JP2001265649A - Memory management method and device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a memory management method and device excellent in real-time performance and guaranteed in progress. SOLUTION: An object body is stored in a storage area 2, a handle referring to the object is stored in a storage area 3, and the largest global car number among the cars to which the object referring to the object belongs is recorded in the handle. I do. At the time of garbage collection, a handle set that refers to an object that is not collected as garbage is obtained, and either the mark or the moving process is assigned to the referenced object. Then, the handles belonging to the above set are moved to a car satisfying the reference source maximum car number or more, the object to which the movement processing is assigned is moved to an unused storage area, and the object to which the mark processing is assigned is marked. Retrieve unmarked objects and retrieve cars and trains from the smallest train.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION With the advent of a processing system called Java, the importance of a language processing system having a garbage collection (hereinafter, referred to as GC as necessary) from the Internet to home appliances has been increasing. In such a language, the execution speed of the GC becomes a problem, and a GC with a short interruption time is required. The present invention relates to a memory management method and apparatus which is excellent in real-time performance and capable of performing GC with a short interruption time, and which guarantees progress.

[0002]

2. Description of the Related Art Garbage collection (hereinafter referred to as GC) is to determine data existing in a storage area and not to be processed by an application again, and to make the storage area occupied by the data reusable. The technology to do. First, some technical terms will be described. The user's application is called a mutator. The mutator creates and changes data to be subjected to GC. Such data is called an object. Of the objects
Objects that are never processed by the mutator are called garbage. Objects can hold references to other objects. The variable that holds the reference is called the pointer variable.

As a conventional GC method, there is a method called a train algorithm. This is characterized in that the execution time of the mutator is interrupted for a short time, the interruption time is suppressed to a substantially fixed time, and an arbitrary structure including an object and a reference can be set as a GC target. The train algorithm is a GC that utilizes divided management of a storage area structured in two stages and movement of an object between partial storage areas. Hereinafter, the above-described conventional GC processing will be described. In the train algorithm, a car obtained by dividing a storage area into fixed-size storage areas consisting of continuous addresses is called a car. Objects must belong to one of the cars. Therefore, the maximum area length of the object is determined by the area length of the car. A set with cars as elements is called a train. Two or more trains must be provided in the system. further,
The trains must be sparse, that is, "do not have a common car."

FIG. 9 shows the configuration of a storage area composed of cars and trains. The total order of the trains is determined, and the order number of each of the trains 1 to m is called a train number.
The cars in each train 1-m are also ordered and each car 1
The ordinal number of n is called a car number. Although the car numbers included in a certain train are all different, cars having duplicate car numbers may exist if the trains are different.
Then the cars of all trains are ordered as follows. The size of the car in the train is determined by the car number. The size of the cars included in different trains is determined by the train number. Based on this, a set of a train number and a car number is called a global car number. Global car numbers have a full order.

A set of pointer variables called a remember set is defined for each car. The element of the member set records a storage address on another car having a higher global car number or a storage address of a root, which refers to an object existing in this car. FIG. 10 shows the relationship between the reference and the pointer variable of the member set. As shown in the drawing, a car 1 defines a member set 1. Here, it is assumed that the object k of the car k having the global car number larger than the car 1 refers to the object 1 of the car 1 (the pointer variable of the object k of the car k points to the object 1 of the car 1). Then, the element of the member set 1 (pointer variable 1) contains the car k
The storage address of the object k is stored. When the object 1 of the car 1 is referred to from the route, the storage address of the route is recorded in the element 1 of the member set 1.

In the train algorithm, GC processing is performed as follows using the above-described car, train, and member set. Note that the GC process is repeatedly performed during execution of the mutator. 1) Suspend execution of the mutator over all GC processes. 2) Check if the minimum train is referenced by the root or another train. If not pointed to by anyone, collect all cars in the minimum train and the minimum train itself as a target for reuse, and proceed to step 7) described later, while if it is referenced from somewhere, the following Proceed to the procedure. 3) Scan the member set of the smallest car, and (a) copy the object referenced from the root to any car in any train except the smallest train. (B) Copy an object that is not referenced from the root but is referenced by another car to an arbitrary reference source car or a car having a car number higher than the reference source. After the copying is completed, the pointer variables pointing to the copy source object are all rewritten so as to point to the copy destination object. Then, the storage area occupied by the copy source object is collected. This is called object movement processing.

