JP3051184B2 - Program creation system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a program creation system for managing objects by counting the number of times an instruction in a program uses an object by using a plurality of counters. When counting the number of times of use with separate counters, even if there is a large variation in the count value of each counter, a small memory capacity
It relates to a system that can efficiently count by quantity .

In a system in which a counter for checking the number of times of use of each object in a memory used by each instruction of a program is provided for each object, if the number of objects is large, the number of counters increases, and the memory usage increases. Because of the large volume, reduction is desired. The present invention aims at improving efficiency by eliminating waste of memory caused by a counter having a small count value having the same count capacity as a counter having a large count value.

[0003]

2. Description of the Related Art Recently, an interpreter-type program creation system that can create or modify a program interactively and immediately execute the program has been widely used.

In such a program creation system, each instruction in a program specifies a data area, that is, an object, and performs processing. For example, "Posting A →
"B" indicates that the data of the object A is transferred to the object B.

[0005] The objects referred to by each instruction are collectively arranged on a main storage device and managed by an object management table. FIG. 5 shows a specific example.

In FIG. 5, 1 is a main storage device, 2 is an object group composed of a plurality of objects, 3 is an object management table, 4 is an object table item in the object management table 3, 5 is a pointer to the object and an object length. 6 is a 4-byte counter for counting the number of times an object is referenced by an instruction for program evaluation, and 7 is an instruction.

[0007] An arbitrary one of the object table items 4 of the object management table 3 corresponds to one object in the object group 2 and is commanded by object identification information OID (object table item numbers 0 to 6 in the illustrated example). 7.

The instruction 7 has an OP part for designating processing contents such as transcription and calculation, and an OID part for designating one or a plurality of object identification information OID. When the instruction 7 is executed, the corresponding object table item 4 of the object management table 3 is referred to by the specified contents of the OID part, and the object is accessed using the pointer in the object management information 5. When an object is accessed, the counter 6 of the corresponding object table item is incremented by one. Further, when an instruction is added or deleted in the program, a necessary count value is corrected for the counter. FIG. 5 illustrates a count value of each counter.

The objects used by the instructions in the program depend on the processing contents, and may be used repeatedly. In the example of FIG. 5, the objects 2 and 6 are used twice at the lowest and the object 0 is used 5875 times at the highest. Therefore, the size of each counter, that is, the count capacity, is determined so as to sufficiently exceed the maximum number of times that can be expected for all objects.

[0010]

In the object management table in the conventional program creation system, the count capacity of a counter for counting the number of uses of each object is prepared in a size commensurate with the expected maximum number of uses of the object. Therefore, if the total number of objects increases, such as several thousand, the size of the memory area occupied by the counters becomes considerable, and the counter value becomes large due to large variations in the count values of the counters. There was a problem.

An object of the present invention is to configure a plurality of counters having large variations in count values with a small amount of memory used.

[0012]

According to the present invention, the count capacity of a plurality of counters provided for an object is determined.
By setting a value larger than the expected minimum count value and smaller than the maximum count value so that a counter with a large count value causes an overflow and managing the number of overflows in a table corresponding to the counter,
The overall memory usage is smaller than in conventional systems .

FIG. 1 is a diagram showing the principle of the present invention, in which the number of times each of a plurality of objects is used is provided for each object.
Efficient with multiple counters with relatively small counting capacity
Can be counted.

In FIG. 1, reference numeral 1 denotes a main storage device. 2
Is an object group. Reference numeral 3 denotes an object management table, which is referred to by object identification information OID. The OID can be a table item number (entry item number).

Reference numeral 4 denotes an object table item.
5 is object management information including a pointer to the object and an overflow flag. 6 'is a counter for counting the number of times the object has been used.
The count capacity is smaller (for example, 1 byte) than the count capacity (4 bytes) of the counter 6 in the conventional system of FIG. 7 is an instruction for using the object. 8
Is a counter control mechanism, which controls the operation and overflow of each counter 6 'of the object management table 3.

Reference numeral 9 denotes a counter overflow table, which is provided corresponding to the counter when the counter 6 'overflows. At this time, the overflow flag in the object management information 5 is turned ON. The length of each entry element of the counter overflow table 9 is, for example, 5 bytes and the object management table 3
A link is set between the corresponding object table item 4 and. The link writes the object identification information OID to the counter overflow table 9 or
This can be realized by setting a pointer in the object table item 4. Here, it is assumed that the former method is employed.

When the instruction 7 is executed, the corresponding object table item 4 is read by referring to the object management table 3 based on the contents of the OID part of the instruction, and the object is accessed using the pointer included in the object management information 5. Then, the instruction is processed. At this time, the counter control mechanism 8 is activated at the same time. The counter control mechanism 8 is also activated when an instruction is added, deleted, or changed.

When activated by execution of an instruction, the counter control mechanism 8 increments the counter 6 'corresponding to the accessed object by one. If an overflow occurs at that time, the overflow flag is checked.
, The count value indicating the number of overflows of the counter 6 'in which the overflow has occurred is incremented by one.

On the other hand, when the overflow flag is OFF, the flag is turned ON and the count value “1” is registered in the counter overflow table 9. The above operation is repeated every time the instruction 7 refers to an object.

