JP2011034510A - Memory allocation device and memory allocation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure a buffer to be used for processing as a consecutive area on a memory. <P>SOLUTION: The memory allocation device includes a buffer allocation information output module 511, a buffer memory range determination module 522, and a processing module 524. One or more processes which require a buffer consecutive area on the memory are represented by a group of process names, a combination of processes not executed in parallel among the processes is represented by an exclusive relation, and one or more memory range candidates available for the processes as the buffer are represented by buffer allocation information BAI. The module 511 outputs the BAI for each process based on the exclusive relation or the like. The module 522 selects, when a specific process contained in the group of process names is started, a memory range which does not overlap a memory range used by the other process at the time when the specific process is started, in the memory range candidates described in the BAI. The module 524 secures the selected memory range on the memory as the buffer, and executes the specific process by use of the secured buffer. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a memory allocation method for securing a buffer used by a process in a data stream recording / playback process or the like as a continuous area on a memory, and a memory allocation apparatus using this method.

  In recent years, large-capacity hard disk drives (HDDs) have been supplied at low cost, and hundreds of gigabytes or terabytes of HDDs are equipped in personal computers (PCs), digital TVs, digital video recorders, and the like. . Such a large-capacity HDD is frequently used for recording and reproducing data streams including moving image information.

  In a large-capacity storage medium represented by an HDD, a relatively large-capacity high-speed memory (buffer) is used to smoothly perform recording and reproduction processing of a data stream having a large amount of information such as high-definition digital TV broadcasting. Various proposals have been made for controlling this type of memory (buffer). For example, when recording / playback processing of a digital TV broadcast stream is executed in a PC (AV personal computer) or a digital video recorder (HDD recorder), if a memory is required to execute the processing, a memory area is dynamically secured and used. A mechanism has been proposed (see Patent Document 1).

JP 2001-325145 A

  In the data storage system of Patent Document 1 and the data broadcast receiving apparatus using the data storage system, the data area of the RAM 142 includes a partition area to which a buffer area is allocated according to an allocation request and a region area to which a segment area is allocated according to the allocation request. . The buffer area corresponds to predetermined fixed length data, and the segment area corresponds to the data length to be stored. The arithmetic processing unit 144 determines whether to store data in the partition area or the region area according to the data length of the digital data, and generates an allocation request.

  The dynamic buffer securing method of Patent Document 1 is effective when the process to be executed and the buffer size required for the process cannot be determined statically. However, in order to smoothly perform recording / playback processing of a data stream having a large amount of information such as digital TV broadcasting, it is necessary to prepare a sufficiently large memory area, and a continuous area is used as a buffer for the processing. There is no guarantee that it can be secured at any time.

  When a continuous area on the memory cannot be secured for the processing buffer, the area used as the processing buffer is distributed and fragmented on the memory. If an area used as a buffer is fragmented, an overhead occurs in the execution of processing. In addition, when a continuous area on the memory cannot be secured for the processing buffer, there may be a halfway unused memory area between the memory areas used as buffers. Such an empty memory area is wasted.

  One of the problems of the present invention is to make it possible to secure a buffer used by processing as a continuous area on a memory.

  The memory allocation device according to an embodiment of the present invention includes a buffer allocation information output module (511), a buffer memory range determination module (522), and a processing module (524). Now, one or more processes that need to secure a continuous area to be used as a buffer on the memory (530) are represented by "a set of process names", and the size of the buffer used by these processes is represented by "buffer size information". A combination of processes that are not executed in parallel between these processes is represented by “exclusive relationship”, and one or more memory range candidates that can be used as buffers by the process are represented by “buffer allocation information”. In this case, the buffer allocation information output module (511) outputs buffer allocation information (BAI) for each process based on the set of process names, the buffer size information, and the exclusive relationship. Further, when starting a specific process included in the set of process names, the buffer memory range determination module (522) selects the specific process from among the memory range candidates described in the buffer allocation information (BAI). A memory range (continuous area on the memory) that does not overlap with the memory range used for other processing at the time of starting is selected. The processing module (524) secures the selected memory range as a buffer in the memory (530), and executes a specific process using the secured buffer.

  According to the present invention, the buffer used by the process can be secured as a continuous area on the memory.

The figure explaining the structure of the memory allocation apparatus which concerns on one embodiment of this invention. The figure explaining the structure of the memory allocation apparatus which concerns on other embodiment of this invention. The figure explaining the structure of the memory area which can be used as a buffer. The figure explaining buffer allocation information. The figure explaining the case where the useless area | region which cannot be used in the memory area which can be used as a buffer arises. The flowchart figure explaining an example of the process which allocates a buffer to a memory area. The figure explaining an example of the initial state of buffer allocation information. The figure explaining an example when 2 parallel processing can be performed using a buffer (after pruning). The figure explaining an example when 3 parallel processing cannot be performed using a buffer (before pruning). The figure explaining an example when 3 parallel processing can be performed using a buffer (after pruning). The figure explaining an example of the depth priority search in a buffer allocation process. The figure explaining the buffer allocation information initial state before the search range of buffer allocation is narrowed down. The flowchart figure explaining an example of the process in the partial problem preparation part of FIG. The figure explaining the application example of the memory allocation apparatus of FIG. 1 or FIG. The figure explaining an example of a structure of the digital video recorder provided with the memory allocation apparatus of FIG. 1 or FIG.

  Hereinafter, various embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram for explaining the configuration of a memory allocation device according to an embodiment of the present invention. The memory allocation device 500 determines how to allocate a buffer continuous area to the memory 530, and includes a buffer allocation information output device (buffer allocation information output module) 511 and a data storage unit (storage module) 520. , A buffer memory range determination unit (buffer memory range determination module) 522, and a processing execution unit (processing module) 524.

  FIG. 2 is a diagram for explaining the configuration of a memory allocation device according to another embodiment of the present invention. The configuration of FIG. 2 is the same as the configuration of FIG. 1 except that a partial problem creation unit (partial problem creation module) 505 is added to the buffer allocation information output device 511. The processing function of the partial problem creation unit 505 will be described later with reference to FIG. In the following, the configuration common to FIGS. 1 and 2 will be described first.