4) The storage address of a pointer variable in another car pointing to this object is added to the remember set of the destination car and recorded. However, the car number of the car in which the pointer variable pointing to the moved object exists is limited to the car number larger than the car number of the movement destination. 5) All the objects belonging to the smallest car and reachable from the moved object are applied to step (3) (b) and moved to each car. 6) As a result, only objects that cannot be moved to the smallest car or garbage remain. When all objects are garbage, after retrieving them, retrieve the car from the minimal train. If it cannot be collected, leave the smallest car as it is. If no cars are included in the minimum train, the minimum train is removed from the set of the entire train. 7) Resume execution of the mutator.

In order to perform the GC processing of the train algorithm, a support processing for the train algorithm is required as a part of the processing of the mutator. This is called a write barrier process. The write barrier processing is defined as “a mutator stores a reference to an object in a car Y different from the car X to which the object belongs, and only when the car Y is larger than the car X, A process of adding a pointer variable holding a storage address on the car Y to the set is referred to.

[0009]

It is an important requirement that the garbage can be collected within a finite time, and therefore the progress is important. Here, the term "progressiveness" is defined as follows. Progress is said to occur when one or more garbage is collected by the GC process, or one or more objects have moved from the minimum train.
That is, if there is progress, it is guaranteed that the minimum train will be collected someday. This is synonymous with that any car will be subject to GC someday. It is an important requirement for the GC system that garbage can be collected within a finite time.

The problems with the above-described train algorithm are listed below. 1) Since progress cannot be guaranteed, there is no guarantee that garbage will be collected within a finite time. Progress cannot be guaranteed in the following situations. In a situation in which there is no garbage in the smallest car and all objects cannot be moved, the progress is lost because the smallest car cannot be collected. FIG. 11 shows an example. As shown in the figure, when the object of the minimum car N0 cannot be moved, the minimum car cannot be collected. In a situation where both of the following two conditions are satisfied, progress cannot be guaranteed. There is a cyclic object structure extending over a plurality of cars including the smallest car, and the storage area required for the entire object structure is larger than the size of the car. -The object structure is not pointed to by other objects in the train, but is referenced from the root in a car other than the smallest car.

FIG. 12 shows an example. As shown in the figure, the object 1 of the smallest car 1 is the object k of the car k
And the object 1 has a cyclic structure in which the object k refers to the object k1 of the car k. In this object structure, the object k is not referred to from other trains but is referred to from the root. If the storage area required for the entire object structure is larger than the size of the car as described above, the progress of the car cannot be guaranteed because the smallest car cannot be collected. .

2) It is difficult to restrict the size of the member set in advance. For example, as shown in FIG. 13, when there are a large number of pointer variables in another car pointing to a certain object, the member set for recording the variables becomes very large. In this case, the following problem occurs. The area for recording the member set increases. The time required for updating the pointer variables recorded in the member set when the object is moved is proportional to the number of pointer variables, and it cannot be guaranteed that the GC processing will be completed within a predetermined interruption time.

3) When garbage forms a reference structure that crosses cars, garbage cannot be reliably collected until the maximum car number of an object included in the structure becomes a GC target. Therefore, useless work of copying garbage may occur. FIG. 14 is an example,
In the case of a reference structure that crosses cars so that the object 1 of the smallest car 1 is referenced by the object of the car k and the object k of the car k is referenced by the object of the car m, the largest car number m becomes a GC target. Until, garbage cannot be collected reliably. 4) For example, as shown in FIG. 15, an object having a size that does not fit in a car cannot be handled by the train algorithm. The present invention has been made in order to solve the above-described problems of the related art, and the object thereof is to:
An object of the present invention is to provide a memory management method and apparatus which is excellent in real-time performance and can ensure progress, which can surely complete GC within a predetermined time.

