Random number generating apparatus and random number generating method in a multiprocessor system

• US 5,793,657 A
• Filed: 04/10/1996
• Issued: 08/11/1998
• Est. Priority Date: 04/11/1995
• Status: Expired due to Fees

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Nemoto, Ryoji
• Primary Examiner(s): Mai, Tan V.
• Application Number:
  US08/630,176
• Time in Patent Office: 853 Days
• Field of Search: 364/717, 380/46
• US Class Current: 708/402
• CPC Class Codes: G06F 7/586 using an integer algorithm, e.g. using linear congruential method

Abstract

An initial value for each processor of a multiprocessor system is set using a specified calculating expression. The system determines a random number calculating expression using a multiplicative congruence method so that random numbers generated from these initial values may make a sequence of random numbers in series, and generates random numbers using the calculating expression. The system permits the adding of a processor in the middle of generation of random numbers by making equal to one another the number of random numbers generated by the existing processors, setting an initial value in each processor on the basis of the total number of already generated random numbers, and generating random numbers according to a sequence of random numbers prior to adding the processor until reaching a specified total number of random numbers to be generated.

Claims

1. A random number generating apparatus in a multiprocessor system, comprising:

a plurality of processors; and

a processor managing means for setting in advance initial values for said processors;

wherein said processors simultaneously generate random numbers on the basis of the initial values; and

wherein said processor managing means arranges the random numbers generated by the processors to produce a sequence of periodically repeated random numbers.

2. A random number generating apparatus in a multiprocessor system as defined in claim 1, wherein said processor managing means adds an additional processor for generating random numbers during generation of the random numbers by said plurality of processors, resets said initial values for generating the random numbers in the respective plurality of processors and the additional processor, and arranges the random numbers generated by said respective processors to produce on the basis of the reset initial values the sequence of periodically repeated random numbers.

3. A random number generating apparatus in a multiprocessor system, comprising:

a plurality of processors;

a processor managing means for setting in advance initial values for said processors, said initial values being based in part on a number of random numbers to be generated by said processors;

wherein said processors simultaneously generate random numbers on the basis of the initial values; and

wherein said processor managing means arranges said random numbers generated by the respective processors to produce a sequence of periodically repeated random numbers.

4. A random number generating apparatus in a multiprocessor system as defined in claim 3, wherein said processor managing means adds an additional processor for generating random numbers during generation of random numbers by said plurality of processors, resets said initial values for generating the random numbers with the respective Plurality of processors and the additional processor, and arranges the random numbers generated by said respective processors and the additional processor to produce on the basis of the reset initial values the sequence of periodically repeated random numbers.

5. A random number generating apparatus in a multiprocessor system, comprising:

a plurality of processors for generating random numbers;

a storing means;

a processor managing means for setting initial values for said processors and for storing said initial values in said storing means;

wherein the processor managing means sets a number of random numbers to be generated by each processor on the bases of the total number of random numbers to be generated in the whole multiprocessor system and the number of said plurality of processors;

wherein said processors simultaneously generate random numbers on the basis of the initial values stored in said storing means; and

wherein the processor managing means arranges said random numbers generated by the respective processors to produce a sequence of periodically repeated random numbers which are stored in said storing means.

6. A random number generating apparatus in a multiprocessor system as defined in claim 5, wherein said processor managing means adds an additional processor for generating random numbers while said plurality of processors are generating random numbers, resets the initial values for generating the random numbers in the respective processors including the additional processor, and stores said initial values in said storing means;

wherein said processor managing means sets the number of random numbers to be generated by each processor on the bases of the total number of random numbers to be generated in the whole multiprocessor system and the number of processors for generating random numbers, and;

wherein said plurality of processors and said additional processor generate random numbers on the basis of said reset initial values; and

wherein said processor managing means arranges the random numbers generated by said plurality of processors and said additional processor to generate a sequence of periodically repeated random numbers which are stored in said storing means.

7. A random number generating apparatus in a multiprocessor system as defined in claim 5, wherein

an additional random number generating processor is added during generation of the random numbers by said plurality of processors, and said processor managing means controls each of said plurality of processors so as to generate random numbers up to a number obtained by adding an arbitrary number to the number of random numbers generated by one of said plurality of processors which has generated the greatest number of random numbers;

wherein said processor managing means resets an initial value for each of said plurality of processors and said additional processor to generate random numbers on the basis of the number of random numbers already generated by said plurality of processors, and stores said reset initial value for each of said plurality of processors and said additional processor in said storing means;

wherein said processor managing means sets the number of random numbers to be generated by said additional processor and said plurality of processors on the bases of the total number of random numbers to be generated in the whole multiprocessor system, the number of already generated random numbers, and the number of said plurality of processors and said additional processor; and

wherein said processor managing means arranges the random numbers generated by the respective processors on the basis of said reset initial values and the number of already generated random numbers to produce a sequence of periodically repeated random numbers which are stored in said storing means.