  In the configuration of FIG. 1, the memory 530 is a read / write memory that can be used for processing a plurality of high-definition video signal streams, for example, and is composed of SRAM or DRAM having the capacity and speed necessary for the processing. In the memory 530, a memory area (buffer area) 532 that can be used as a buffer for stream processing or the like can be appropriately secured.

  FIG. 3 is a diagram illustrating the configuration of the memory area 532 that can be used as a buffer. As illustrated in FIG. 3, the memory area (buffer area) 532 is divided (or separated) into a static buffer area 534 and a dynamic buffer area 536, and each is managed individually. Here, the static buffer area 534 is a buffer area allocated to a process whose buffer size to be used is known. The area 532 other than the static buffer area 534 becomes the dynamic buffer area 536.

  The embodiment of the present invention is characterized by the usage of the static buffer area 534. The dynamic buffer area 536 is used in a process that does not use the static buffer area 534 or a process that cannot be covered by the static buffer area 534. A method for using the dynamic buffer area 536 may be a known method. Specifically, the dynamic buffer area 536 can be used, for example, in the same manner as the segment area in Patent Document 1 (Japanese Patent Laid-Open No. 2001-325145) described above.

It should be noted that another existing method can be used for “dynamic memory allocation” for the dynamic buffer area 536. The existing method for “dynamic memory allocation” is used in the malloc function in the C language. For this, see:
B. W. Carnihan, D.C. M.M. Richie, “Programming Language C”, Kyoritsu Shuppan, 1989
In the configuration of FIG. 1, the process execution unit 524 is configured by, for example, a device-embedded computer (a CPU or MPU that executes predetermined firmware). For example, when executing a certain stream process A, the process execution unit 524 secures the memory range selected by the buffer memory range determination unit 522 on the memory 530 as a buffer used by the process A, and executes the process A. .

  When the process execution unit 524 starts the process A, the buffer memory range determination unit 522 selects one memory range from the buffer allocation information BAI stored in the data storage unit 520. One of them is a memory range candidate that can be used as a buffer by the process A and that does not overlap with a memory range currently used by another stream process. One of the selected memory ranges is used as a buffer for process A.

  Here, when there are two or more processes to be executed, the buffer memory range determination unit 522 can use any process in any order as long as the processes are not in an exclusive relationship. The buffer range is always ensured (this point will be described in detail later).

The buffer allocation information BAI stored in the data storage unit 520 includes one or more memory range candidates that can be used as a buffer memory for each of one or more stream processes that may be executed. (The buffer allocation information BAI will be described later with reference to FIG. 4 and the like.)
In the configuration of FIG. 1, the buffer allocation information output device 511 includes a processing information input unit (processing information input module) 501, an inter-process exclusive relationship input unit (inter-process exclusive relationship input module) 502, and an input information storage unit 503. , A target memory size determination unit (target memory size determination module) 504, a buffer allocation determination unit 509, and a buffer allocation information output unit 510. Here, the buffer allocation determination unit 509 includes an executable / impossible determination unit (executable / impossible determination module) 506, a buffer allocation search unit (buffer allocation search module) 507, and a search range narrowing unit (search range narrowing). Module) 508.

  From the process information input unit 501, the process name and the buffer size used by the process are input for all processes that may be executed.

A combination of processes that are not executed in parallel is input from the inter-process exclusion relation input unit 502. (Conversely, there is also a method of inputting a combination of stream processes to be executed in parallel from the inter-process exclusive relationship input unit 502. If a combination of processes to be executed in parallel is known, a combination of other existing processes is executed in parallel. Can be treated as a combination of processing not done)
The input information storage unit 503 stores information input from the processing information input unit 501 and the inter-process exclusion relationship input unit 502.

  The target memory size determination unit 504 of the buffer allocation information output device 511 first assumes that the size (target value) of the memory used as the static buffer area 534 (see FIG. 3) is a sufficiently small value and can use the available buffer. The allocation information is searched (the search method will be described later). If an executable buffer memory allocation cannot be found with the target memory size (in other words, the target memory size can be used regardless of the order in which processing occurs as long as it is a combination of processes that are not in an exclusive relationship. If the buffer range cannot be guaranteed ”, the target memory size is updated (increased), and the process of searching for executable buffer allocation information is repeated. The target memory size determination unit 504 sets the target value of the memory size and updates it appropriately.

  Here, if the difference between the minimum memory size that can be processed using the static buffer area 534 and the initially set target memory size is large, it takes a lot of calculation time to calculate the buffer memory allocation. Therefore, the target memory size with the smallest possible difference is set first.

  The executable / impossible determination unit 506 determines whether all processing combinations that are not in the exclusive relationship with the current buffer allocation information BAI can be executed (exclusive relationship will be described later).

  The buffer allocation search unit 507 searches for a memory allocation that can be processed within the target memory size set by the target memory size determination unit 504.

  The search range narrowing unit 508 narrows down the range that the buffer allocation search unit 507 searches. The search range narrowing unit 508 is used to calculate buffer allocation information BAI that can be efficiently executed using input information from the input units 501 and 502 and the like.

  The buffer allocation information output unit 510 outputs buffer allocation information BAI that can be processed and that minimizes the size of memory used as a buffer (static buffer area 534) (the specific method will be described later). .

  FIG. 4 is a diagram for explaining the contents of the buffer allocation information BAI output from the buffer allocation information output unit 510 and stored in the data storage unit 520. The buffer allocation information BAI (information for buffer memory allocation) stored in the data storage unit 520 of FIG. 1 or FIG. 2 is as illustrated in FIG. FIG. 4 exemplifies the range candidates usable as the buffer memory (static buffer area 534) for the seven processes A to G. However, the buffer memory size (unit is arbitrary) required to execute each of the processes A to G is 2 units for process A, 5 units for process B, 3 units for process C, 7 units for process D, It is assumed that E is 4 units, process F is 7 units, and process G is 15 units. Here, for example, if one unit is 1 MB (megabytes), the n unit is nMB.