[0014]

FIG. 1 is a diagram showing an outline of the present invention. As shown in FIG. 1B, in the present invention, the storage area is divided into a car / train management area 1, an object storage area 2, and an area 3 for storing a handle, and the object body is divided into the above. An object 3 is stored in the object storage area 2, a handle for referring to the object is stored in the area 3 for storing the handle, and the largest global car among the cars to which the object referring to the handle belongs is stored in the handle. Record the number. Also,
In the car / train management area 1, each handle is associated with a car and a train. Then, at the time of garbage collection (GC), the following processing is performed as shown in FIG. (a) A handle set that refers to an object that is not collected as garbage is obtained from a reference source of a handle belonging to the minimum train, and one of mark processing and moving processing is assigned to the object that is not collected as garbage. (b) The handle belonging to the above handle set is moved to a car that satisfies the reference source maximum car number or more, and the object to which the movement processing is assigned is moved to an unused storage area equal to or longer than the area length of the object. Mark assigned objects. (c) Collect unmarked objects as garbage, and collect cars and trains from the smallest train. In the present invention, since the GC processing is performed as described above, the GC can be always completed within a predetermined interruption time, and the GC can always delete one or more cars. . Therefore, the real-time property is excellent, and the progress property can be guaranteed.

The present invention can also be configured as follows. (1) The assignment of the mark processing and the movement processing is performed based on a restriction not to exceed a predetermined interruption time of the mutator. (2) When assigning either the mark processing or the movement processing, the processing A for assigning the mark or the movement processing to the object referenced from the root
And a process B of selecting n cars from the minimum train and assigning a mark or a movement process to an object of the selected car, and a process A and a process B according to a predetermined interruption time of the mutator. Perform selectively.

[0016]

Embodiments of the present invention will be described below. The GC processing of the present invention is based on the following mutator execution environment. All objects are rewritten using indirect references,
A read process is performed. There is no direct reference to the object in the mutator pointer variable. In the following description, an indirect reference is called a handle. The handle of the object belonging to the car is registered in the aforementioned member set. The relationship between the handle and the object is as shown in FIG. That is, as shown in FIG. 1A, a storage area for managing a car and a train, a storage area for storing an object body, and an area for storing a handle are provided, and an object is referenced via the handle. I do. Also, as described above, there is no physical object in the car. The handle has the address of the own object, the car, and the train number (the largest car and train number referred to by the object referencing the own object) as shown in FIG. Point to the handle. The handle address can be moved. In that case, the information in the management area is rewritten. During the write barrier processing by the mutator, the car / train number of the handle is rewritten.

An object currently being processed may not be able to move. Objects with large and small area lengths are mixed. The allowable interruption time is determined before execution, and it is requested that the GC process is always completed within the interruption time.

In this embodiment, the mutator performs the following GC support processing during execution. Structure of Remember Set In the remember set, the handle of the object belonging to the car is registered as described above, instead of the address of the reference pointer variable. In the registered handle, the largest global car number among the cars to which the object referring to the handle belongs is recorded. The car number recorded on the handle is referred to as a reference source maximum car number. Write barrier processing When storing a reference to a handle pointing to another object in an object, if the reference global car number of the handle is smaller than the global car number of the car to which the object belongs, the reference global car number of the handle is Set to a car number higher than the global car number of the car to which

FIGS. 3 and 4 show the GC processing procedure of this embodiment. Hereinafter, the GC processing of this embodiment will be described with reference to FIGS. In the following description, procedure 3) [Process A] and procedure 4) [Process B] are in no particular order.
N and c appearing in these procedures are determined so that the upper limit of the total time spent on the work estimated from [Process A] and [Process B] is smaller than the interruption time. Further, the following steps S1, S2,... Are the step numbers assigned to FIG. 3 and FIG. Further, in addition to the conventional route, a reference from a non-minimum train to a minimum train is generally defined as a “pseudo route”, and when emphasizing the meaning as a set, it is referred to as a “pseudo route set”. 1) Simultaneously with the start of the GC processing, the execution of the mutator is interrupted (step S1 in FIG. 3). 2) It is checked whether the minimum train is referred to from the root or another train (whether the minimum train is referred to from a pseudo route) (step S2). If not pointed out by anybody, all cars in the minimum train and the minimum train itself are collected for reuse (step S).
3), proceed to the procedure 10) (step S11) described later,
On the other hand, if it is referenced from somewhere, the procedure proceeds to the following procedure.

3) Allocate a process to the object referenced from the pseudo root. This is called process A. (A) A non-empty subset C of the handle set belonging to the minimum train and referred to by the pseudo route is determined (step S4). C only needs to include at least one handle referred to from the actual route. (B) Assignment is performed to all objects referenced by C, whether to perform a mark process or a move process (step S5). For example, as shown in FIG. 5, the handles H1, H2, H3 of the cars 1 and 2 of the smallest train.
Is referred to from the root R1 and the root R2 (which may or may not be a pseudo root), a subset C is determined as shown in FIG. Assignment is made to the objects Ob1, Ob2, and Ob3 as to which of “movement processing” and “mark processing” is to be performed. An object to which either “move processing” or “mark processing” is assigned is not collected as garbage, but an object to which “move processing” is assigned is an unused storage area having an object area length or more as described later. Moved to In addition,
The ratio between "move processing" and "mark processing" can be freely selected. Mark processing requires less work than moving processing, so if priority is given to mark processing, multiple cars including the smallest car can be used. Can be subject to GC.