8. A random number generating apparatus in a multiprocessor system, comprising:

a plurality of processors for generating random numbers;

a storing means;

a processor managing means for setting initial values for said processors and for storing said initial values in said storing means, said initial values being determined by means of an expression;

space="preserve" listing-type="equation">X.sub.n =X * a.sup.n mod M,

where a, X, and M are integers, 0≦

X<

M, and n is the number of said plurality of processors;

wherein the processor managing means sets a number of random numbers to be generated by each of said plurality of processors on the bases of the total number of random numbers to be generated in the whole multiprocessor system and the number of said plurality of processors the number of random numbers to be generated being equal to the total number of random numbers to be generated divided by the number of said plurality of processors, minus one;

wherein the processor managing means arranges the random numbers generated by the respective processors on the basis of said initial values to produce a sequence of random numbers which are stored in said storing means, said sequence of random numbers being produced by said processing managing means by means of an expression;

space="preserve" listing-type="equation">X.sub.n+n =a.sup.r * X.sub.n+r(t-1),

where X is an integer, a is an initial value, r is the number of processors, n is a processor number, t is a natural number, and

1≦

t≦

the number of generated random numbers.

9. A random number generating apparatus in a multiprocessor system as defined in claim 8, wherein

an additional random number generator processor is added during generation of the random numbers by said plurality of processors, and said processor managing means controls each of said plurality of processors so as to generate random numbers up to a number obtained by adding an arbitrary number to the number of random numbers generated by one of said plurality of processors which has generated the greatest number of random numbers;

wherein said processor managing means resets an initial value for each of said plurality of processors and said additional processor to generate random numbers on the basis of the number of random numbers already generated by said plurality of processors, and stores said reset initial value for each of said plurality of processors and said additional processor in said storing means, said random numbers being generated by means of an expression;

space="preserve" listing-type="equation">X.sub.q+n =X.sub.q * a.sup.n mod M,

where a, X, and M are integers, 0≦

X<

M, n is a processor number, and q is the total number of random numbers generated by the plurality of processors;

wherein said processor managing means sets the number of random numbers to be generated by each processor on the bases of the total number of random numbers to be generated in the whole multiprocessor system, the number of already generated random numbers, and the number of processors for generating random numbers;

wherein the number of random numbers to be generated equals {(the total number of random numbers to be generated minus the number of already generated random numbers) divided by the number of processors} minus one; and

wherein said processor managing means arranges random numbers generated by the respective processors on the basis of said reset initial values and the number of already generated random numbers to produce a sequence of random numbers which are stored in said storing means, said sequence of random numbers being obtained by means of an expression;

space="preserve" listing-type="equation">X.sub.n+q+rt =a.sup.r * X.sub.n+q+r(t-1),

where X is an integer, a is an initial value, r is the number of processors, n is a processor number, q is the total number of random numbers generated by all the existing processors, t is a natural number, and 1≦

t≦

the number of generated random numbers.

10. A method for generating random numbers in a system that includes a plurality of processors, comprising the steps of:

setting in advance initial values for said processors;

simultaneously generating random numbers with said processors on the basis of the initial values; and

arranging the random numbers generated by the processors to produce a sequence of periodically repeated random numbers.

11. A method as defined in claim 10, further comprising the steps of:

adding an additional random number generating processor during generation of the random numbers by said processors;

resetting said initial values for generating random numbers with the plurality of processors and the additional processor; and

arranging the random numbers generated by said respective processors to produce, on the basis of the reset initial values, a sequence of periodically repeated random numbers.

12. A method for generating random numbers in a system that includes a plurality of processors, comprising the steps of:

setting in advance initial values for said processors, said initial values being based in part on a number of random numbers to be generated by said processors;

simultaneously generating random numbers with said processors on the basis of the initial values; and

arranging the random numbers generated by the processors to produce a sequence of periodically repeated random numbers.

13. A method as defined in claim 12, further comprising the steps of:

adding an additional random number generating processor during generation of the random numbers by said processors;

resetting said initial values for generating random numbers with the plurality of processors and the additional processor; and

arranging the random numbers generated by said respective processors to produce, on the basis of the reset initial values, a sequence of periodically repeated random numbers.

