JPS6327733B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a program update processing method, particularly during online processing, which makes it possible to check that there will be no conflict in control even if the program is updated without stopping the system or subsystem. The present invention relates to a program update processing method.

With the development of computer technology, the usage patterns of computer systems have diversified, and in particular, the use of so-called 24-hour operation, in which the system operates continuously for long periods without stopping, is becoming more common. In computer systems that operate 24 hours a day, when it becomes necessary to make changes to the programs within the computer system, conventionally the system has to be temporarily stopped to prevent control conflicts. The method used was to update the necessary programs and then restart the system. Therefore, events that occur while the system is stopped at the time of program update have no choice but to be ignored, no matter how urgent they may be. however,
There are many cases in which it is necessary to change a program, such as when partially remodeling a program to improve functionality, or when a program error is discovered and corrected. In this case, in rare cases it was possible to update a program without stopping the system, but if the program to be updated was running, the program's contents could be forcibly changed. The consistency of the processing was disrupted, causing the program to run out of control and the processing results to be unexpected.

SUMMARY OF THE INVENTION In order to solve the above-mentioned drawbacks, it is an object of the present invention to make it possible to check whether or not a program update is possible so that no conflict occurs in control even if the program is updated while the system is in operation. The program update processing method is a program update processing method that dynamically updates programs on memory, and consists of a program management table in which address information for each program managed by the system is registered, and a logical storage space of a predetermined size. The control number counter is set to have a predetermined initial value for each area divided into multiple areas, and the computer execution control directly updates the program status word that holds the address of the instruction to be executed. means for decrementing the control number counter corresponding to the former area by 1 and adding 1 to the control number counter corresponding to the latter area when transitioning from one area to another area by a command other than an instruction to do so and other than an interrupt; , when the execution control of the computer shifts from one area to another area due to an interrupt, means for adding 1 to the control number counter corresponding to the latter area; When moving from one area to another by an instruction that directly updates the program status word holding the area, it is necessary to have a means for decrementing the control number counter corresponding to the former area by 1, and to update the program while the system is running. In this case, the address in the logical storage space occupied by the program to be updated is determined from the program management table, and all or a specific part of the control number counter corresponding to the area including that address is set to the initial setting value. The present invention is characterized in that it includes a processing means for determining whether or not the update is possible on the condition that the update is possible. This will be explained below with reference to the drawings.

FIG. 1 is a schematic diagram illustrating the configuration of an embodiment for updating a control number counter in the present invention, and FIG. 2 is an explanatory diagram illustrating the correspondence between a program on a logical storage space and a control number counter. A shows a state in which control is transferred to program x, FIG. 2B shows a state in which control is not transferred to program x, and FIG. 3 shows an example configuration of a program management table.
FIG. 4 shows an explanatory diagram illustrating one embodiment of program update processing.

In the figure, 1 is a program state word PSW that holds the execution state of the program, 2 is an instruction counter that indicates the logical address of the instruction to be executed within the program state word, and 2-1 is divided by a part of the logical address. The part that indicates a fixed area of logical storage space,
3 is a control number counter, 4 is a signal line for subtraction conditions, 5
is a subtraction check circuit, 6 is an index to the control number counter before control transfer, 7 is an index to the control number counter after control transfer, 8 is an addition check circuit, 9 is a signal line for addition conditions, 10 is a subtraction circuit,
11 is an adder circuit, 12 is a logical storage space, and the shaded area is a program area occupying that space; 12
-1 represents an area of the divided logical storage space, 13 represents a program management table, 14 represents a program for program update processing, and 15 represents an external storage device.

First, the logical storage space is divided into fixed areas of a certain size, such as pages, and a control number counter 3 is provided for each area. If the size of the area is the same as the page, the control number counter 3 may be provided in the page table PGT used for mapping pages of logical addresses and real addresses. The control number counter 3 has an initial value of "0", for example.
However, it is changed in the following cases.

(b) In an instruction (for example, a branch instruction) other than an instruction that directly updates the program state word 1 (for example, a load PSW instruction), the instruction counter 2 calculates that area from the value indicating another area of the partitioned logical storage space. When the value changes to the value shown, the control number counter 3 corresponding to the latter area is incremented by "1".

(b) When the instruction counter 2 changes from the value indicating that area of the partitioned logical storage space to the value indicating another area due to something other than an interrupt (for example, a branch instruction), the control number counter corresponding to the former area is changed to " 1” decrease.

In the above, for example, in a predetermined case such as a load PSW command or an interrupt, the control number counter 3
The reason for adding and subtracting restrictions is that when control is temporarily transferred from the currently executing program to another program due to an input/output interrupt, for example, the control number counter in the area of the original program is This is to prevent the value from becoming 0. Furthermore, the reason why it was decided to perform counting control using the control number counter 3 instead of using a control flag that is displayed with one bit for each area is to take into consideration the multiple running of a so-called reentrant program.