In the illustration of FIG.
The buffer memory range that can be used by process A is only addresses 29 to 30 in the memory 530;
The buffer memory range that can be used by the process B is only the addresses 29 to 33 of the memory 530;
The buffer memory range that can be used by process C is 0 to 2 or 15 to 17 in the memory 530;
The buffer memory range that can be used by the process D is 0 to 6 addresses or 15 to 21 addresses in the memory 530;
The buffer memory range that can be used by the process E is only 22 to 25 in the memory 530;
The buffer memory range that can be used by the process F is only 22 to 28 in the memory 530;
The buffer memory range that can be used by the process G is shown as 0 address 14 or 7 address to 21 address in the memory 530. In the case of such buffer memory allocation, the buffer memory size necessary for execution of processing (the size of the static buffer area 534) is 34 units (for example, 34 MB) from address 0 to address 33. Such information is created as buffer allocation information BAI for the processes A to G and stored in the data storage unit 520.

  FIG. 5 is a diagram for explaining a case where a useless area that cannot be used occurs in a memory area that can be used as a buffer. If the memory allocation device 500 of FIG. 1 or FIG. 2 is not used, there is a possibility that a useless area that cannot be used as a buffer may be generated in the memory area (buffer area) 532 as illustrated in FIG. In the apparatus 500 of FIG. 1 or FIG. 2, the generation of such a useless area is prevented by the operation described below.

  Assume that a set of process names to be executed in a device such as a PC or HDD recorder having a configuration corresponding to the memory allocation device 500 is {A, B, C, D,. These process names indicate processes that are known to be frequently executed, have a known buffer size necessary for execution, and want to secure a continuous memory area as a buffer. Here, it is assumed that the buffer size required for execution of each process is given by s (N) (N is the process name).

  For example, three processes A (s (A) = 3), B (s (B) = 5), and C (s (C) = 1) are “A start → B start → A end (buffer release) → Consider the case where the processes are executed in the order of “C start →. In that case, if a method of simply allocating and securing necessary continuous areas at the location where the buffer is open is used, a useless memory area that cannot be used as shown in FIG. 5 is required. Although it is conceivable to refill the buffer area, this requires extra processing time. Therefore, in this example, if the process A always uses the addresses 0 to 2 of the memory, the process B uses the addresses 3 to 7 of the memory, and the process C always uses the address 8 of the memory, it is a useless memory area. Will not occur.

  However, in the apparatus 500 of FIG. 1 or FIG. 2, it is possible not only to prevent the generation of a useless memory area but also to further reduce the necessary memory amount. That is, for example, when it is known in advance that “Process A and Process B are not executed simultaneously”, the memory area used as a buffer by Process A and the memory area used as a buffer by Process B are shared, and the necessary memory Try to reduce. For this purpose, the memory allocation device 500 shown in FIG. 1 or FIG. 2 provides information (how to allocate a memory area used as a buffer for processing to reduce the necessary memory to a minimum) (buffer allocation). Information BAI) is output.

  A set of process names that are known to be executed and whose buffer size necessary for execution is known and for which a continuous memory area is to be secured as a buffer are represented by {A, B, C, D, E, F, G} and the buffer size required for processing is s (A) = 2, s (B) = 5, s (C) = 3, s (D) = 3, s (E) = 4, s (F) = 7 and s (G) = 15. Furthermore, the four processes are not executed simultaneously, and the combinations of processes A and B, processes E and F, processes C and D and G, processes E and G and C, and processes E and G and D are executed simultaneously. Consider the case where it is known in advance that this will not be done. Among these pieces of known information, information on a set of processing names and information on a buffer size required for processing are input from the processing information input unit 501. In addition, information of combinations of processes that are not executed simultaneously among the known information is input from the inter-process exclusive relation input unit 502.

  When the above-described known information is input to the processing information input unit 501 and the inter-process exclusion relationship input unit 502, the buffer allocation information output unit 510 outputs the buffer allocation information BAI having the contents illustrated in FIG. From this buffer allocation information BAI, the memory allocation device 500 allocates a memory area from addresses 0 to 33 to a static memory area 534 for buffers necessary for executing processes A to G (memory dedicated to processes A to G). Area). For processes other than the processes A to G, the dynamic memory area 536 (see FIG. 3) is used, and a buffer is secured by an existing method (such as the “method used in the malloc function in C language” described above). .

  FIG. 6 is a flowchart for explaining an example of processing in which the memory allocation device 500 allocates a buffer to the static memory area 534 in the memory 530. The memory allocation device 500 calculates a combination of parallel processes that may be executed from the exclusive relationship input from the inter-process exclusive relationship input unit 502, and stores the calculated parallel processing combination in the input information storage unit 503. Store (ST1). Here, the exclusive relationship input from the inter-process exclusive relationship input unit 502 refers to a relationship of a plurality of processes that are not executed in parallel.

  Among the combinations of parallel processes stored in the input information storage unit 503, the target memory size determination unit 504 detects the combination that maximizes the sum of the buffer sizes required for each process (ST2). The sum (maximum value) of the detected necessary buffer sizes becomes the initial value of the target memory size for the static buffer area 534.

  In the case of reaching ST2 in the order of “... → ST8 → ST2” in the process of FIG. 6, the target memory size is increased by the minimum unit from the current state (initial value at first) in the process of ST2. Update. When the static buffer area 534 is increased or decreased with a granularity of MB (megabyte) unit, the minimum unit here is 1 MB.

  Subsequently, the buffer allocation search unit 507 in the buffer allocation determination unit 509 initializes the buffer allocation information BAI (ST3). In this initialization, all the memory range candidates that each process may reserve as a buffer are listed. For example, assuming that the target memory size is 11 units (11 MB if 1 unit is 1 MB) and processing A (required buffer size 7 units) and processing B (required buffer size 4 units) that do not have an exclusive relationship are input, The contents of the buffer allocation information BAI at the time of conversion (candidate memory ranges that each process may secure as a buffer) are as shown in FIG. 7 (the illustration of FIG. 7 shows the buffer size along the horizontal axis direction) Each unit is vertically divided).

  When the buffer allocation information BAI is initialized, the search range narrowing unit 508 in the buffer allocation determination unit 509 prunes the buffer allocation information BAI (ST4). Here, pruning refers to deleting a memory range candidate for which parallel processing is impossible from among a plurality of memory range candidates.

