JP2003036123A - Time management system for computer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a time management system for a computer which allows respective virtual machines on a computer having a plurality of virtual machine functions by itself to have unique times. SOLUTION: The virtual machines A and B read in the current time from an internal clock of the computer or a base OS and add relative time optionally set by the virtual machines to the current time to have their internal clocks.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a computer having a plurality of virtual machine functions, and more particularly to a time management system in each virtual machine. 2. Description of the Related Art In recent computers, due to the improvement of processing performance, a plurality of virtual machines are simulated on one computer by simulating another type of operating system (OS) on one computer. It is possible to operate the machine. [0003] Thus, application software running on different types of OSs can be simultaneously executed on one computer. [0004] In the above-described computer, the time information used by each virtual machine is, as shown in FIG.
The system time in S is used for reading and writing as the current time. For this reason, the current times of the plurality of virtual machines always match. [0005] However, there is a case where only a certain virtual machine wants to change the time and execute processing. For example, when testing application software whose time is very important using a specific virtual machine, it is necessary to change the time. However, the application software cannot be operated based on an arbitrary time without changing the time of the computer itself. SUMMARY OF THE INVENTION An object of the present invention is to provide a computer time management system in which a single computer having a plurality of virtual machine functions can give each virtual machine a unique time. According to the present invention, in order to solve the above-mentioned problems, each virtual machine has a time obtained by adding a relative time unique to the virtual machine to a current time on a computer or a base OS. It has a time management function, and is characterized by the following configuration. In one computer having a plurality of virtual machine functions and having a common system clock for each virtual machine, each virtual machine reads the current time from the system clock, and reads the current time for each virtual machine. It is characterized by having a time management function that adds an arbitrarily set relative time to set the internal time of the machine. FIG. 1 is a functional block diagram for time management showing an embodiment of the present invention. Virtual machine A
And the virtual machine B have a time management function of reading the current time on the computer or the base OS as their internal time, and adding a unique relative time arbitrarily set in advance to the virtual time to the current time. . The internal time of the virtual machine = the base OS time + the relative time peculiar to the virtual machine, that is, the relative time peculiar to each virtual machine (having positive and negative polarities) can be set, and the internal time of the virtual machine can be set. Is managed as a relative time from the time held by the computer or the base OS. For example, in FIG. 1, the current time of the computer or the base OS is “September 27, 2000, 10:
In the case of “40:30”, the virtual machine A reads the current time as the relative time = 0, and adds “10: 40: 3 on September 27, 2000” to the internal time obtained by adding the relative time to the current time.
"0" and machine processing using the same time information as the current time. On the other hand, in virtual machine B, its relative time =
The current time is read as -1 year, and the internal time obtained by adding the relative time to the current time is added to "10:40: September 27, 1999:
30 "is obtained and machine processing is performed. As described above, each virtual machine has a base O
By providing a time management function for adding the relative time set for each machine to the current time such as S, the relative time can be set for the virtual machine to have its own time. At this time, even if the time in the virtual machine is changed,
It does not affect other virtual machines. In addition, if the time in the virtual machine is managed by the absolute time, an error due to time adjustment appears. However, since the time is adjusted by the relative time, no error occurs. When it is desired to match the time between virtual machines, the relative time may be the same, and by setting the relative time to 0, all the machines have the same time as in the conventional time management method. be able to. In FIG. 1, two virtual machines A and B
However, the present invention can be applied to a computer having three or more virtual machine functions to realize an equivalent computer. As described above, according to the present invention, each virtual machine is provided with a time management function that sets a time obtained by adding a relative time unique to the virtual machine to the current time on the computer or the base OS. Therefore, each virtual machine can have a unique time.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a functional block diagram for time management according to an embodiment of the present invention. FIG. 2 is a functional block diagram for conventional time management. [Description of Signs] A, B: Virtual Machine

Claims (1)

Claims: 1. A computer having a plurality of virtual machine functions in a single machine and having a system clock common to each virtual machine, wherein each virtual machine reads a current time from the system clock, and A time management method for a computer, comprising a time management function of adding a relative time arbitrarily set for each virtual machine to a current time and setting the time as an internal time of the virtual machine.