JP2017162364A - Allocation device - Google Patents

Abstract

PURPOSE: To provide an allocation device capable of suppressing increase of processing load and preventing segmentation of a free space, in allocation of a continuous memory region.CONSTITUTION: A continuous memory region, where a plurality of unit memory regions in a physical memory is juxtaposed sequentially and continuously, is allocated for a plurality of types of processing. For one type of processing among the plurality of types of processing, a first allocation memory region is allocated from one end part of the continuous memory region, and during execution of the one processing, for the other types of processing, a second allocation memory region is allocated from the other end part of the continuous memory region.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an allocation device that allocates a memory area to a plurality of processes.

  When executing processing that requires high processing performance, such as video playback, processing can be performed using dedicated hardware in order to reduce the load on the OS (Operation System) and increase the processing speed. Are known. Since the mechanism of the virtual memory of the OS cannot be used from hardware, it is necessary to secure a continuous memory area for the processing in the physical memory when performing such processing.

  In products using embedded systems, the memory capacity is often not sufficient. Therefore, in order to secure a continuous memory area, it is necessary to prepare a dedicated memory area different from the memory area managed by the OS when the system is started. For example, in the case of moving image reproduction, a memory area having the size of the maximum moving image material necessary for product specifications is secured.

  It may be necessary to perform a plurality of processes simultaneously using such a dedicated memory area. For example, when playing different moving images on two screens, memory areas corresponding to the required size are allocated in order from the top (for example, the minimum address) of the prepared dedicated memory area. At that time, when a plurality of types of moving images are continuously played back, fragmentation occurs depending on the order of the moving images to be played back, and a continuous free space cannot be secured sufficiently. Considering fragmentation, it may be possible to prepare a dedicated memory area of a large size in advance, but in this case, the memory area that can be used by the OS becomes small.

  As a method of suppressing the occurrence of fragmentation, in an information recording / reproducing apparatus for recording program information on a hard disk, when an empty area occurs in the recording area, the program information recorded in the area following the empty area is moved to the empty area. A technique has been proposed in which empty areas are not subdivided even when recording / deletion of program information is repeated (for example, Patent Document 1).

JP 2005-354436 A

  In the above-described conventional technology, there is a problem that processing is burdened by the amount of processing for moving recorded information to an empty area. Unlike moving the recorded area when free space occurs on the hard disk, the process is temporarily suspended to move the continuous memory area allocated to the process currently being executed, such as movie playback. Must.

  The problem to be solved by the present invention is, for example, the problem of preventing subdivision of free areas while suppressing an increase in processing load that occurs in the above-described conventional technology.

  The invention according to claim 1 is an allocating device that allocates, to a plurality of processes, a continuous memory area in which a plurality of unit memory areas in a physical memory are sequentially juxtaposed, and one of the plurality of processes The first allocated memory area is allocated from one end of the continuous memory area for the process of (2), and the second allocated memory area is allocated to the other process during execution of the first process. An allocating unit that is allocated from the other end is provided.

  The invention according to claim 5 is a memory area allocating method in an allocating apparatus that allocates a continuous memory area in which a plurality of unit memory areas in a physical memory are sequentially arranged in parallel to a plurality of processes. , Causing the assigning means to assign a first assigned memory area to one of the plurality of processes from one end of the continuous memory area; and causing the assigning means to execute the first process. And allocating the second allocated memory area to the other process from the other end of the continuous memory area.

  The invention according to claim 8 is a program for allocating a continuous memory area in which a plurality of unit memory areas in a physical memory are sequentially arranged in parallel to a plurality of processes, and A step of allocating a first allocated memory area from one end of the continuous memory area to one of the processes, and a second allocated memory area to another process during execution of the first process Allocating from the other end of the continuous memory area.

  The invention according to claim 9 is a recording medium for recording a program for allocating a continuous memory area in which a plurality of unit memory areas in a physical memory are sequentially juxtaposed to a plurality of processes. The program allocates a first allocated memory area to one of the plurality of processes from one end of the continuous memory area to the computer, and another process during the execution of the first process. Allocating the second allocated memory area from the other end of the continuous memory area.