4) (n + 1) cars are selected from the minimum train, and processing is assigned to all objects. This is called [Processing B]. (A) From the smallest train, starting from the smallest car (n +
1) Cars, that is, cars with car numbers No to Nn are selected (step S6). Here, n is an integer of 0 or more. (B) Collect all indirect references from cars larger than Nn from the union of the remembered sets of cars from No to Nn. This set is defined as R (step S7). (C) Assignment is performed to all objects existing in the car from No to Nn to perform either the mark processing or the movement processing (step S8). For example,
As shown in FIG. 6, car 1, car 2, and car 3 are selected from the cars belonging to the minimum train. Then, indirect references from the cars larger than 3 are collected from the union of the remembered sets of the cars 1 to 3, and are set as the union R as shown in FIG. Then, an assignment is made to all the objects Ob1 to Ob4 existing in the car 1, the car 2 and the car 3 as to which of the "moving processing" and the "marking processing" is to be performed.

5) Find the union M of R (a set of indirect references from cars larger than Nn) and C (a set of handles referenced from the root), and determine the reachability from M by the reference relationship. Based on this, a transitive closure set T composed of handles belonging to any of the cars No. to Nn is obtained. Here, “reachability from M” means a connection from M by a reference relationship, and the “transitive closure set T” has a reference relationship with M when following the reference relationship from M. A set of handles belonging to cars No. to Nn. They are not subject to garbage.

6) The handle included in the transitive closure set T is moved to a car satisfying the reference source maximum car number or more (step S9). That is, since the maximum car and train number can be obtained from the car and the train number of the handle, the maximum car number of the reference source is obtained by using this, and the handle that is not a garbage target (the handle included in the transitive closure set T)
To the reference source maximum car number or higher. However, only when this handle is referenced from the route and the car specified by the reference source maximum car number belongs to the minimum train, the handle is moved to any car in any train other than the minimum train . Even if the handle is moved, the object itself does not move, but the object referred to by the handle does not change. Therefore, the object is logically moved to another car or train. After the handle is moved, if the pointer variable held by the object referenced by the handle includes an element (handle) of the transitive closure set T, the reference source maximum car number of the element is updated as necessary. This is a process for reflecting the current state in the reference source maximum car number. The above processing is applied to all the handles included in T.

7) If the object referred to by the moved handle is determined to perform only the "mark processing", a mark is set on the object. On the other hand, if the object is set to move, the object is moved to an unused storage area having a length equal to or longer than the area length of the object as described above. By moving the object, it becomes possible to secure an integrated area on the storage area. 8) Of the objects left in the cars No. N to Nn, unmarked objects are determined as garbage and collected. 9) Remove Nn from car number No from the minimum train. If there is no car included in the minimum train, the minimum train is removed from the entire set of trains (step S10). 10) Restart the execution of the mutator (step S1)
1).

The above-described GC processing has the following advantages over the conventional example, and guarantees that the minimum train will be collected someday. That is, progress can be guaranteed. Since a handle that is an indirect reference is registered in the member set, the element in the member set for multiple references to the same object can be made unique.
That is, even when many objects refer to an object, it is not necessary to have a plurality of pointer variables in the member set as described in the conventional example, and only one handle may be used as an element in the member set. For this reason, it can be guaranteed that the remember set of a car does not exceed the number of objects belonging to the car. As a result, it is possible to avoid an increase in the required area and the scanning time due to the enlargement of the member set. In addition, there is no need to specially handle objects referenced by many pointer variables.

