JPH0612524B2 - Object execution control method - Google Patents

Description

DETAILED DESCRIPTION [Outline] For example, in a small-scale data processing system using an 8-bit processor or the like, a memory allocation unit of a program and data is managed as an object including management information of itself, and at the time of execution, By dynamically arranging predetermined objects in memory when needed, and by providing a means for sequentially passing execution control to each object, development of an application system is facilitated and memory efficiency is improved. It is possible to use.

[Industrial application field]

The present invention relates to a program execution control method in a so-called personal computer or the like, and more particularly to an object execution control method that enables efficient system development by incorporating an object-oriented concept.

For example, a personal computer system using an 8-bit processor has an address space limitation of 64 KB, but it is desirable to be able to easily develop a large program without using a complicated memory management mechanism. ing.

[Conventional technology]

For example, in a personal computer or the like, in addition to hardware, as an environment for running applications, BA
The SIC interpreter is often provided integrated with a basic control program. However, a program written in the BASIC language has a problem that its execution performance is extremely deteriorated as compared with a program developed by an assembler or the like.

Therefore, it is considered to develop packages such as game software and educational software in assembler, but a basic operating system that provides a general-purpose operating environment is required to run the developed programs. Or, it was necessary to develop a package that included the operating environment.

[Problems to be solved by the invention]

In the conventional operating environment for a machine language program in a personal computer, there is a problem that the memory address space is limited and a large program cannot be developed. Also, if some modules are changed after fixedly assigning an address to each module,
There is also the problem of lack of flexibility because the addresses of other modules also need to be changed.

However, if a virtual memory system is adopted for a small-scale system such as a personal computer using an 8-bit processor, the scale of the system becomes large, the cost becomes high, and the overhead by the operating system increases. There's a problem.

The present invention solves the above problems, provides an operating environment that enables efficient use of limited memory with a simple control mechanism and facilitates the development of an application system developed by an assembler or the like. Is intended.

[Means for solving problems]

 FIG. 1 shows a basic configuration example of the present invention.

In FIG. 1, reference numeral 10 is a processing unit composed of a CPU and a memory, 11 is an object consisting of a series of instruction codes or data groups, and management information necessary for its operation, 1
1A is an object management information section, 11B is an object body section, 12 is an object memory area in which objects are dynamically rearranged, 13 is a next object name storage section in which the name of an object to be executed is stored, and 14 is an object Is a main control unit for controlling the execution of a common routine, 15 is a common routine control unit for controlling the calling of a common routine,
6 is a common routine address table that stores the start address of the corner common routine corresponding to the request number,
Reference numeral 17 is a common routine section commonly used by each object and the main control section 14, 18 is an object search processing section for searching for an object and loading it into the object memory area 12 as necessary, 19 is a loader, 20
Is a garbage collector for collecting used areas in the object memory area 12, 21 is a message display processing section for displaying a message on the display, and 22 is A
A code conversion unit 23 for converting between the SCII code and the JIS code represents an external storage device such as a floppy disk.

In the present invention, an application system such as an educational software package is managed as a set of a plurality of objects 11 which are operation units. That is, when designing a system, the programs and data that make up the system are decomposed in advance, for example, in processing function units, and the divided individual elements are
It is an object 11.

The object 11 includes an object management information section 11A and an object body section 11B. The object management information unit 11A has the following information, for example.

 Size information Indicates the size (byte count) of the entire object.

Type information Indicates the type of the object such as a program type object (PTO) or a data type object (DTO).

Level information Indicates the priority order in terms of the degree of necessity of the object in the object memory area 12. For example, it provides information such as whether it is subject to garbage collection.

 Name length information Indicates the length (number of bytes) of the object name.

Object name information Indicates the object name given to identify the object.

Unique attribute information In addition to the above information, the object attribute information prepared as necessary is shown.

When the object 11 is a program type object (PTO), the machine language code is stored in the object body section 11B following the object management information section 11A, and the data type object (DT
In the case of O), data such as numerical values and characters are stored.

The main control unit 14 retrieves the object name set in the next object name storage unit 13 each time the execution of each object 11 is completed, and, via the common routine control unit 15,
Processing for calling the object search processing unit 18 in the common routine unit 17 is executed. Then, based on the address information of the object notified from the object search processing unit 18, the execution control is passed to the next object 11.

For example, if the object (PTO-1) sets the object name of the object (PTO-2) whose control is to be transferred next in the next object name storage unit 13, the execution of the object (PTO-1) ends. When the object (PTO
-2) is prepared, and execution control is passed to the object (PTO-2).