  For example, consider a case where process A and process B operate in parallel in the initial state of FIG. If the process A uses the memory range candidate A2, the process B cannot use any of the memory range candidates (B1 to B8) and cannot operate in parallel, so the memory range candidate A2 is deleted (pruned) from the candidates. Similarly, when candidates are deleted, buffer allocation information BAI pruned as shown in FIG. 8 is obtained (in FIG. 8, memory range candidates deleted by pruning are indicated by x). In this example, pruning is performed in consideration of two parallel operations. As a result of this pruning, memory range candidates A1 and A5 remain for process A, and memory range candidates B1 and B8 remain for process B.

  As a more complicated example, pruning considering three parallel operations will be described. Consider a case where there is buffer allocation information (initial state) as shown in FIG. 9, and processing A, processing B, and processing C operate in parallel. If the process A uses the memory range candidate A2, no parallel operation can be performed regardless of how the process B and the process C select the memory range candidate. Therefore, the memory range candidate A2 is deleted from the candidate (pruning). To do. Similarly, when candidates are deleted, buffer allocation information BAI pruned as shown in FIG. 10 is obtained. Pruning considering multi-parallel operations such as 4-parallel operation, 5-parallel operation,.

  Returning to the description of the processing in FIG. When the pruning of the buffer allocation information is completed, the buffer allocation search unit 507 presupposes a memory range candidate to be used as a buffer for each process (ST5). In this setting, the buffer allocation search unit 507 determines the order of processing assuming a memory range candidate to be used (the number of memory range candidates assumed here is one or more).

  Subsequently, the buffer allocation search unit 507 determines whether or not the memory range candidate has been assumed for all the processes (ST6). If the assumption of the memory range candidate is not performed for all the processes (NO in ST6), the pruning of buffer allocation information (ST4) and the assumption setting of the memory range candidate used as a buffer (ST5) are performed again.

  When the assumption of the memory range candidate is completed for all the processes (YES in ST6), the executable / impossible determination unit 506 in the buffer allocation determination unit 509 reads “The assumed memory range candidate as the buffer allocation information. If selected, if it is a processing combination that does not have an exclusive relationship, it is determined whether or not the memory range to be used as a buffer can be selected regardless of the order in which the processing is started. For example, if process A, process B, and process C operate in parallel, the execution start order is “A → B → C”, “A → C → B”, “B → A → C”, “B → C”. In any of the six patterns of “→ A”, “C → A → B”, and “C → B → A”, it is determined whether or not the memory range to be used as a buffer by the process can be selected (ST7). If the memory range that the process uses as a buffer can be selected, the process can be executed. If not, the process is not executable.

  If it is determined that execution is not possible (NO in ST7), it is checked whether the buffer allocation search unit 507 has completed the assumption setting for all patterns of all processing (ST8). If the assumption setting has not been completed for all patterns of all processes (NO in ST8), the processes of ST4 to ST7 are executed again.

  When the assumption setting has been completed for all patterns of all processes (YES in ST8), there is no executable buffer allocation information with the current target memory size. In this case, the process returns to ST2, and after updating the target memory size, the search for executable buffer allocation information (the processes of ST3 to ST7) is performed again.

  If it is determined in ST7 that execution is possible (YES in ST7), the currently assumed memory range candidate (for example, a memory range other than x in FIG. 8 or 10 becomes a candidate) is used as buffer allocation information. Is output from the buffer allocation information output unit 510 as final buffer allocation information BAI (ST9). The output buffer allocation information BAI is stored in the data storage unit 520 (ST10).

  The buffer allocation information BAI output in ST9 has such a content that the buffer memory range determination unit 522 can always select a buffer necessary for executing processing (determined in ST7). Further, the target memory size determination unit 504 has a mechanism for gradually increasing the target memory size in a minimum unit (for example, 1 MB) from a value equal to or less than the minimum optimum memory size (update in ST2). ). For this reason, the buffer allocation information BAI output in ST9 is the content that minimizes the size of the static buffer area 534 within a range where processing can be executed.

  Thus, the memory range to be used as the static buffer area 534 can be determined from the buffer allocation information BAI output in ST9. The memory allocation device 500 uses an area (dynamic buffer area 536) that is not used as the static buffer area 534 when executing a process that has not been input from the process information input unit 501. On the other hand, with respect to the processing input from the processing information input unit 501, the buffer allocation information BAI is used to secure a memory range that is not being used by a currently executing process as a buffer (it is guaranteed that it can be ensured). To execute the process.

  That is, a memory range that does not overlap between processes is selected from the buffer allocation information BAI stored in the data storage unit 520 (ST11) (A1, A5, and B1 in the case of two parallel operations in FIG. 8 as an example) B8 is selected as a non-overlapping memory range between process A and process B). The buffer memory range determination unit 522 secures the selected memory range on the memory 530 for buffer use (ST12). The process execution unit 524 executes one or more processes using the buffer memory range thus secured (ST13).

  In the case where there is one or more memory range candidates assumed by the buffer allocation search unit 507, ST5 is the same in ST5 except that ST5 is reached in the order of “... → ST8 → ST2 → ST3 → ST4 → ST5”. A combination of memory range candidates once assumed for processing is never assumed again. However, when arriving at ST5 in the order of “... → ST8 → ST2 → ST3 → ST4 → ST5”, information related to combinations of hypothetical processing and hypothetical memory range candidates up to now is cleared. An assumption is made from the processing process (the assumption setting of ST5 is performed).

  When reaching ST5 in the order of "ST1-> ST2-> ST3-> ST4-> ST5" or "...-> ST6-> ST4-> ST5", the memory range candidate to be used is determined for the next process that has not yet been assumed in ST5. Make assumptions. Further, when the process reaches ST5 in the order of “... → ST8 → ST4 → ST5”, the following assumption is made for the last assumed process. However, if the last assumption process has already been made for all patterns, the process returns to the previous process and makes the following assumption. In the previous process, if all the patterns have already been assumed, the previous state is further restored (if all assumptions have been set for all processes, “... → ST8 ST5 is not reached in the order of “ST4 → ST5”). The operation leading to ST5 in this way corresponds to a so-called “depth-first search”.