It is a block diagram which shows the structure of a moving image reproduction system. 3 is a diagram showing a configuration of a continuous memory area management module 22. FIG. It is a figure which shows typically the memory 12 and the continuous memory area | region CM. It is a figure which shows typically allocation of the 1st and 2nd allocation memory area to the continuous memory area CM. It is a figure which shows typically the example at the time of assigning a memory area in order from the head position.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following embodiment, a case will be described in which the assigning device of the present invention is applied to a moving image reproduction system that reproduces moving images separately and in parallel on two displays.

  The moving image reproduction system 10 includes a control unit 11, a memory 12, a hardware decoder 13, a first display 14 and a second display 15.

  The moving image reproduction system 10 receives a supply of moving image data VD from the outside, and performs a process of reproducing a moving image on the first display 14 or the second display 15. The moving image data VD includes, for example, moving image data stored in a USB memory, moving image data obtained by receiving digital terrestrial broadcasting, and moving image data obtained from a communication terminal such as a smartphone by a mirror link function, and corresponding to each It is compressed (encoded) in the format.

  The moving image reproduction system 10 is configured to be able to perform a plurality of types of moving image reproduction processes in parallel using the first display 14 and the second display 15. For example, video playback based on video data read from a USB memory (hereinafter referred to as USB video playback), video playback based on video data obtained by receiving a terrestrial digital broadcast (hereinafter referred to as terrestrial digital playback), and One of the moving image reproductions based on the moving image data obtained by the mirror link (hereinafter referred to as mirror link reproduction) is performed on the first display 14 while the other one is performed on the second display 15 in parallel. Is possible. Note that these moving image playback processes are hardware processes performed by the hardware decoder 13.

  The control unit 11 is configured by, for example, a CPU (Central Processing Unit) and includes a moving image reproduction application module 21 and a continuous memory area management module 22. The moving image playback application module 21 and the continuous memory area management module 22 are formed by the operation system operating in response to execution of an application program (not shown).

  The moving image reproduction application module 21 supplies a decode request DR requesting to decode the moving image data VD to the hardware decoder 13 via the line L1. In addition, the video playback application module 21 issues a memory allocation request for requesting to allocate a memory area (hereinafter referred to as an allocated memory area) to be allocated as a development destination of data for video playback processing in the continuous memory area CM in the memory 12. This is supplied to the continuous memory area management module 22.

  The continuous memory area management module 22 corresponds to an example of an allocation apparatus according to the present invention. As illustrated in FIG. 2, the continuous memory area management module 22 includes an allocation unit 31, an acquisition unit 32, and a determination unit 33.

  The allocation unit 31 is configured so that the continuous memory area management module 22 has a continuous memory area for moving image reproduction processing in the memory 12 that is bidirectionally connected to the control unit 11 via the line L2 in response to the start of the moving image reproduction system 10. A process for securing the CM is performed. As shown in FIG. 3, the continuous memory area CM includes a memory area in which a plurality of unit memory areas UM are sequentially arranged side by side.

  Further, the allocation unit 31 allocates a memory area to which the video data VD decoded by the hardware decoder 13 is expanded in the continuous memory area CM in response to a memory allocation request from the video playback application module 21. Process. At that time, the allocating unit 31 allocates a first allocated memory area from one end of the continuous memory area CM to one of a plurality of processes (moving image reproduction processes) in the continuous memory area CM. During execution of the first process, the second allocated memory area is allocated to the other processes from the other end of the continuous memory area CM.

  The continuous memory area CM is a memory area in which unit memory areas are successively arranged in order (for example, in the order of addresses). Accordingly, one end and the other end of the continuous memory area CM indicate, for example, the minimum address and the maximum address in the continuous memory area CM. When one of USB video playback, terrestrial digital playback, and mirror link playback is being played on the first display 14 and another type of video playback is to be performed on the second display 15, the allocating unit 31 has a continuous memory area. The first allocated memory area is allocated from the smallest address in the CM, and the second allocated memory area is allocated from the largest address in the continuous memory area CM.