The common routine unit 17 is composed of a routine group that realizes processing functions that are used in general and processing functions related to hardware control. In addition to the message display processing unit 21 and the code conversion unit 22 shown by way of example, routines for providing various file input / output functions are prepared as needed.
A request number is assigned to each of these common routines, and the common routine address table 16 stores the address information of the common routine corresponding to the request number.

The common routine control unit 15 controls to call the common routine to which the request number is given, according to the designated request number.

The common routine section 17 is particularly provided with an object search processing section 18 as related to the present invention. The object search processing section 18 checks whether or not the object 11 having the specified object name exists in the object memory area 12 by referring to the object management information section 11A of each object. If there is a corresponding object 11,
The starting address of the object 11 is notified to the caller of the common routine control unit 15.

If the corresponding object 11 is not in the object memory area 12, the loader 19 is called to read the object memory area 1 from the external storage device 23.
The object 11 is loaded onto the upper part of the table 2 and its start address is notified to the caller. When loading,
If there is not a sufficient free (empty) area on the object memory area 12, the garbage collector 20 is called to collect an unnecessary area to secure the free area.

In addition, regardless of the execution control by the main control unit 14,
The program type object (PTO) can load the required data type object (DTO) forever.

When this data type object is used, for example, for managing image data displayed on a display, it is convenient because the object search processing unit 18 or the loader 19 can be used for data input / output from the external storage device 23. .

[Action]

According to the present invention, the application system is managed as the objects 11, and each object 11 is dynamically relocated to the object memory area 12 when execution is required. Only one object 11 is being executed at one time point, and other executed objects can be discarded from the object memory area 12 as necessary. Therefore, by increasing the number of objects,
You will be able to develop applied systems as much as you want.

When a new function needs to be added, a new object can be created, and the influence on the existing part of the application system can be reduced. Since the transfer of control of each object 11 is simplified, so-called combined debugging is almost unnecessary, and debugging can be facilitated. In addition, it is very easy for multiple people to proceed with development work in parallel, and the development period can be shortened.

〔Example〕

FIG. 2 shows an example of memory mapping according to one embodiment of the present invention, FIG. 3 shows an example of object control transfer according to one embodiment of the present invention, and FIG. 4 shows a processing explanatory diagram of one embodiment of the present invention.

The memory for a system having an 8-bit processor and an address space of 64 KB is used, for example, as shown in FIG.

In FIG. 2, 30 is a memory, 31 is a work area such as BASIC, 32 is a monitor area, 33 is a PTO area in the object memory area 12, 34 is a DTO area, and 35 is an interface area related to hardware control. .

In the monitor area 32 of the memory 30, the next object name storage 13, the main controller 14, the common routine controller 15, and the common routine address table 1 shown in FIG.
6, the common routine unit 17 is set.

As an application system area, an object memory area 12 is provided after a monitor area 32. In this embodiment, the object memory area 12 is a program type object PTO area 33 and a data type. -The DTO area 34 for objects is managed separately.

Figure 2 (b) shows three program type objects "PTO-1", "PTO-2", and "PTO-3".
And two data type objects "DTO-
1 ”and“ DTO-2 ”are loaded. The PTO state 33 and the DTO area 34 are sequentially used from the beginning, and the remaining areas are managed as free (empty) areas.

In the state of FIG. 2B, for example, the object PTO-3
Is completed, and the object PTO-4 is next specified. At this time, the size of the object RTO-4 is checked to see if a load area for the object PTO-4 can be secured from the free area of the PTO area 33. If the free area is small and cannot be secured, use the garbage collector 20 shown in FIG.
Objects that are no longer needed PTO according to level information
It is discarded from the area 33 and refilled. In this example, the object PTO-2 in FIG. 2B is discarded, and the object PTO-2 is displayed as shown in FIG.
-3 has been moved and object PTO-4 has been loaded. The object PTO-4 has a DTO area 34.
Then, the data type object DTO-3 is loaded.

Next, an example of control transfer of the program type object will be described with reference to FIG.

For example, it is assumed that control transfer is performed among the objects PTO-1 to PTO-7 in the order of to shown in FIG. The transfer of control between the objects is performed by the activation source object by setting the object name of the activated object in the next object name storage unit 13 shown in FIG. 1 before the end of execution. It is performed by the main control unit 14.