  FIG. 11 is a diagram for explaining an example of “depth-first search” in the buffer allocation process using a graphical image. For example, in the case where memory range candidates as illustrated in FIG. 10 can be assumed for three processes (processes A, B, and C), let us assume the assumption of memory range candidates for process B (FIG. 6). ST5). When searching a plurality of process B candidate memory areas in the horizontal direction (width direction), a so-called “width priority search” is performed. On the other hand, in the “depth-first search”, a memory range candidate for process A is assumed for one of the plurality of process B memory range candidates (ST5). At that time, with respect to the memory range candidate of the process A that cannot be executed simultaneously with the process B, the depth-first search thereafter is terminated (this can reduce the processing time). When one or more memory range candidates of process A that can be executed simultaneously with process B are found, a memory range candidate for process C is assumed for one of them (ST5). At that time, if a memory range candidate of process C that can be executed simultaneously with process B and process A is found, a solution (a combination of memory range candidates) that can execute three processes A, B, and C in parallel is found. Therefore, the depth-first search algorithm ends there.

  In the embodiment of the present invention, in order to output the buffer allocation information BAI at high speed, in addition to setting the target memory size to an initial value (ST2 in FIG. 6), as a device for narrowing the search range of the buffer allocation search unit 507, “Depth-first search” is performed. The search method includes “width-first search”, but in the embodiment of the present invention, “depth-first search” has been described.

For the above-mentioned “depth-first search” and “width-first search”, see:
Ishihata Kiyoshi, Iwanami Lecture Software Science 3 “Algorithms and Data Structures”, Iwanami Shoten, 1989
FIG. 12 is a diagram illustrating an initial state of buffer allocation information before the search range of buffer allocation is narrowed down. The search range of the buffer allocation search unit 507 is narrowed down by the search range narrowing unit 508 (pruning in ST4 of FIG. 6). At that time, it is possible to further narrow down by introducing the following concept. For example, when there is a process A (s (A) = 7), a process B (s (B) = 6), and a process C (s (C) = 1), and the target memory size is 7 units, the buffer allocation information The initial state is as shown in FIG. However, in searching for a solution (a combination of memory range candidates), the conditions for the memory range candidates C2 to C6 in FIG. 12 are the same (the overlapping relationship with the memory range candidates for other processes is the same). It is not necessary to set all of them as candidates, and any one is sufficient (this can be narrowed down).

  Even when the buffer allocation information that has already been created is updated, new buffer allocation information is created according to the above flow. When a process that uses the static buffer area 534 is newly added, the contents of the input information storage unit 503 are updated by adding the buffer size to be used for the process and the exclusive relationship related to the process, and the contents. Create new buffer allocation information based on. On the other hand, when reducing the processing using the static buffer area 534, information related to the processing to be deleted is deleted from the information stored in the input information storage unit 503, and a new buffer is allocated based on the content. Create information.

  By the way, in the processing of FIG. 6 executed by the memory allocation device 500 of FIG. 1 or FIG. 2, the initial value of the target memory size in ST2 is “executable buffer allocation information is required if the processing combination is not in an exclusive relationship”. The value is equal to or smaller than the “minimum memory size (optimum memory size)”. Here, even if the initial value of the target memory size is 0, the buffer allocation information can be obtained. However, if the optimal memory size and the initial value of the target memory size are too far apart, a solution (memory range) that allows parallel execution of processing is possible. It takes time to search for (candidate combinations) (it takes time because the number of iterations of the processing loop of ST2 to ST8 in FIG. 6 increases). Therefore, in the description of FIG. 6, for example, if the process A, the process B, and the process C operate in parallel, it is necessary that a memory size of at least s (A) + s (B) + s (C) is required. It is used when setting the initial size (ST2).

  Further, in the memory allocation device 500 of FIG. 2, in order to bring the optimum memory size and the initial value of the target memory size close to each other, a partial problem is created in the partial problem creation unit 505, and the memory size required for the partial problem is set as the target memory size. Introduces a mechanism to set the initial value of. Specifically, for example, when six or more processes are input to the process information input unit 501, five processes are selected in descending order of the buffer size required for executing the process (or in the order of increasing exclusive relationship). Then, the buffer allocation information when the five processes are assumed to be input is calculated. At this time, the buffer allocation information for the original input is calculated with the required size of the static buffer area as the initial value of the target memory size (ST2 in FIG. 6).

  FIG. 13 is a flowchart for explaining an example of processing in the partial problem creating unit 505 in FIG. First, it is checked whether or not the type of processing handled by the partial problem creation unit 505 is n + 1 or more (ST20). Here, for example, it is assumed that six or more processes (original problems) are input to the process information input unit 501 and n is 5. In this case, n + 1 becomes 6 (YES in ST20), and n (five) processes are selected in the order of increasing required buffer size or in the order of increasing exclusive relation (ST21). Then, a problem that leaves only the selected n processes and the exclusive relationship between the selected n processes is created as a partial problem (ST22), and the process of FIG. 6 is performed.

  Here, the reason why the partial problem is created in ST22 is that the target memory size (initial value) of the original problem is finally obtained "the memory size required (minimum required) by the buffer allocation information for request matching" It is because it is close to. Specifically, the “request match buffer allocation information” for the partial problem created by the partial problem creation unit 505 is calculated, and the memory size necessary for the “request match buffer allocation information” is calculated as the target memory size in the original problem. The initial value of.

  Thus, “the necessary memory size of the request matching buffer allocation information of the partial problem is set to the initial value of the target memory size of the original problem” is a feature of the configuration of FIG. 2 having the partial problem creation unit 505. .

  When the type of processing handled by the subproblem creation unit 505 is not n + 1 or more, that is, when the type is n or less (NO in ST20), the subproblem is not created (ST23), and the process of FIG. 6 is performed.

  In ST21, selecting “n in order of increasing required buffer size or in decreasing order of exclusion” selects the memory size required for the partial problem (buffer size that can handle n processes) as the original problem. This is to approach the optimum memory size (buffer size that can handle n + 1 processes).

  Further, when the number of types of processing of the original problem is quite large (when n + 1 in ST20 is very large), for example, the initial value of the target size of a certain partial problem 1 is determined from the partial problem 2 created from the partial problem 1. (In this example, the number of processes handled by subproblem 1> the number of processes handled by subproblem 2). That is, the partial problem can be created in multiple stages.

