JP2017079003A - Memory sharing system and memory sharing program - Google Patents

Abstract

An object of the present invention is to reliably avoid a deadlock caused by a memory area shortage.
A system controller 213 (first system controller) on the MFP 100 side detects a deadlock when a deadlock detector 210 uses a RAM 206 (first memory) by an image processor 209. Referring to the management table 230 managed by the shared resource manager 211 (first shared resource manager), a part of the data stored in the RAM 206 (first memory) is stored in the RAM 206 (first memory) and the user. It is moved between the terminal side (terminal side) RAM (second memory). Thereby, an empty area can be increased in the RAM 206 (first memory).
[Selection] Figure 2

Description

  The present invention relates to a memory sharing system and a memory sharing program that share memory resources between devices connected to a network.

  For example, in a memory sharing system that is an MFP (Multifunction Peripheral) such as a printer, a multi-function printer, or a multifunction device, print data received from a user terminal such as a PC via a network such as a LAN (Local Area Network) Execute print processing according to user settings.

  Incidentally, the print data is data in a page description language (PDL) format represented by PostScript (registered trademark) or PCL (Printer Control Language) (hereinafter referred to as PDL data).

  In the printing process in the memory sharing system, the received print data is temporarily converted into intermediate format data (hereinafter referred to as intermediate data) and stored in the memory, and the intermediate data stored in the memory is sequentially transferred. Read and convert to bitmap format data (hereinafter referred to as bitmap data). Further, when the intermediate data held in the memory is converted into bitmap data, the work area is expanded in the same memory area.

  By the way, for example, in a memory sharing system provided with a plurality of PDL interpreters that operate as separate tasks, a memory area as a shared resource is shared. For this reason, when one interpreter is using the memory area, the memory area for the other interpreter may be insufficient. In this case, a deadlock due to a memory area shortage may occur.

  As a means for solving such a problem, a deadlock detection method disclosed in Patent Document 1 is known. This deadlock detection method includes a management table for detecting a deadlock state caused by multiple tasks sharing a shared resource, information on a task that has transitioned to a shared resource acquisition wait state, and a task acquisition wait state. And a management information creation unit that records information on a task that is acquiring a shared resource that causes a deadlock in a management table as information for detecting a deadlock state. Exclusive control is executed.

JP 2004-341878 A

  In the deadlock detection method of Patent Document 1 described above, exclusive control of a plurality of shared resources can be performed by detecting a deadlock state easily and accurately without affecting the application program.

  However, in this deadlock detection method, when a deadlock state is detected, processing such as attempting to re-execute the task in which the deadlock has occurred is required. In this case, the task is executed from the beginning. However, when the memory area is insufficient, there is a problem that the deadlock due to the memory area shortage cannot be avoided.

  The present invention has been made in view of such a situation, and an object thereof is to provide a memory sharing system and a memory sharing program capable of solving the above-described problems.