  The acquisition unit 32 performs a process of acquiring memory information indicating a memory amount of a memory area necessary for each of the plurality of types of moving image reproduction processes. The memory area necessary for each of the moving image reproduction processes (hereinafter referred to as “necessary memory area”) is a memory area of the maximum size assumed to be used in the moving image reproduction process. For example, the required memory area for USB video playback is 40 MB, the required memory area for terrestrial digital playback is 32 MB, and the required memory area for mirror link playback is 16 MB.

  The allocating unit 31 sets the continuous memory area CM in the memory 12 based on the necessary memory area information acquired by the acquiring unit 32. Specifically, the allocation unit 31 secures a continuous memory area having the sum of the size of the largest necessary memory area and the size of the second largest necessary memory area as the continuous memory area CM. For example, the size of the continuous memory area CM allocated to allocate any two of USB moving image playback (40 MB), terrestrial digital playback (32 MB), and mirror link playback (16 MB) is 40 MB + 32 MB = 72 MB.

  The determination unit 33 determines whether the allocated memory area allocated to the process being executed is allocated from one end (minimum address) or the other end (maximum address) of the continuous memory area CM. A determination process is performed. The allocation unit 31 performs a memory allocation process based on the determination result of the determination unit 33. That is, the allocating unit 31 allocates an allocated memory area for a process to be executed next from one end or the other end of the continuous memory area CM to which the process being executed is not allocated.

  The memory 12 is a physical memory (also referred to as a real memory) such as a RAM (Random Access Memory), for example. In the moving image reproduction process by the hardware decoder 13 and other processes based on the control of the control unit 11, A memory area. The memory 12 is bidirectionally connected to the control unit 11 via the line L2, and bidirectionally connected to the hardware decoder 13 via the line L3.

  In the memory 12, as shown in FIG. 3, a memory area in which a plurality of unit memory areas UM are successively arranged side by side is secured as a continuous memory area CM. Then, an allocation memory area (first allocation memory area and second allocation memory area) is allocated to the continuous memory area CM by the allocation unit 31 of the continuous memory area management module 22 and decoded by the hardware decoder 13. The moving image data VD is developed.

  The hardware decoder 13 decodes the moving image data VD in response to the decoding request DR from the control unit 11, and expands the decoded data DD, which is a decoding result, into the allocated memory area in the continuous memory area CM. When performing two of USB video playback, terrestrial digital playback, and mirror link playback at the same time, the hardware decoder 13 decodes decoded data DD1 and second video data VD2 obtained by decoding the first video data VD1. The decoded data DD2 is expanded in the first allocation memory area and the second allocation memory area, respectively.

  The first display 14 and the second display 15 reproduce (display) moving images based on the decoded data DD decoded by the hardware decoder 13 and expanded in the continuous memory area CM in the memory 12. The 1st display 14 and the 2nd display 15 are each provided in the front part and rear part of moving bodies, such as a car, for example as an in-vehicle display.

  Next, a memory allocation process performed by the allocation unit 31 of the continuous memory area management module 22 will be described with reference to FIG. Here, for example, a case where a 72 MB continuous memory area CM is secured in the continuous memory area securing process will be described as an example.

  FIG. 4A schematically shows a 72 MB continuous memory area CM (that is, 8 × 9 = 72 MB) configured by continuously arranging nine unit memory areas UM with the unit memory area UM being 8 MB. FIG. In the figure, “Min” indicates the position of the minimum address in the continuous memory area CM, and “Max” indicates the position of the maximum address. That is, one end portion and the other end portion of the continuous memory area CM schematically shown correspond to the minimum address and the maximum address.

  In a state where neither the first display 14 nor the second display 15 is executing the moving image reproduction process, when starting the first moving image reproduction (hereinafter referred to as the first process) on one of the displays, the continuous memory The allocation unit 31 of the area management module 22 allocates an allocated memory area for the first process from the minimum address in the continuous memory area CM. For example, when the first process is mirror link reproduction on the first display 14, the size of the allocated memory area PA of the first process is 16 MB, which is a necessary memory area for mirror link reproduction. Accordingly, as shown in FIG. 4B, the allocation unit 31 sets an area of 16 MB from one end (that is, the minimum address) of the continuous memory area CM as the allocation memory area PA of the first process. assign.

