sense Multiple Access with Collision Detection(CSMA/CD)Access Method and Physical Layer Specifications, American National Standard ANSI/IEEE Std 802.3, 1985 EE, Information Technology--Portable Operating System Interface(POSIX) Part 1: System Application Program Interface(API)/C Language], New York: IEEE, 1990 A. Silberschatz, J L. Peterson, and P.B. Galvin, Operating Systems Concepts, 3rd ed, Reading, Mass. Addison Wesley, 1991. A.S. Tanenbaum, Modern Operating Systems, Englewood Cliffs, N J: Prentice-Hall, 1992 X/Open Portability Guide, X/Open Company Ltd, Englewood Cliffs, N J Prentice-Hall, 1989. Further information Many textbooks describe operating system concepts. The three cited in the reference section [Dietel, 1990; Silberschatz et al., 1991; and Tanenbaum, 1992] are excellent. The IEEE Computer Society has a number of tutorials on operating system related topics such as fault tolerance, real-time, local area networks and distributed processing. Readers should contact the Computer Society Press office at 10662 Los Vaqueros Circle, Los Alamitos, Calif. 90720 Phone: 714-821-8380 For those interested in learning more about the implementation of specific operating systems, M.J. Bach, The Design of the UNIX Operating System, Prentice-Hall, 1986, describes the implementation of AT&T System V The 4.3BSD operating system is described in Leffler et al., The Design and Implementation of the 4.3BSD UNIX Operating System, Addison-Wesley, 1990 e 2000 by CRC Press LLC© 2000 by CRC Press LLC Fault-tolerant systems: A computer system with both hardware and software that are capable of continuous operation even in the event hardware components fail. File system: The logical organization of files on a storage device, typically a disk drive. The file system may support a hierarchical structure with directories and subdirectories (sometimes called folders). Interprocess communication: The transfer of information between two cooperating programs. Communi￾cation may take the form of a signal (the arrival of an event) or the transfer of data. Parallel processing: A parallel computer is one that contains more than one CPU. Parallel processing is when a program is divided into multiple threads of control, each of which is capable of running simultaneously. On a parallel computer, multiple threads could be running at the same time, thus resulting in better performance than on a uniprocessor system. Process: A single executable program. A process is the context in which an operating system places a running program. It contains the program itself as well as allocated memory, open files, network connections, etc. Real-time computing: Support for environments in which response time to an event must occur within a predetermined amount of time. Real-time systems may be categorized into hard and soft real-time. Related Topics 90.3 Programming Methodology • 95.2 Classifications References AT&T, System V Interface Definition, Spring 1985, Issue 1, AT&T Customer Information Center, Indianapolis, Indiana. J. Boykin, D. Kirschen, A. Langerman, and S. LoVerso, Programming Under Mach, Reading, Mass.: Addison￾Wesley, 1993. J. Boykin and A. Langerman, “Mach/4.3BSD: Parallelization without reimplementation,” Computing Systems Journal, vol. 3, no. 1, 1990. J. Boykin and S. LoVerso, “Recent developments in operating systems,” Computer, vol. 23, no. 5, 1990. H.M. Dietel, Operating Systems, 2nd ed., Reading, Mass.: Addison-Wesley, 1990. IEEE, Carrier Sense Multiple Access with Collision Detection (CSMA/CD) Access Method and Physical Layer Specifications, American National Standard ANSI/IEEE Std. 802.3, 1985. IEEE, Information Technology—Portable Operating System Interface (POSIX) Part 1: System Application Program Interface (API) [C Language], New York: IEEE, 1990. A. Silberschatz, J.L. Peterson, and P.B. Galvin, Operating Systems Concepts, 3rd ed., Reading, Mass.: Addison￾Wesley, 1991. A.S. Tanenbaum, Modern Operating Systems, Englewood Cliffs, N.J.: Prentice-Hall, 1992. X/Open Portability Guide, X/Open Company Ltd., Englewood Cliffs, N.J.: Prentice-Hall, 1989. Further Information Many textbooks describe operating system concepts. The three cited in the reference section [Dietel, 1990; Silberschatz et al., 1991; and Tanenbaum, 1992] are excellent. The IEEE Computer Society has a number of tutorials on operating system related topics such as fault tolerance, real-time, local area networks and distributed processing. Readers should contact the Computer Society Press office at 10662 Los Vaqueros Circle, Los Alamitos, Calif. 90720. Phone: 714-821-8380. For those interested in learning more about the implementation of specific operating systems, M.J. Bach, The Design of the UNIX Operating System, Prentice-Hall, 1986, describes the implementation of AT&T System V. The 4.3BSD operating system is described in Leffler et al., The Design and Implementation of the 4.3BSD UNIX Operating System, Addison-Wesley, 1990