14. A method for generating random numbers in a system that includes a plurality of processors, comprising the steps of:

setting initial values for said processors;

storing said initial values in a storing unit;

simultaneously generating random numbers with said processors on the basis of the initial values; and

arranging the random numbers generated by the processors to produce a sequence of periodically repeated random numbers which are stored in said storing unit.

15. A method as defined in claim 14, further comprising the steps of:

adding an additional random number generating processor during generation of random numbers by said processors;

resetting said initial values for generating random numbers with the plurality of processors and the additional processor;

storing the reset initial values in said storing unit;

setting the number of random numbers to be generated by each processor on the bases of the total number of random numbers to be generated in the whole multiprocessor system and the number of said processors; and

arranging the random numbers generated by said respective processors to produce, on the basis of the reset initial values, a sequence of periodically repeated random numbers.

16. A method as defined in claim 14, further comprising the steps of:

adding an additional random number generating processor during generation of random numbers by said plurality of processors;

controlling each of said plurality of processors so as to generate random numbers up to a number obtained by adding an arbitrary number to the number of random numbers generated by a one of said plurality of processors which has generated the greatest number of random numbers;

resetting an initial value for each of said plurality of processors and said additional processor to generate random numbers on the basis of the number of random numbers already generated by said plurality of processors;

storing the reset initial value for each of said plurality of processors and said additional processor in said storing unit;

setting the number of random numbers to be generated by said additional processor and said plurality of processors on the bases of the total number of random numbers to be generated in the whole multiprocessor system, the number of already generated random numbers, and the total number of said plurality of processors and said additional processor; and

arranging the random numbers generated by the respective processors on the basis of said reset initial values and the number of already generated random numbers to produce a sequence of periodically repeated random numbers which are stored in said storing unit.

17. A method for generating random numbers in a system that includes a plurality of processors, comprising the steps of:

setting initial values for said processors and storing said initial values in a storing unit, said initial values being determined by means of an expression;

space="preserve" listing-type="equation">X.sub.n =X * a.sup.n mod M,

where a, X, and M are integers, 0≦

X<

M, and n is the number of said plurality of processors;

setting a number of random numbers to be generated by each of said plurality of processors on the bases of the total number of random numbers to be generated in the whole multiprocessor system and the number of said plurality of processors, the number of random numbers to be generated being equal to the total number of random numbers to be generated divided by the number of said plurality of processors, minus one; and

arranging the random numbers generated by the respective processors on the basis of said initial values to produce a sequence of random numbers which are stored in said storing units, said sequence of random numbers being produced by means of an expression;

space="preserve" listing-type="equation">X.sub.n+rt =a * X.sub.n+r(t-1),

where X is an integer, a is an initial value, r is the number of processors, n is a processor number, t is a natural number, and 1≦

t≦

the number of generated random numbers.

18. A method as defined in claim 17, further comprising the steps of:

adding an additional random number generator processor during generation of random numbers with said plurality of processors;

controlling each of said plurality of processors so as to generate random numbers up to a number obtained by adding an arbitrary number to the number of random numbers generated by a one of said plurality of processors which has generated the greatest number of random numbers;

resetting an initial value for each of said plurality of processors and said additional processor to generate random numbers on the basis of the number of random numbers already generated by said plurality of processors, said random numbers being generated by means of an expression;

space="preserve" listing-type="equation">X.sub.q+n =X.sub.q * a.sup.n mod M,

where a, X, and M are integers, 0≦

X<

M, n is a processor number, and q is the total number of random numbers generated by the plurality of processors;

storing said reset initial value for each of said plurality of processors and said additional processor in said storing unit;

setting the number of random numbers to be generated by each processor on the bases of the total number of random numbers to be generated in the whole multiprocessor system, the number of already generated random numbers, and the number of processors for generating random numbers, the number of random numbers to be generated being equal to;

{(the total number of random numbers to be generated minus the number of already generated random numbers) divided by the number of processors} minus one; and

arranging random numbers generated by the respective processors on the basis of said reset initial values and the number of already generated random numbers to produce a sequence of random numbers which are stored in said storing unit, said sequence of random numbers being obtained, by means of an expression;

space="preserve" listing-type="equation">X.sub.n+q+rt =a.sup.r * X.sub.n+q+r(t-1),

where X is an integer, a is an initial value, r is the number of processors, n is a processor number, q is the total number of random numbers generated by all the existing processors, t is a natural number, and 1≦

t≦

the number of generated random numbers.