If there is a sufficient free area to simplify the explanation, each object will be expanded in the memory 30 as shown in FIG. 3B according to the control transfer of each object. . Garbage caused by lack of space
Unless the collection is performed, the object once loaded exists in the memory 30, so that it can be used without reloading when it is called again. Of course, each program type object must be relocatable in advance.

Next, an example of processing according to the embodiment of the present invention will be described with reference to FIG. (A) to (m) in the following explanation are
This corresponds to the processes (a) to (m) shown in FIG.

The main control unit 14 is, for example, (a) to (a) shown in FIG.
Process as in (c).

(a) From the next object name storage unit 13 shown in FIG.
Get the object name to be invoked next.

(b) The request number of the object search processing unit 18 is specified and the common routine control unit 15 is called. As a result, the object search processing unit 18 operates,
The start address of the object to be activated next is notified.

(c) The machine language code start address of the object 11 is calculated from the notified start address, and execution control is passed. When the execution of the object 11 is completed, the control is returned to the processing (a), and the processing is repeated.

The common routine control unit 15 is shown in, for example, FIG.
Process like (d) to (g).

(d) The request number is received from the request source by, for example, a predetermined register.

(e) From the common routine address table 16, obtain the start address of the common routine corresponding to the request number.

(f) to (g) Pass control to the start address and call the specified common routine. When the execution of the common routine is completed, control is returned to the request source. Object search processing unit 18 provided as one of common routines
Are processed as shown in (h) to (m) of FIG.

(h) With the specified object name, the object already loaded in the object memory area 12 is searched.

(i) It is determined whether or not the corresponding object exists in the object memory area 12. If it does not exist,
Control is transferred to process (k).

(j) Obtain the start address of the corresponding object in the object memory area 12 and notify the caller.

(k) If the object is not loaded, check the size of the object on the external storage device,
A free area of the object memory area 12 is secured. If it cannot be secured, the garbage collector 20 is called to expand the free area.

(l) By calling the loader 19, the object memory area 12 of the corresponding object is loaded.

(m) Rewrite the start address of the free area and transfer control to processing (j).

〔The invention's effect〕

As described above, according to the present invention, the application system is configured as a set of objects including its own management information and is dynamically arranged in the memory at the time when it is needed at the time of execution. It enables efficient use of. In particular, the control transfer structure is simple and the monitor area can be reduced, so it is suitable for a small-scale system used for personal use. In addition, since various data structures of the system can be handled in a unified manner by focusing on the commonality of their functions, they are highly expandable, flexible, and easy to design, develop, and improve. become.

[Brief description of drawings]

FIG. 1 is a basic configuration example of the present invention, FIG. 2 is a memory mapping example according to an embodiment of the present invention, FIG. 3 is an object control transfer example according to an embodiment of the present invention, and FIG. The process explanatory drawing of one Example of invention is shown. In the figure, 10 is a processing arrangement, 11 is an object, 11A is an object management information section, 11B is an object body section, 12 is an object memory area, 13 is a next object name storage section, 14 is a main control section, and 15 is a common routine. Control unit, 16 is a common routine address table, 17 is a common routine unit, 18 is an object search processing unit, 19 is a loader, 20 is a garbage collector,
21 is a message display processing unit, 22 is a code conversion unit, 2
Reference numeral 3 represents an external storage device.

Claims (1)

[Claims] 1. A data processing system comprising a central processing unit, a memory and an external storage device, which is an object (11) consisting of a series of instruction codes or data groups and management information necessary for its operation, The management information includes at least the size information of the object and the information of the object name for identifying the object, and is a memory area for the object dynamically relocated.
(12), the above objects (11) and the following main control unit (1
A predetermined object area commonly accessed from 4), and an object name identifying an object to be executed next is stored in the next object name storage unit (13) stored by the currently executing object (11). , The object memory area (12) is searched by the specified object name, and the object memory area is searched.
In (12), an object that returns the address information if the corresponding object exists, and loads the corresponding object from the external storage device and returns the address information if the corresponding object does not exist. A common routine that performs a prescribed procedure commonly prepared for the search processing unit (18) and the system and that includes the above-described object search processing unit (18) is determined in advance for each common routine. The common routine control part (15) that controls to call by the specified request number and the object (11) having the object name stored in the next object name storage part (13) when the execution of the currently executed object ends. The object search processing unit (18) is specified via the common routine control unit (15).
An object execution control method comprising: a main control unit (14) that obtains address information of the corresponding object by calling, and transfers execution control to the object (11).