The Molly sharing system of the present invention includes an image forming apparatus having a first memory and a terminal having a second memory and capable of transmitting data to the image forming apparatus via a network. An apparatus includes: an image processing unit that performs image processing on the data stored in the first memory; and a first shared resource management that manages information related to the data associated with information related to the terminal using a management table A deadlock detection unit that detects a deadlock when the image processing unit uses the first memory, and when the deadlock detection unit detects the deadlock, the management table is referred to, A first system control unit configured to move a part of the data between the first memory and the second memory, wherein the terminal stores the second memory. In response to a request from the first system control unit, a second shared resource management unit that manages information indicating a free area of the data and information relating to a part of the data. And a second system control unit responding with reference to information to be managed.
The first system control unit sends a rescue request to the second system control unit when the deadlock detection unit detects the deadlock, and the second system control unit Information indicating an empty area of the second memory is sent to the system control unit.
In addition, the first system control unit refers to information indicating an empty area of the second memory, and if a part of the data can be moved, sends the part of the data to the terminal, Further, the first shared resource management unit is caused to write a memory address of a part of the data in the management table, and the second system control unit is configured to send the data to the second shared resource management unit. And managing the memory address of the first memory storing a part of the memory and the memory address of the second memory storing a part of the data.
In addition, the first system control unit deletes a part of the data stored in the first memory after sending a part of the data to the terminal, and performs processing by the image processing unit. When an empty area is generated in the first memory according to progress, a part of the data moved to the second memory is received from the terminal, the management table is referred to, and the source of the first memory is It is characterized by writing in the area of the memory address.
The memory sharing system of the present invention has an image forming apparatus having a first memory, a management terminal for managing the image forming apparatus, and a second memory, and transmits data to the image forming apparatus via a network. The image forming apparatus includes: an image processing unit that performs image processing on the data stored in the first memory; and the image processing unit that uses the first memory when the image processing unit uses the first memory. A deadlock detector that detects a deadlock; and a first system controller that moves a part of the data between the first memory and the second memory; A third shared resource management unit that manages information related to the data using a management table in association with information related to the terminal, and the deadlock detection unit has detected the deadlock And a third system control unit that refers to the management table and instructs the first system control unit to move a part of the data, and the terminal has an empty space in the second memory. A second shared resource management unit that manages information indicating an area and information about a part of the data, and information that is managed by the second shared resource management unit in response to a request from the first system control unit And a second system control unit responding with reference to FIG.
In the memory sharing program of the present invention, the image processing unit performs image processing on data from the terminal stored in the first memory, and the first shared resource management unit associates the information with the terminal. A step of managing information related to the data using a management table; a step of detecting a deadlock when the image processing unit uses the first memory by a deadlock detection unit; and a first system control unit When the deadlock detection unit detects the deadlock, a step of referring to the management table and moving a part of the data between the first memory and the second memory is performed. A computer that controls the forming apparatus is executed.
In the memory sharing program of the present invention, a third shared resource management unit manages information related to data associated with a terminal by using a management table, and a third system control unit performs image processing. A step of instructing the first system control unit on the image forming apparatus side to move a part of the data with reference to the management table when the deadlock detecting section on the forming apparatus side detects the deadlock; And a computer that controls the management terminal.
In the memory sharing system and the memory sharing program of the present invention, when the first system control unit detects a deadlock when the deadlock detection unit uses the first memory by the image processing unit, the first shared resource With reference to the management table managed by the management unit, a part of the data stored in the first memory is moved between the first memory and the second memory on the terminal side. Thereby, an empty area can be increased in the first memory.

  According to the memory sharing system of the present invention, when the deadlock detection unit detects a deadlock, a part of the data stored in the first memory by the first system control unit is stored in the first memory and the terminal side. Since it is moved to and from the second memory, it is possible to increase an empty area in the first memory, and it is possible to reliably avoid a deadlock caused by a shortage of the memory area.

It is a figure which shows one Embodiment of the memory sharing system of this invention. FIG. 2 is a diagram illustrating a configuration of the MFP in FIG. 1. It is a figure which shows the structure of the user terminal of FIG. FIG. 2 is a diagram for explaining the memory area of the RAM of FIG. 2, in which FIG. 2A shows a state in which intermediate data is stored in the memory area of the RAM, and FIG. It is a figure which shows the state from which the intermediate data which C handles are deleted. 2 is a diagram illustrating another example of the memory area of the RAM in FIG. 2, in which FIG. 2A is a diagram illustrating a state in which intermediate data is stored in the memory area of the RAM, and FIG. It is a figure which shows the state from which the part of moved intermediate data is deleted. It is a figure which shows the management table which the shared resource management part of FIG. 2 manages. 3 is a flowchart for explaining a memory sharing process in the memory sharing system of FIG. 1. 3 is a flowchart for explaining a memory sharing process in the memory sharing system of FIG. 1. It is a figure for demonstrating the other example at the time of changing the structure of the memory sharing system of FIG. It is a figure which shows the structure of the management terminal of FIG.

  Hereinafter, an embodiment of a memory sharing system of the present invention will be described with reference to FIGS. An example of the image forming apparatus in the following description is, for example, an MFP (Multifunction Peripheral) which is a complex peripheral device equipped with a print function, a copy function, a FAX function, a data transmission / reception function via a network, and the like. Shall.

  First, as shown in FIG. 1, the memory sharing system includes an MFP 100 that is an image forming apparatus, and a user terminal 300 such as a PC (Personal Computer). The MFP 100 and the user terminal 300 are connected via an in-house LAN (Local Area Network) 400. Although not shown, the memory sharing system may include a document management server.