Since the object does not physically exist in the car, it is not necessary to consider where the object exists in the storage area. Therefore, the movement of the object is not an essential process for the GC process. In other words, the object can be flexibly moved, for example, the object that is not allowed to move and the movable object moves to an unused area. By deciding not to move a large object at all times, the same handling as a small object can be performed. The process of selecting garbage from the objects belonging to the car is performed using the movement of the object or the mark of the object. Therefore, the ratio between the mark processing and the movement processing can be freely selected without exceeding a predetermined interruption time. In general, the mark processing requires a smaller amount of work than the movement processing.
Can be targeted. As a result, the garbage found by the GC increases, and it is realized that they are not moved wastefully. When the GC process is completed, no mutator readable / writable handle remains in the area of consecutive car numbers including the minimum car. Therefore, it is possible to always delete one or more cars by one GC process. At least one of the objects referenced from the root belongs to another train by the mark processing or the movement processing.

Next, an example of the configuration of a memory management device that performs the above-described GC processing will be described. FIG. 7 is a diagram showing the overall configuration of the memory management device of the present embodiment, and FIG. 8 is a diagram showing the detailed configuration of a continuous execution device for the object mark moving process in FIG. In the figure, the arrow indicates the flow of information, the portion surrounded by a rectangle is processing means, the portion surrounded by an ellipse is information,
Show data. The memory management device shown in FIGS.
It can be realized by a normal computer system having a PU, a memory, an external storage device, an input / output device, and the like. A program for performing the GC processing of the present embodiment is stored in the external storage device and the like. Is read into the memory, and the GC process is performed. As shown in FIG. 7, the memory management device of the present embodiment is composed of four elements. In the figure, the processing pseudo route selection means 11 outputs a subset of handles pointed from the pseudo route to be processed from the set of all handles pointed from the pseudo route.

The assigning means 12 for the object mark moving process performs processing based on the restriction of the mutator interruption time given a priori, a set of all handles belonging (managed) belonging to the smallest car, and a subset of the pseudo route. A mark and a movement process are assigned to all the target objects. Further, this means 12 can request the processing route selecting means 11 to add a handle. The object mark moving process continuous execution means 13 will be described in more detail with reference to FIG.
The movement processing assignment and the subset of the pseudo route are read, and the marking and movement processing are performed on each object as described above. When the processing in the continuous execution means 13 is completed, the continuous execution means 13 transmits a completion notification to the car and train deletion means 14. car,
Upon receiving the completion notification, the train deletion unit 14 deletes the minimum car. If there is no car in the minimum train, the minimum train is continuously deleted.

As shown in FIG. 8, the continuous execution means 13 for the object mark moving process is composed of five elements. The merger 21 reads the minimum car remember set and the root subset, and outputs the union of them. The output union becomes the initial value of the operation handle. The handle reading means 22 reads 1 from the set of operation handles.
One handle is read, and the handle information described in the handle and the object information of the object pointed to by the handle are obtained.

The above-mentioned handle information is sent to the updating unit 23 for the assigned global car number and the reference source global car number. The updating unit 23 of the belonging global car number and the reference source global car number searches for a car suitable for the handle to move, and updates information of the belonging global car number of the handle and the reference source global car number. Object movement / mark processing means 24
Reads the object information and the assignment of the mark and movement of the object to each object, and actually executes the mark or movement processing of the object. Pointer writing means 2 inside the object
5 adds a handle stored in a pointer variable existing inside the object from the object information to an operation handle set output by the merger 21.

Next, the GC by the memory management device of this embodiment
The processing will be described. First, as shown in FIG. 2, the storage area is divided into an area for car and train management, an area for storing object bodies, and an area for storing handles. When a mutator (not shown) newly generates an object, the main body of the object is allocated in a storage area for the object. In addition, a handle that refers to the object is stored in a handle storage area. The secured handle will be recorded on any car. At this time, the smallest car may be divided into a plurality of cars. Thereafter, the storage address of the handle is passed to the mutator process. The upper limit of the number of handles that can be included in the smallest car is to determine the maximum number of handles that does not exceed a predetermined interruption time, assuming that mark processing is applied to all objects in this car. Trigger GC processing by number.

When the GC process starts, as described above, the processing route selection means 11 outputs a subset of the handles pointed to by the route to be processed from the set of all handles pointed to by the route. The assigning means 12 for the object mark moving process assigns all the objects to be processed from the constraints on the mutator interruption time, the set of all handles belonging to (managed by) the smallest car, and the subset of the pseudo route. On the other hand, a mark and a movement process are assigned. As shown in FIG. 8, the continuous execution means 13 of the mark moving process of the object reads the member set of the minimum car, the mark to each object, the allocation of the moving process, and the subset of the pseudo route, and On the other hand, the mark and move processing is performed as described above.