  FIG. 14 is a diagram illustrating an application example of the memory allocation device of FIG. 1 or FIG. Here, as a specific example of parallel processing using a buffer, processing of a plurality of digital broadcast streams will be described as an example. In the example of FIG. 14, as one of TV broadcast services, electronic program guide information (EPG information) sent from a broadcasting station, electronic program guide information distributed over the Internet (iEPG information), and a user input by remote control operation or the like. A processing information source 601 such as program reservation information is connected to the host 600. The host 600 is also connected to a display unit 604 that displays video.

  As the host 600, a PC (AV personal computer with a TV tuner), a digital TV, a video recorder with an HDD, or the like can be used. The host 600 is equipped with the memory allocation device 500 shown in FIG. 1 or 2 and the read / write memory 530 used as a buffer. The processing information source 601 corresponds to the processing information input unit 501 and the inter-process exclusion relationship input unit 502 of FIG. 1 or FIG. Information obtained from the processing information source 601 is stored in a storage area (not shown) corresponding to the input information storage unit 503 in FIG. 1 or FIG.

  The memory allocation device 500 handles a plurality of digital broadcast streams output from the host 600 as a plurality of processes (the plurality of processes are a video stream, an audio stream, and other data included in one broadcast program). It may be processing for a stream or the like). Then, buffer allocation information BAI is created based on these multiple processing exclusive relationships, and memory ranges are allocated to static buffer areas on the memory 530 based on the created BAI (FIGS. 8 and 10). Etc.).

  Through the processing described with reference to FIG. 6 and the like, a plurality of streams output from the host 600 are stored in a data storage such as an HDD via the memory 530 that can be buffered with the minimum necessary static buffer area size. Recorded by apparatus 100a. Alternatively, the plurality of streams read from the data storage device 100 a are returned to the host 600 via the memory 530. For example, the host 600 displays the video included in the read stream on the display unit 604 and reproduces the audio included in the read stream using a speaker (not shown).

  The apparatus of FIG. 14 further includes a USB interface (I / F) 110 and a network interface (I / F) 110a. One or more data streams buffered in the memory 530 are transferred to the one or more external data storage devices 100b to 100d via the USB I / F 110 and the USB hub 112. Alternatively, one or more data streams read from the external data storage devices 100 b to 100 d are returned to the host 600 via the memory 530 through the USB hub 112 and the USB I / F 110.

  Similarly, one or more data streams buffered in the memory 530 are transferred to the external data storage device 100e via the network I / F 110a. Alternatively, one or more data streams read from the external data storage device 100e are returned to the host 600 via the network I / F 110a and the memory 530.

  Here, as the network I / F 110a, an I / F conforming to IEEE 802.3 or DLNA (Digital Living Network Alliance) can be used.

  In the configuration of FIG. 14, when viewed from the external devices (100b to 100e), the memory allocation device 500 exists outside the device. Nevertheless, if the I / F that mediates data transfer corresponds to the required speed, the memory 530 is used as a buffer in the external device (100b to 100e) as in the case of using the data storage device 100a built in the device. Can be processed.

  In general, when processing to be executed is different for each user, such as processing in a PC, it is convenient to perform memory allocation by incorporating a memory allocation device 500 having a buffer allocation information output device 510. On the other hand, in the case of a device for which processing to be executed is fixed, such as an HDD video recorder, or a device that does not require frequent updating of buffer allocation information, it exists outside the device (external HDD recorder, etc.) It is more convenient to input the buffer allocation information BAI output from the buffer allocation information output device 510 to be input to the buffer memory range determination unit 522 and use it.

FIG. 15 is a diagram for explaining an example of the configuration of a digital video recorder including the memory allocation device of FIG. 1 or FIG. This video recorder has a plurality of TV tuners (82, 89), and is capable of simultaneously recording a plurality of TV broadcast programs (such as W recording). This video recorder has the memory allocation device 500 shown in FIG. 1 or FIG. 2, and the device 500 appropriately secures a static buffer area in the temporary storage unit 530. If the processing capacity of the main MPU 80 is sufficient, the processing of the memory allocation device 500 (the processing of FIG. 6 and the like) may be performed by the firmware of the MPU 80 <Summary of Embodiment>
The present invention is implemented when it is necessary to secure a continuous memory area as a buffer because high-speed processing execution is essential as in stream processing. At that time, the memory area that was originally available as a buffer is separated into the memory area that is used as a buffer by a known process (static buffer area) and the memory area that is used as a buffer by other processes (dynamic buffer area). To do. The buffer area for each process that uses the static buffer area is secured according to buffer allocation information BAI that represents a memory range in which each process can be used as a buffer. An existing method can be used as a method of using the dynamic buffer area. That is, the conventional process execution can be performed similarly.

  The buffer allocation information BAI is information representing a candidate (one or more) of a memory range that can be used as a buffer for each process that uses a static buffer area. With respect to processing using the static buffer area, the memory allocation device selects one memory range from candidates that does not overlap with the already used memory range, and allocates the memory range as a buffer. The processing execution device starts processing using the buffer. The buffer allocation information BAI is obtained from the buffer allocation information output unit 510 having the following features.

  The buffer allocation output unit 510 uses, as inputs, a process that uses a static buffer area, a buffer size that each process uses, and an exclusive relationship between these processes. As long as the processing combination is not in the exclusive relationship, the memory range used as a buffer by the processing can always be selected (processing can be executed), and the size of the static buffer area, regardless of the processing order The buffer allocation information BAI is output so that is minimized.

<Effect of Embodiment>
When new processing that uses the static buffer area occurs or when processing that previously used the static buffer area is no longer required, information about the newly generated processing or processing that is no longer required The buffer allocation information can be updated by inputting the information regarding (the process of FIG. 6).

  If the present invention is used, for a process that requires a continuous area as a buffer and whose buffer size used by the process is known, a buffer can be secured as a continuous memory area on the static buffer area. As a result, high-speed processing can be executed.

  In addition, with respect to processing in which it is necessary to dynamically secure a buffer (or processing that does not require securing a buffer in the static buffer area), a buffer can be secured in the dynamic buffer area as before. In addition, since the buffer allocation information BAI output from the buffer allocation information output unit 510 is guaranteed to minimize the size of the static buffer area, the dynamic buffer area can be secured to the maximum.