  Next, when the next video playback (hereinafter referred to as second processing) is started on the second display 15 while the video playback (first processing) is being performed on the first display 14, the continuous memory area management module 22. The allocation unit 31 allocates an allocated memory area for the second process from the maximum address in the continuous memory area CM. For example, when the second process is terrestrial digital reproduction on the second display 15, the size of the allocated memory area P-B of the second process is 32 MB, which is a necessary memory area for terrestrial digital reproduction. Therefore, as shown in FIG. 4C, the allocation unit 31 allocates an area of 32 MB from the other end (maximum address) of the continuous memory area CM as an allocation memory area P-B for the second process.

  Thereafter, when the first process is finished, as shown in FIG. 4D, the allocated memory area PA of the first process is cleared, and an area including one end of the continuous memory area CM becomes a free area. .

  Next, when the next video playback (hereinafter referred to as the third processing) is started on the first display 14 while the video playback (second processing) is being performed on the second display 15, the continuous memory area management module 22 is started. The allocation unit 31 allocates an allocated memory area for the third process from the minimum address in the continuous memory area CM. For example, when the third process is USB moving image reproduction on the first display 14, the size of the allocated memory area PC in the third process is 40 MB, which is a necessary memory area for USB moving image reproduction. Therefore, as shown in FIG. 4E, the continuous memory area management module 22 assigns an area for 40 MB from one end (minimum address) of the continuous memory area CM to the allocated memory area PC in the third process. Assign as.

  As described above, when the moving image reproduction is performed in parallel on the first display 14 and the second display, the allocating unit 31 of the continuous memory area management module 22 assigns the memory area for one moving image reproduction process to the continuous memory area CM. Allocating from one end, the other memory area for moving image reproduction processing is allocated from the other end of the continuous memory area CM. Therefore, even when the first display 14 and the second display 15 repeatedly perform a plurality of types of moving image reproduction (moving image reproduction of a plurality of types of sources) having different necessary memory areas, fragmentation does not occur.

  Unlike this, for example, as shown in FIG. 5, in the continuous memory area CM (FIG. 5A), the allocated memory area PA of the first process (for example, 16 MB) is set to one end (minimum address). (FIG. 5 (b)), when the allocated memory area P-B (for example, 32 MB) of the second process is allocated to the subsequent area (FIG. 5 (c)), the first process is terminated after that. Empty areas occur at both ends of the memory area CM (FIG. 5D). Therefore, when a third process (for example, 40 MB) having a larger memory area than the first process is subsequently performed, a sufficient continuous memory area cannot be secured, and fragmentation occurs.

  In addition, when allocation is performed as shown in FIG. 5, in order to suppress the occurrence of fragmentation, a memory area for video playback so that a sufficient free area is generated even when different types of video playback are repeated. Must be secured in advance. However, in that case, a memory area for processing other than the moving image reproduction processing performed by the OS is compressed.

  On the other hand, according to the allocating device of this embodiment, the allocating unit 31 of the continuous memory area management module 22 uses the largest necessary memory area size and the second largest necessary memory area size in the continuous memory area securing process. Therefore, it is only necessary to secure a continuous memory area having the size of the sum as the continuous memory area CM, so that it is not necessary to secure an extra memory area assuming fragmentation.

  Further, in the allocation device of the present embodiment, the allocation unit 31 allocates the allocated memory area of the first process from one end (minimum address) of the continuous memory area CM, and performs the second process from the other end (maximum address). By allocating the allocated memory area, it is not necessary to perform a process such as once allocating the allocated memory area and then moving the allocated area, in order to prevent the free area from being distributed, which leads to fragmentation. Therefore, an increase in load associated with the movement process does not occur. That is, according to the allocation device of the present embodiment, it is possible to prevent the free area from being subdivided while suppressing an increase in processing load in the allocation of the continuous memory area.