In FIG. 1, for example, among the logical addresses held by the instruction counter 2, if the value of the upper part 2-1 indicating the fixed area of the partitioned logical storage space changes, the execution control of the computer will change from one area to another. This means that the area has moved on. In this case, the subtraction check circuit 5 checks whether the change in the upper part 2-1 of the logical address is due to an interrupt, or uses a mechanism (not shown in the drawings, for example) to suppress the update of the control number counter 3 as necessary. A mechanism is provided to update the control number counter 3 according to a command, receives signals from these mechanisms via a signal line 4, checks whether or not to perform subtraction, and when subtraction is required, sends a notification to the subtraction circuit 10 to that effect. sends out a signal. Subtraction circuit 1
0 subtracts "1" from the corresponding control number counter 3 based on the index 6 to the control number counter 3 whose content is the value of the upper part 2-1 of the logical address before the change. On the other hand, regarding the addition of the control number counter 3 to a new area, as in the case of subtraction, the addition check circuit 8 first checks whether a change in the upper part 2-1 of the logical address is detected by a program state word update command (for example, a load PSW). The addition condition signal via the signal line 9 is checked, and when addition is to be performed, a signal to that effect is sent to the addition circuit 11. The addition circuit 11 adds "1" to the corresponding control number counter 3 based on the index 7 to the control number counter 3 whose content is the value of the upper part 2-1 of the logical address after the change.

By performing the above processing, when control is transferred to program x, as shown in FIG. When the control is not transferred to the program x, the control number counter 3 corresponding to the area occupied by the program x becomes "0" as shown in FIG. 2B.

FIG. 3 is an example of the program management table 13 in which information about programs managed by the system is registered. The starting logical address, the size of the program, etc. are stored. This is used for program update processing, which will be described later.

If it becomes necessary to change the program without stopping the system while the system is running, for example,
A program 14 for the program update process shown in the figure is prepared. The update processing program 14 first prepares a program ID, correction data, a relative address or logical address from the beginning of the program of the correction part, and based on that information, refers to an entry with a matching program ID in the program management table 13. go. When a corresponding entry is found, check for errors, such as whether the address of the specified modification location is outside the range of the program, based on the starting logical address and program size. , performs processing such as determining the logical address to be modified from the relative address. Note that if necessary, for example, in a system having multiple logical storage spaces, where the logical storage space of the update processing program 14 and the logical storage space 12 of the program to be updated are different, for example, the segment/segment used for address mapping may be changed. It also performs processing such as switching or copying tables to match the logical storage space of the update processing program 14 to the logical storage space 12 of the program to be updated. Next, the control number counter 3 corresponding to the area of the logical storage space 12 occupied by the program to be updated is referred to to check whether the update is possible. In this case, the condition for updating may be that the control number counters 3 of all areas occupied by the program are all "0", or by specifying it when starting the update processing program 14, The condition for updating may be that the control number counter 3 has become "0". For example, for a program that is waiting for the occurrence of an event to be processed, even if the corresponding control number counter 3 is not necessarily "0", there may be no control conflict when updating the program. Because you will get it. If the update conditions are not satisfied and the update is not possible, the update processing program 14 may be abnormally terminated, or the update processing program 14 may be made to wait for a certain period of time and then the update is checked again. When the update conditions are satisfied and the update becomes possible, the area of the program to be updated is accessed and the target program is updated. During this time, it will be more reliable if processing is performed with interrupts disabled or lock/unlock control is performed. After updating the program on the main memory as described above, the program on the external storage device 15 such as a magnetic disk device is also updated using a known method. In this way, even when the program is reloaded from the external storage device 15, the updated state will be maintained.

As explained above, according to the present invention, by checking whether the program can be updated using the control number counter, it is possible to update the program without interrupting the system even during online processing. become.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram illustrating the configuration of an embodiment of updating the control number counter in the present invention, FIG. 2 is an explanatory diagram illustrating the correspondence between the program on the logical storage space and the control number counter, and FIG. 3 is the program FIG. 4 shows an explanatory diagram illustrating an embodiment of the program update process. In the figure, 1 is a program state word PSW, 2 is an instruction counter, 3 is a control number counter, 10 is a subtraction circuit, 11 is an addition circuit, 12 is a logical storage space, and 13
14 represents a program management table, and 14 represents a program for program update processing.

Claims (1)

[Claims] 1. In a program update processing method that dynamically updates programs on a memory, a program management table in which address information of each program managed by the system is registered, and a logical storage space allocated to a predetermined area. A control number counter that has a predetermined initial setting value for each area divided into multiple areas of different sizes, and a computer execution control that directly reads the program status word that holds the address of the instruction to be executed. Means for subtracting 1 from the control number counter corresponding to the former area and adding 1 to the control number counter corresponding to the latter area when transitioning from one area to another by a command other than an update instruction and other than an interrupt. and means for adding 1 to the control number counter corresponding to the latter area when the execution control of the computer shifts from one area to another area due to an interrupt; means for decrementing the control number counter corresponding to the former area by 1 when moving from one area to another by an instruction that directly updates a program status word holding an address; If necessary, use the program management table above to
Find the address in the logical storage space occupied by the program to be updated, and determine whether or not it can be updated on the condition that all or a specific part of the control number counter corresponding to the area containing that address is at the initial setting value. A program update processing method comprising: a processing means for determining.