<Correspondence Example between Embodiment and Invention>
(1) One or more processes that need to secure a continuous area used as a buffer on the memory (530) are represented by a set of process names ({A, B, C,...}), And buffers used by these processes Buffer size information (s (N)), a combination of processes that are not executed in parallel between these processes is expressed in an exclusive relationship, and one or more memory range candidates that can be used as buffers by the processes are buffer allocation information (BAI), the buffer allocation information (BAI) is based on the set of process names ({A, B, C,...}), The buffer size information (s (N)), and the exclusive relationship. ) Is output for each process (ST1 to ST8).

  Here, when a buffer area allocated to a process whose buffer size to be used is known is a static buffer area, and a buffer area other than this static buffer area is a dynamic buffer area, it can be used as the buffer. The memory area (532) is divided into the static buffer area (534) and the dynamic buffer area (536).

  When a specific process included in the set of process names ({A, B, C,...}) Is started, memory range candidates (stored in 520) described in the buffer allocation information (BAI) are stored. A memory range that does not overlap with a memory range used for other processing at the time of starting the specific processing (ST11), and the selected memory range is selected as the static buffer region (534). ) In the memory (530) (ST12), and the specific processing is executed using the reserved static buffer area (534) (ST13).

  (2) When a buffer area allocated to a process whose buffer size to be used is known is a static buffer area, and a buffer area other than this static buffer area is a dynamic buffer area, it can be used as the buffer. The memory area (532) is divided into the static buffer area (534) and the dynamic buffer area (536), and the memory range selected by the buffer memory range determination module (522) is the static memory area (532). Applied to the dynamic buffer area (534).

  (3) Enter the name of the first process that needs to newly secure a continuous area on the memory (530) as a buffer and the size (s (N)) of the buffer used by the first process. A process information input module (501) that performs an exclusive relationship between the first process and a process that is already included in the buffer allocation information (BAI). It can further comprise.

  (4) It further includes a processing information input module (501) for inputting a name of the second processing which no longer needs to be secured on the memory (530) as a buffer, and the buffer allocation information output module (511) ) Is based on the set of processes other than the second process and the new exclusive relation deleted from the exclusive relation that currently uses the exclusive relation related to the second process. ).

  (5) A storage module (520) for storing the buffer allocation information (BAI) is further provided, and the buffer memory range determination module (522) stores the buffer allocation information (BAI) stored in the storage module (520). ) To select the memory range.

  (6) A target memory size determination module (504) that determines a target memory size when a target value of the size of the memory area that may be used as the buffer is set as a target memory size. Can further be provided. Then, the maximum value of the sum of the buffer memory sizes used by each process of the process combinations that may be operated in parallel is set as the initial value of the target memory size, and in any order as long as the combinations of processes are not in the exclusive relationship When the buffer allocation information that can always select the buffer to be used even when processing is started is used as the request matching buffer allocation information, the request matching buffer allocation information is the buffer allocation information at the initial value of the target memory size. The target memory size determination module (504) can be configured to increase the target memory size from its initial value when not present in the information (BAI).

  (7) A target memory size determination module (504) that determines a target memory size when a target value of the size of the memory area that may be used as the buffer is set as a target memory size. And a partial problem creating module (505) for creating a partial problem from an original problem on how to determine the target memory size. When the buffer allocation information that can always select the buffer used by the process regardless of the order in which the process is started as long as the process is not in the exclusive relationship, the request matching buffer allocation information The target memory size determination module (504) can be configured such that the required memory size of the partial problem request matching buffer allocation information is set as the initial value of the target memory size of the original problem (ST3).

  (8) Information on the set of process names ({A, B, C,...}) And size information (s (N)) of the buffer used in one or more processes indicated by the set of process names The processing information input module (501) for inputting the information, the exclusive information input module (502) for inputting the information on the exclusive relationship, and the target value of the size of the memory area that may be used as the buffer as the target memory A target memory size determining module (504) for setting the target memory size, and memory allocation capable of executing the processing within the target memory size set by the target memory size determining module (504). Allocation search module (507) for searching for, processing information input module (501) and exclusive relation information input module The search range narrowing module (508) for narrowing down the search range by the buffer allocation search module (507) using the information input in (502) (information stored in 503), and the buffer allocation search module (507) An executable / impossible determination module (506) for determining whether or not the processing not in the exclusive relationship can be executed based on the buffer allocation information (BAI) obtained by the search according to (1) can be provided.

  Here, the buffer memory range determination module (522) is configured to select the buffer to be used by the process regardless of the order in which the process is started as long as the process combination is not in the exclusive relationship ( As a result, the process 524 can be executed). The buffer allocation information output module (511) is configured to output the buffer allocation information (BAI) such that the size of the static buffer area (534) is minimized.

  (9) A memory (530 in FIGS. 14 and 15) including a continuous area used as a buffer when processing a data information data stream, and a data storage device for recording and reproducing the data stream buffered in the memory ( Video equipment (TV with HDD recorder) provided with a memory allocation device (500 in FIG. 14, 500 or 500a in FIG. 15) that allocates a continuous area to be used as the buffer on the memory. A set of process names ({A, B, C,...) For one or more processes that need to secure a continuous area used as the buffer on the memory (530) in a DVD / BD recorder, notebook computer, etc. ), And a combination of processes that are not executed in parallel between the processes is represented by an exclusive relationship, and the process is a buffer. And representing one or more memory ranges candidate available buffer allocation information (BAI) and.

  In this case, the memory allocation device (500) outputs the buffer allocation information (BAI) for each process based on the set of process names ({A, B, C,...}) And the exclusive relationship. When starting a specific process included in the buffer allocation information output module (511) and the set of process names ({A, B, C,...}), It is described in the buffer allocation information (BAI). Buffer memory range determination module (522) for selecting a memory range that does not overlap with a memory range used for other processing at the time of starting the specific processing among the memory range candidates (stored in 520) And a processing module for securing the selected memory range as the buffer in the memory (530) and executing the specific processing using the secured buffer. Configured to include a Lumpur (524).

  In addition, this invention is not limited to embodiment mentioned above, In the implementation stage, it can change variously in the range which does not deviate from the summary. In addition, the embodiments may be appropriately combined as much as possible, and in that case, the combined effect can be obtained. Further, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and the effect described in the column of the effect of the invention Can be obtained as an invention.