That is, as described with reference to FIGS. 3 and 4, the handle is moved to a car having a reference source maximum car number or more recorded on the handle. If the upper limit of the number of handles that can be registered in the car is exceeded (this may be arbitrarily determined), the handle is registered in the car having the next larger car number. If movement processing has been assigned to the object referenced by this handle, an area equal to or larger than the object size is assigned to an unused area in the object area, and the object is moved there. When the GC processing is completed, the car / train deletion unit 14 deletes the minimum car, and if there is no car in the minimum train, the car and train deletion unit 14 continuously deletes the minimum train. Then, the area occupied by the garbage remaining in the object area is collected and reused as an unused area.

[0034]

As described above, according to the present invention, the following effects can be obtained. (1) The GC can always be completed within a predetermined interruption time, and the GC can always delete one or more cars. Therefore, the real-time property is excellent, and the progress property is guaranteed. (2) Only one element in the member set for multiple references to the same object can be made. For this reason, it is possible to avoid an increase in the required area and the scanning time due to the enlargement of the member set. (3) It is possible to flexibly move an object, for example, moving an object that is not allowed to move to an unused area while leaving an object that is not allowed to move. (4) Since the process of selecting garbage from the objects belonging to the car is performed using the movement of the object or the mark of the object, the ratio of the mark processing to the movement processing is appropriately selected to include the minimum car. A plurality of cars can be set as GC targets. As a result,
The garbage found by the GC increases and it can be realized that they are not moved wastefully.

[Brief description of the drawings]

FIG. 1 is a diagram showing an outline of the present invention.

FIG. 2 is a diagram illustrating a reference relationship among a storage area, an object, and a handle in the embodiment of the present invention.

FIG. 3 is a diagram showing a GC processing procedure (1) of the embodiment.

FIG. 4 is a diagram illustrating a GC processing procedure (2) of the present embodiment.

FIG. 5 is a diagram illustrating a subset C of handles referred to from a pseudo route.

FIG. 6 is a diagram illustrating a set R of indirect references from a car larger than Nn in a union of remembered sets of cars from No to Nn.

FIG. 7 is a diagram illustrating an overall configuration of a memory management device according to the present embodiment.

FIG. 8 is a diagram illustrating a configuration of a continuous execution unit of a mark moving process of an object according to the present embodiment.

FIG. 9 is a diagram showing an inclusion relationship between a car and a train.

FIG. 10 is a diagram showing a relationship between elements of a member set and references.

FIG. 11 is a diagram illustrating a situation (1) in which progress is not guaranteed.

FIG. 12 is a diagram illustrating a situation (2) in which progress is not guaranteed.

FIG. 13 is a diagram illustrating a situation in which many pointer variables are registered in a member set.

FIG. 14 is a diagram illustrating a situation where a large number of GCs are required for collection.

FIG. 15 is a diagram illustrating a situation where an object does not fit in a car.

[Explanation of symbols]

11 Process pseudo route selecting means 12 Object mark moving processing assigning means 13 Object mark moving processing continuous executing means 14 Car and train deleting means 21 Merger 22 Handle reading means 23 Affiliated global car number and reference source global car number Update means 24 object movement / mark processing means 25 pointer writing means inside object

Claims (13)