  In addition, it is assumed that RAM 206 and 313, which will be described later, which are memories mounted in the MFP 100 and the user terminal 300 in the present embodiment, are set for sharing. When the MFP 100 side avoids a deadlock due to a memory area shortage, a relief request described later is sent to all the user terminals 300 via the in-house LAN 400. When there is a response from any of the user terminals 300, a part of the data to be processed on the MFP 100 side is moved to the memory of any of the user terminals 300 that has responded. Further, when an empty area is generated in the memory according to the progress of processing on the MFP 100 side, the moved data is received and the processing is continued.

  Next, an example of the internal configuration of the MFP 100 will be described with reference to FIG. The MFP 100 includes a control unit 200, a scanner unit 220, a printer unit 221, a FAX unit 222, a panel unit 223, and an HDD 224.

  The scanner unit 220 is a device that converts an image signal of a document (not shown) read by an image sensor (not shown) into digital image data and inputs the digital image data to the control unit 200. The printer unit 221 is a device that prints an image on paper based on image data output from the control unit 200. The FAX unit 222 is a device that transmits the image data output from the control unit 200 to a facsimile machine as a counterpart through a telephone line, and receives the image data from the counterpart facsimile and inputs it into the control unit 200.

  A panel unit 223 is a device that performs display for various functions such as a print function, a copy function, a FAX function, a data transmission / reception function via a network, and the MFP 100. The HDD 224 is a storage device that stores application programs for providing various functions of the MFP 100.

  Control unit 200 is a processor that executes an image forming program, a control program, and the like to control the operation of MFP 100 as a whole. The control unit 200 includes a scanner control unit 201, a printer control unit 202, a FAX (Facsimile) control unit 203, an in-house LAN network I / F (interface) 204, a network control unit 205, a RAM (Random Access Memory) 206, and an EEPROM (Electrically). Erasable Programmable Read-Only Memory) 207, panel operation control unit 208, image processing unit 209, deadlock detection unit 210, shared resource management unit 211, HDD control unit 212, and system control unit 213. These are connected to the data bus 214.

  The scanner control unit 201 controls the reading operation of the scanner unit 220. The printer control unit 202 controls the printing operation of the printer unit 221. The FAX control unit 203 controls image data transmission / reception operations by the FAX unit 222. The network control unit 205 controls transmission / reception of data via the in-house LAN 400 via the in-house LAN network I / F 204.

  A RAM 206 (second memory) is a work memory for executing a program. The EEPROM 207 stores a control program for performing an operation check of each unit. Further, the EEPROM 207 stores log information about operations executed by the application program.

  Panel operation control unit 208 controls the display operation of panel unit 223. The image processing unit 209 performs image processing (rasterization) on the image data. The deadlock detector 210 detects a deadlock due to a memory area shortage. In this case, the deadlock detection unit 210 detects that the processing of, for example, tasks A to C described later has stopped. The deadlock detection unit 210 may detect a deadlock when, for example, a free area in a work area of the RAM 206 described later becomes equal to or less than a specific area. Although the details will be described later, the shared resource management unit 211 has a management table 230 described later, and manages the memory area of the RAM 206 and the like.

  The HDD control unit 212 controls reading and writing of data with respect to the HDD 224. The system control unit 213 (second system control unit) controls the cooperative operation of each unit. In addition, when the deadlock detection unit 210 detects a deadlock, the system control unit 213 transmits a rescue request to each user terminal 300 via the network control unit 205. Further, the system control unit 213 refers to a management table 230 described later managed by the shared resource management unit 211 in accordance with a response from one of the user terminals 300, and has a response to a part of the data stored in the RAM 206. The user terminal 300 is moved to a memory (a RAM 313 described later). At this time, the memory address of the RAM 206 storing a part of the data is also notified. Further, the system control unit 213 receives the moved data and stores it in the RAM 206 when an empty area is generated in the RAM 206 according to the progress of the processing in the image processing unit 209. As a result, the image processing unit 209 can continue the image processing on the data moved to any one of the user terminals 300. As a result, a deadlock caused by a memory area shortage is avoided.

  Next, an outline of the internal configuration of the user terminal 300 will be described with reference to FIG. The user terminal 300 includes a control unit 310 that executes a control program and controls the operation of the entire user terminal 300.

  The control unit 310 includes an in-house LAN network I / F 311, a network control unit 312, a RAM 313, an EEPROM 314, a shared resource management unit 315, and a system control unit 316. These are connected to the data bus 317.