  DESCRIPTION OF SYMBOLS 500 ... Memory allocation apparatus, 501 ... Processing information input part, 502 ... Inter-process exclusive relation input part, 503 ... Input information storage part, 504 ... Target memory size determination part, 505 ... Partial question preparation part, 506 ... Executable / non-executable Possible determination unit, 507 ... buffer allocation search unit, 508 ... search range narrowing unit, 509 ... buffer allocation determination unit, 510 ... buffer allocation information output unit, 511 ... buffer allocation information output device, 520 ... data storage unit (buffer allocation information) Storage unit), 522... Buffer memory range determination unit, 524... Processing execution unit (CPU or MPU), 530... Memory including a buffer area (memory used as a buffer).

Claims (10)

One or more processes that need to secure a continuous area used as a buffer in the memory are represented by a set of process names, a combination of processes that are not executed in parallel between the processes is represented by an exclusive relationship, and the processes can be used as a buffer. A buffer allocation information output module that outputs the buffer allocation information for each process based on the set of process names and the exclusive relationship when one or more memory range candidates are represented by buffer allocation information;
When starting a specific process included in the set of process names, the memory range candidates described in the buffer allocation information are used for other processes at the time of starting the specific process. A buffer memory range determination module for selecting a memory range that does not overlap with the memory range;
A memory allocation device comprising: a processing module that secures the selected memory range as the buffer in the memory, and executes the specific processing using the secured buffer. The memory that can be used as the buffer when a buffer area allocated to a process whose buffer size to be used is known is a static buffer area and a buffer area other than the static buffer area is a dynamic buffer area Area is divided into the static buffer area and the dynamic buffer area,
The memory allocation device according to claim 1, wherein the memory range selected by the buffer memory range determination module is applied to the static buffer area. A processing information input module for inputting a name of a first process that needs to newly secure a continuous area on the memory as a buffer, and a size of the buffer used by the first process;
The memory allocation device according to claim 1, further comprising an inter-process exclusive relationship input module that inputs an exclusive relationship between the first process and a process already included in the buffer allocation information. A processing information input module for inputting a name of the second processing that no longer needs to secure a continuous area on the memory as a buffer;
The buffer allocation information output module is based on a set of processes other than the second process and a new exclusive relationship deleted from the exclusive relationship that currently uses the exclusive relationship related to the second process. The memory allocation device of claim 1, wherein the memory allocation device is configured to output buffer allocation information. A storage module for storing the buffer allocation information;
The memory allocation device according to claim 1, wherein the buffer memory range determination module is configured to select the memory range using the buffer allocation information stored in the storage module. A target memory size determination module that determines a target memory size when a target value of the size of the memory area that may be used as the buffer is set as a target memory size;
The maximum value of the sum of the buffer memory sizes used by each process of the process combinations that may operate in parallel is set as the initial value of the target memory size. When the buffer allocation information that can always select the buffer to be used by the process even if the process is started is used as the request matching buffer allocation information, the request matching buffer allocation information is included in the buffer allocation information at the initial value of the target memory size. The memory allocation device according to claim 1, wherein the target memory size determination module is configured to increase the target memory size from its initial value when it does not exist. A target memory size determination module that determines a target memory size when a target value of the size of the area of the memory that may be used as the buffer is set as a target memory size;
A partial problem creation module for creating a partial problem from an original problem on how to determine the target memory size;
When the request allocation buffer allocation information is used as buffer allocation information that can always select a buffer to be used in any order as long as it is a combination of processes that are not in the exclusive relationship, the partial problem 7. The target memory size determination module is configured so that the required memory size of the request matching buffer allocation information is an initial value of the target memory size of the original problem. A memory allocation device according to claim 1. A process information input module for inputting information on the set of process names and size information of the buffer used in one or more processes indicated by the set of process names;
An exclusive relationship information input module for inputting the exclusive relationship information;
A target memory size determination module for setting a target memory size when a target value of a size of a memory area that may be used as the buffer is set as a target memory size;
A buffer allocation search module that searches for a memory allocation capable of performing the processing within the target memory size set by the target memory size determination module;
A search range narrowing module that narrows down a search range by the buffer allocation search module using information input by the processing information input module and the exclusive relationship information input module;
An executable / impossible determination module that determines whether or not processing that is not in the exclusive relationship is executable in the buffer allocation information obtained by the search by the buffer allocation search module;
If the buffer memory range determination module is a processing combination that is not in the exclusive relationship, the buffer memory range determination module is configured to select the buffer used by the process regardless of the order in which the process is started, and
The memory allocation device according to claim 2, wherein the buffer allocation information output module is configured to output the buffer allocation information so that a size of the static buffer area is minimized. A memory including a continuous area used as a buffer when processing a data stream of video information, a data storage device for recording and reproducing the data stream buffered in the memory, and a continuous area used as the buffer on the memory In video equipment with a memory allocation device to allocate,
One or more processes that need to secure a continuous area used as the buffer in the memory are represented by a set of process names, a combination of processes that are not executed in parallel between the processes is represented by an exclusive relationship, and the process is used as a buffer. When representing one or more possible memory range candidates in buffer allocation information,
The memory allocation device is
A buffer allocation information output module that outputs the buffer allocation information for each process based on the set of process names and the exclusive relationship;
When starting a specific process included in the set of process names, the memory range candidates described in the buffer allocation information are used for other processes at the time of starting the specific process. A buffer memory range determination module for selecting a memory range that does not overlap with the memory range;
A video apparatus comprising a processing module that secures the selected memory range in the memory as the buffer and executes the specific processing using the secured buffer. One or more processes that need to secure a continuous area used as a buffer in the memory are represented by a set of process names, a combination of processes that are not executed in parallel between the processes is represented by an exclusive relationship, and the processes can be used as a buffer A method of outputting the buffer allocation information for each process based on the set of process names and the exclusive relationship when one or more memory range candidates are represented by buffer allocation information,
The memory that can be used as the buffer when a buffer area allocated to a process with a known buffer size is a static buffer area and a buffer area other than the static buffer area is a dynamic buffer area Is divided into the static buffer area and the dynamic buffer area,
When starting a specific process included in the set of process names, the memory range candidates described in the buffer allocation information are used for other processes at the time of starting the specific process. Select a memory range that does not overlap with the memory range,
A memory allocation method that secures the selected memory range in the memory as the static buffer area, and executes the specific processing using the secured static buffer area.

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