Appeal 2007-2127
Reexamination Control No. 90/006,621
g. Concurrent execution
"Concurrent" and "concurrent execution" are defined in the Microsoft
Press Computer Dictionary:
concurrent A term applied to a computer operation in which two or
more processes (programs) have access to the microprocessor's
time and are therefore carried out more or less at the same time.
Because a microprocessor can work with much smaller units of
time than people can perceive, concurrent processes appear to be
occurring simultaneously but in reality are not.
concurrent execution Also called parallel execution. The apparently
simultaneous execution of two or more routines or programs.
Concurrent execution can be accomplished on a single processor
by using time-sharing techniques such as dividing programs into
different tasks or threads of execution, or by using multiple
processors.
Although "concurrent" is defined as "running parallel" or "operating
or occurring at the same time," Webster's New Collegiate Dictionary
(G. & C. Merriam Co. 1977), "at the same time" does not require at "exactly
the same time" in the computer art. See LaFore, Peter Norton's Inside OS/2,
page 8 (describing a time-sharing system with several users):
Notice that when we speak of two programs running at the same time
in a time-sharing system we don't really mean at exactly the same
time, since the CPU allots a time slice to only one user at a given
time. To the users it appears that many programs are running at the
same time (concurrently), but in reality the CPU runs user A's
program for a few milliseconds, then user B's program, and so on for
several or a dozen users. It then returns to give user A another time
slice. It is only the rapidity of this round-robin switching of CPU time
that provides the illusion of concurrency to the users.
31
Page: Previous 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 Next
Last modified: September 9, 2013