  The network control unit 312 controls transmission / reception of data via the in-house LAN 400 via the in-house LAN network I / F 311. The RAM 313 is a work memory for executing a program. The EEPROM 314 stores a control program for checking the operation of each unit. The EEPROM 314 also stores log information about operations executed by the application program.

  The shared resource management unit 315 (second shared resource management unit) manages an empty area of the RAM 313. The shared resource management unit 315 also manages a memory address of the RAM 313 in which data received from the MFP 100 is stored. The system control unit 316 controls the cooperative operation of each unit. In addition, the system control unit 316 transmits a response to the rescue request from the MFP 100 via the network control unit 312. The response includes the terminal ID, the free capacity of the RAM 313, and the like. In addition, upon receiving data from MFP 100, system control unit 316 stores the received data in a free area of RAM 313. At this time, the system control unit 316 manages the shared resource management unit 315 with a memory address that stores a part of the data in the RAM 206 on the MFP 100 side and a memory address of the RAM 313 that stores a part of the data. Let

  Next, the memory area of the RAM 206 on the MFP 100 side will be described with reference to FIG. First, when the MFP 100 performs print processing on print data received from the user terminal 300, for example, the print data received by the image processing unit 209 is once converted into intermediate format data (hereinafter referred to as intermediate data). Then, the intermediate data converted by the system control unit 213 is stored in the memory area of the RAM 206.

  Here, FIG. 4A shows a state in which the intermediate data is stored in, for example, addresses a0 to a5, which are memory addresses in the memory area of the RAM 206. Moreover, the state from address a6 to address an is the work area. In FIG. 4A, for convenience of explanation, task A is responsible for intermediate data from addresses a0 to a1, task B is responsible for intermediate data from addresses a2 to a3, and addresses a4 to a5. This shows a state where task C is responsible for intermediate data.

  In general, when any of the tasks A to C occupies the work area by the exclusive control, the process in which the other tasks A to C wait for the work area to be released is repeated. Here, for example, if the work area is insufficient during the processing of task A, the processing of task A is interrupted and a deadlock occurs. At this time, the deadlock detector 210 detects a deadlock. The deadlock detection unit 210 may detect a deadlock when, for example, the free area of the work area in the RAM 206 becomes equal to or less than a specific area during the processing of task A.

  Further, when the deadlock detection unit 210 detects a deadlock, the system control unit 213 sends a rescue request to all the user terminals 300 via the in-house LAN 400 in order to avoid deadlock due to insufficient memory area. When there is a response from the user terminal 300, the free capacity of the RAM 313 included in the response is confirmed, and a part of the intermediate data is moved to the RAM 313 of the user terminal 300.

  FIG. 4B shows a state in which, for example, intermediate data handled by the task C is moved to one of the user terminals 300 in order to avoid a deadlock due to a memory area shortage during the processing of the task A, for example. Yes. That is, when the intermediate data handled by task C is moved to any of the user terminals 300, the intermediate data from address a4 to address a5 handled by task C is deleted, so that the work area is changed from address a4 to address a5. It can be opened (increased) by the amount. Thereby, for example, the shortage of the work area during the processing of task A is solved, and the deadlock caused by the shortage of the memory area is avoided.

  FIG. 4B shows a state in which the intermediate data from address a4 to a5 addressed by task C is moved, but the intermediate data from address a2 to a3 addressed by task B is moved. Also good. In addition, a part of the intermediate data from address a4 to a5 address handled by task C may be moved, or a part of the intermediate data from address a2 to a3 addressed by task B may be moved. In any case, it is only necessary to secure a work area that can avoid a deadlock due to a shortage of the memory area of task A, for example, during processing.

  4 shows a case where a plurality of tasks A to C are responsible for processing intermediate data stored in the memory area of the RAM 206. For example, as shown in FIG. There may be a case where only the task A is in charge of processing the intermediate data stored in the area.

  In this case, as shown in FIG. 5 (b), the intermediate data that is a part of the intermediate data, for example, the intermediate data from address a4 to address a5 is moved to one of the user terminals 300, resulting in insufficient memory area. Deadlock can be avoided.

  Next, a management table managed by the shared resource management unit 211 will be described with reference to FIG. First, the management table 230 managed by the shared resource management unit 211 includes, for example, a terminal ID (identification) item 231, a response presence / absence item 232, a free space item 233, and a memory address item 234 of the moved intermediate data. Have. The shared resource management unit 211 manages the presence / absence of a response, the free capacity, and the memory address of the moved intermediate data in association with the terminal ID.