  In the above-described embodiment, the case where the present invention is applied to the continuous memory area management module in the moving image reproduction system that separately reproduces moving images on the two displays has been described as an example. Absent. The present invention can be applied to all allocation devices that allocate continuous memory areas in physical memory for a plurality of processes. That is, according to the present invention, a first allocated memory area is allocated to one process from one end of the continuous memory area, and a second allocated memory area is allocated to another process during execution of the one process. Are allocated from the other end of the continuous memory area.

  In the above-described embodiment, the allocation unit 31 allocates the first allocation memory area to one of the three types of video playback processes, that is, USB video playback, terrestrial digital playback, and mirror link playback. An example in which the second allocated memory area is allocated to one of them has been described. However, the types of processing are not limited to these three types. The allocating unit 31 allocates the first allocated memory area from one end of the continuous memory area CM to one process among the plurality of processes, and performs the first allocation to other processes during the execution of the first process. It is sufficient if two allocated memory areas are allocated from the other end of the continuous memory area CM.

  The series of processing described in the above embodiments can be performed by computer processing according to a program stored in a recording medium such as a ROM.

DESCRIPTION OF SYMBOLS 10 Movie reproduction system 11 Control part 12 Memory 13 Hardware decoder 14 1st display 15 2nd display 21 Movie reproduction application module 22 Continuous memory area management module 31 Allocation part 32 Acquisition part 33 Determination part

Claims (9)

An allocation device for allocating a continuous memory area in which a plurality of unit memory areas in a physical memory are sequentially juxtaposed to a plurality of processes,
A first allocated memory area is allocated to one of the plurality of processes from one end of the continuous memory area, and a second allocated memory is allocated to another process during execution of the first process. An allocation apparatus comprising: an allocation unit that allocates an area from the other end of the continuous memory area. A determination unit that determines whether the allocated memory area allocated to the process being executed is allocated from one end or the other end of the continuous memory area;
The allocation unit is an allocation memory for processing to be executed other than the process being executed from one end of the continuous memory area or the other end to which the process being executed is not assigned. The allocation apparatus according to claim 1, wherein an allocation area is allocated. An acquisition unit that acquires memory information indicating a memory amount required for each of the plurality of processes;
The allocating unit allocates a memory area having a total memory amount of a memory amount of a process requiring the largest memory amount and a memory amount of a second largest process among the plurality of processes based on the memory information. 3. The allocation device according to claim 1, wherein the allocation device is set as a continuous memory area.   The allocation apparatus according to claim 1, wherein the plurality of processes are hardware processes. A memory area allocation method in an allocation apparatus for allocating a continuous memory area in which a plurality of unit memory areas in a physical memory are sequentially juxtaposed to a plurality of processes,
Allocating a first allocated memory area to one of the plurality of processes from one end of the continuous memory area;
An allocation method comprising: causing the allocation unit to allocate a second allocated memory area to another process from the other end of the continuous memory area during execution of the first process. . Causing the determination means to determine whether the allocated memory area allocated to the process being executed is allocated from one end or the other end of the continuous memory area;
An allocation memory for processing to be executed other than the processing being executed from one end of the continuous memory area to which the processing being executed is not assigned to the allocation means. An allocation method according to claim 5, further comprising a step of allocating an area. Obtaining the memory information indicating the amount of memory necessary for each of the plurality of processes;
Based on the memory information, the allocating unit includes a memory area having a total memory amount of a memory amount of a process requiring the largest memory amount and a memory amount of a second largest process among the plurality of processes. The allocation method according to claim 5, further comprising a step of setting as a continuous memory area. A program for allocating a continuous memory area in which a plurality of unit memory areas in a physical memory are sequentially juxtaposed to a plurality of processes,
Allocating a first allocated memory area to one of the plurality of processes from one end of the continuous memory area;
Allocating a second allocated memory area to another process from the other end of the continuous memory area during execution of the first process. A recording medium for recording a program for allocating a continuous memory area in which a plurality of unit memory areas in a physical memory are sequentially juxtaposed to a plurality of processes, the program being stored in a computer,
Allocating a first allocated memory area to one of the plurality of processes from one end of the continuous memory area;
A step of allocating a second allocated memory area to another process from the other end of the continuous memory area during execution of the first process.

Images