[Claims] 1. A memory management method for performing garbage collection for a language processing system having a function of accessing an object by using indirect reference, wherein a storage area is a car, a train management area, and an object storage area. An object is divided into an area for storing a handle, an object body is stored in the storage area for the object, a handle for referring to the object is stored in the area for storing the handle, and the handle is stored in the handle. Record the largest global car number of the car to which the referencing object belongs, and in the garbage collection process, obtain a handle set that refers to the object that is not collected as garbage from the reference source of the handle belonging to the smallest train, The handle belonging to the handle set is referred to as the reference source maximum car number. A memory management method, comprising: moving to a car that satisfies at least the number of vehicles, and collecting a car and a train to be garbage collected from the smallest train. 2. At the time of garbage collection, one of a mark process and a move process is assigned to an object that is not collected as garbage, and the object to which the move process is assigned is moved to an unused storage area equal to or longer than the area length of the object. , Mark objects that have been marked for marking,
2. The memory management method according to claim 1, wherein unmarked objects are collected as garbage. 3. The memory management method according to claim 2, wherein the assignment of the mark processing and the movement processing is performed based on a constraint that a predetermined interruption time of the mutator is not exceeded. 4. When allocating either a mark process or a move process, a process A for allocating a mark or a move process to an object referenced from a route, and selecting n cars from the minimum train and selecting the selected car. 3. A process B for allocating a mark or a movement process to an object of a car that has been set, and the processes A and B are selectively performed according to a predetermined interruption time of the mutator. 3. Memory management method of 3. 5. A memory management device for performing garbage collection on a language processing system having a function of accessing an object using indirect reference, wherein a storage area includes a car, a train management area, and an object body. An object storage area for storing and a handle storage area for storing a handle are provided. A handle for referring to an object is stored in the area for storing the handle, and the handle is referred to in the handle. The garbage collection processing means records the largest global car number of the car to which the object belongs, and the garbage collection processing means a handle set that refers to an object that is not collected as garbage from a reference source of a handle belonging to the smallest train in the garbage collection processing And the handle belonging to the handle set A memory management device for transferring a dollar to a car satisfying a reference source maximum car number or more, and collecting a car and a train targeted for garbage collection from a minimum train. 6. The garbage collection processing means includes an object mark / move processing assignment means. The object mark / move processing assignment means assigns a mark processing or an object not to be subjected to garbage collection in the garbage collection. The garbage collection processing means allocates any of the movement processing, moves the object to which the movement processing is allocated to an unused storage area equal to or longer than the area length of the object, and marks the object to which the mark processing is allocated. 6. The memory management device according to claim 5, further comprising: collecting unmarked objects as garbage. 7. The mark / move processing assigning means assigns the mark processing and the movement processing under a constraint not to exceed a predetermined interruption time of the mutator. The memory management method according to claim 6. 8. The method according to claim 1, wherein the assigning means for the mark / move processing of the object includes a processing A for assigning a mark or a move processing to the object referenced from the root when assigning either the mark processing or the move processing. A process B in which n cars are selected from the train and a mark or movement process is assigned to an object of the selected car, and processes A and B are selectively performed according to a predetermined mutator interruption time. 8. The memory management device according to claim 6, wherein the memory management is performed. 9. A recording medium storing a memory management program for performing garbage collection for a language processing system having a function of accessing an object using indirect reference, wherein the storage area is a car and a train management area. , An object storage area, and an area for storing a handle, an object body is stored in the object storage area, and a handle for referring to an object is stored in the area for storing the handle. The largest global car number of the car to which the object referring to the handle belongs is recorded in the handle, and the garbage collection process executes the garbage collection process from the handle reference belonging to the smallest train as a garbage. Find a set of handles that refer to objects that will not be reclaimed A storage medium storing a memory management program, wherein a handle belonging to the handle set is moved to a car that satisfies the reference source maximum car number or more, and a garbage collection target car and a train are collected from a minimum train. 10. The memory management program assigns one of a mark process and a move process to an object that is not a target of garbage collection at the time of garbage collection, and sets the object to which the move process is assigned to an object length equal to or longer than the object area length. To an unused storage area, and mark the objects to which mark processing has been assigned,
10. The storage medium according to claim 9, wherein unmarked objects are collected as garbage. 11. The memory management program according to claim 10, wherein the memory management program performs the assignment of the mark processing and the movement processing on the basis of a restriction not to exceed a predetermined interruption time of the mutator. A storage medium on which a program is recorded. Memory management method. 12. The memory management program, when allocating any one of a mark process and a move process, a process A for allocating a mark or a move process to an object referred to from a root, and n cards from a minimum train. And assigning a mark or a moving process to the object of the selected car
12. The storage medium according to claim 10, wherein the processing A and the processing B are selectively performed according to a predetermined interruption time of the mutator. 13. A memory management program for performing garbage collection for a language processing system having a function of accessing an object using indirect reference, wherein the storage area is a car, a train management area, and an object storage area. An object is divided into an area for storing a handle, an object body is stored in the storage area for the object, a handle for referring to the object is stored in the area for storing the handle, and the handle is stored in the handle. Record the largest global car number of the car to which the referencing object belongs, and the memory management program refers to the object that is not collected as garbage from the reference source of the handle belonging to the minimum train at the time of garbage collection processing A set of handles to be A memory management program characterized by moving a handle belonging to a car belonging to a maximum car number equal to or greater than a reference source maximum car number, and collecting a car and a train to be garbage collected from the smallest train.