In the example of FIG. 1, the size of the counter 6 'is 1
Bytes, and the count capacity is two decimal digits “00 to 2”.
55 ", so the count values" 1024 "," 444 "
The upper two digits of "8" and "5875" overflow and are managed by the counter overflow table 9, respectively.

[0021]

[Operation] According to the present invention, the number of occurrences of a plurality of events to be counted by a plurality of counters has a large variation. In particular, the number of events having a large number of occurrences is small, and the number of occurrences of most events is small. It is effective in the case.

The difference between the operation of the conventional system and the operation of the present invention will be described with reference to FIG. FIG. 2A shows an example of n counters and a variation in count value according to the conventional method. Here, the size of each of the n counters is N bytes. Where N
Assuming that the number of counters having a count value exceeding M bytes satisfying>M> 0 is a small number i and the count values of most of the remaining ni counters are within M bytes. , At least the upper NM bytes of the Ni counters are wasted.

On the other hand, in the case of the method of the present invention shown in FIG. 2B, the size of the n counters is M bytes, and the overflow of the i counters whose count value is larger than M bytes is determined by the counter. By managing with the overflow table, for most of the ni counters, a memory area of NM bytes can be saved, and as n increases, n >> i and N >> M The savings effect is greater.

[0024]

FIG. 1 shows an embodiment of the counter control mechanism 8 and the counter overflow table 9 shown in FIG.
This will be described with reference to FIG. The elements in FIG. 1 are referred to as necessary.

FIG. 3 is a control flow of the counter control mechanism. Here, there are three types of processing required for the counter control mechanism: reference to the counter, counting up of the counter, and counting down of the counter. The countdown of the counter occurs when an instruction is deleted. Hereinafter, the steps of the flow will be described according to reference numerals to (14).

[0026] When the counter control mechanism 8 is activated,
First, the count value of the counter 6 'is read from the object table item 4 referred to in the object management table 3. . Further, it is checked whether the overflow flag is ON. . When the overflow flag is ON, the corresponding overflow count value is read from the counter overflow table 9.

[0027] Next, it is checked whether the processing request is a counter reference. . If the processing request is not a counter reference, it is next checked whether the counter is counting up or counting down. . If the processing request is a reference to a counter, the count value read in step (1) is returned to the request source.

[0028] If the processing request is a count-up of the counter, the count value read by is incremented by +1 to update the counter 6 '. . Check to see if overflow has occurred as a result of counting up with. . If an overflow has occurred, it is next checked whether the overflow flag is ON.

(10). If the overflow flag is ON, the overflow count value read out is incremented by +1 to update the counter overflow table 9. (11). If the overflow flag is OFF, the overflow flag is turned ON, an entry is set in the counter overflow table, and the overflow count value "1" is registered. (12). If the processing request is countdown in step (5), the count value of the counter 6 'read in step (1) is counted down by -1 to update the counter 6'.

(13). It is checked whether a borrow (underflow) has occurred in the counter 6 '. (14). If a borrow has occurred in (13), the overflow count value read out is further decremented by -1 and the counter overflow table 9 is updated. If the overflow count value becomes "0" at this time, the corresponding entry in the counter overflow table 9 is deleted and the overflow flag is turned off.
Return to

The operation of the above flow is executed for each processing request. FIG. 4 shows an embodiment configuration of the overflow table. The table item number in the figure is the number of the object table item 4 in which the overflow has occurred in the object management table 3, and the overflow counter value is set in the overflow counter.

[0032]

According to the present invention, in the created program
For each object used by this instruction,
No matter how large or small the variability is, small memory usage
The maximum count value of the counter for each object by the amount
Because it can be guaranteed large enough,
A program creation system with low power consumption can be provided .

[Brief description of the drawings]

FIG. 1 is a diagram showing the principle of the present invention.

FIG. 2 is an explanatory diagram showing the operation of the present invention.

FIG. 3 is a control flowchart of a counter control mechanism according to the embodiment of the present invention.

FIG. 4 is a configuration diagram of a counter overflow table according to the embodiment of the present invention.

FIG. 5 is an explanatory diagram of a conventional counter method.

[Explanation of symbols]

 1: Main storage device 2: Object group 3: Object management table 4: Object table item 5: Object management information 6: Counter 7: Instruction 8: Counter control mechanism 9: Counter overflow table

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Sadahiro Kitano 1015 Uedanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Inside Fujitsu Limited (56) References JP-A-60-8935 (JP, A) JP-A-63- 748 (JP, A) JP-A-62-221731 (JP, A) JP-A-48-101850 (JP, A) JP-A 64-42747 (JP, A) (58) Fields investigated (Int. ⁷ , DB name) G06F 9/30 310-390

Claims (1)

(57) [Claims] 1. A method comprising: a plurality of objects used by an instruction in a program;
A program that counts and manages the number of uses for each object.
In program creation system manages a <br/> plurality of counters fixed size corresponding to each of said plurality of objects, the number of overflow the plurality of counters, said plurality of
A counter overflow table having a smaller number of entries than the number of the counters, and when any one of the plurality of counters first overflows during operation, an entry corresponding to the counter is stored in the counter overflow table. A counter control mechanism for setting an overflow count value and controlling the overflow counter value to be updated by one each time the same counter overflows thereafter.
Programming system characterized in that it comprises.