  Here, the shared resource management unit 211 writes an identifier for identifying each user terminal 300 in the item 231 of the terminal ID. Further, the shared resource management unit 211 writes the presence / absence of the rescue request from the MFP 100 in the response presence / absence item 232. Further, the shared resource management unit 211 writes the free capacity of the RAM 313 on the user terminal 300 side that has responded to the free capacity item 233. Further, the shared resource management unit 211 writes the memory address of the intermediate data moved from the RAM 206 on the MFP 100 side in the item 234 of the memory address of the moved intermediate data.

  In addition, when the shared resource management unit 211 receives a response from the user terminal 300 to the rescue request from the MFP 100 and receives intermediate data moved to one of the user terminals 300, the content of the management table 230 Update. In this case, the shared resource management unit 211 deletes the contents written in the response presence / absence item 232, the free space item 233, and the moved intermediate data memory address item 234, respectively.

  Incidentally, FIG. 6 shows that when the terminal ID is A001, A002, or A00n, “Yes” indicating that there is a response is written in the response presence / absence item 232. In addition, the free capacity item 233 indicates that 70 MB, 800 MB, and 50 MB of free capacity are written in association with the terminal IDs of A001, A002, and A00n that have responded, respectively. Further, it is shown that the memory address of the intermediate data moved from the RAM 206, for example, addresses a4 to a5, is written in the memory address item 234 of the moved intermediate data. Then, it is confirmed that the intermediate data is moved by confirming that the memory address of the data moved from the RAM 206 is written in the memory address item 234 of the intermediate data moved by the system control unit 213. Can be identified.

  Here, it is assumed that the system control unit 213 determines that the data amount handled by the task B is 100 MB, for example, and the data amount handled by the task C is 60 MB, for example. In this case, the system control unit 213 determines that the task B data amount (100 MB) is movable because the free capacity of the user terminal 300 with the terminal ID (A002) is 800 MB. Further, the system control unit 213 determines that the data amount of task C (60 MB) is movable because the free capacity of the user terminal 300 with the terminal ID (A001, A002) is 70 MB and 800 MB, respectively.

  In this case, the intermediate data of task B and the intermediate data of task C can both be moved, but considering the processing time related to the movement of data, the intermediate data of task C having a small data amount (60 MB). May be moved. Further, the transfer destination of the intermediate data of task C may be the user terminal 300 of either the terminal ID (A001) having a free capacity of 70 MB or the terminal ID (A002) having 800 MB. Similarly, considering the processing time related to the movement of the intermediate data, the intermediate data of the task C may be moved to the user terminal 300 that has previously responded.

  Furthermore, as described above, a work area that can avoid a deadlock that is being processed, for example, due to a shortage of the memory area of task A, may be secured. A part of the intermediate data of B may be moved.

  Note that the system control unit 213 also sends the memory address of the RAM 206 when moving the intermediate data to the user terminal 300. That is, for example, when the intermediate data of task C is moved to the user terminal 300, the memory address (address a4 to a5) of the intermediate data of task C is also sent.

  As a result, the user terminal 300 receiving the intermediate data of task C can manage the memory address stored in the RAM 313 and the memory address of the intermediate data of task C (addresses a4 to a5) in association with each other. it can. Thereby, when there is a reply request for intermediate data from the MFP 100 side, the intermediate data of task C stored in the RAM 313 can be reliably sent back.

  In addition, after sending the task C intermediate data, the system control unit 213 deletes and releases the task C intermediate data at addresses a4 to a5 as shown in FIG. 4B. Further, the system control unit 213 can write the intermediate data received from the user terminal 300 to the original address of the RAM 206 by referring to the memory address in the item 234 of the memory address of the moved intermediate data.

  Next, the memory sharing process will be described with reference to FIGS. In the following description, it is assumed that task A of the image processing unit 209 performs processing.

(Step S101)
First, the system control unit 213 determines whether the deadlock detection unit 210 has detected a deadlock. As described in FIG. 4A, the deadlock detection unit 210 is responsible for the intermediate data from the address a0 to the address a1 and the task B is responsible for the intermediate data from the address a2 to the address a3. Assume that task C is responsible for intermediate data from addresses a4 to a5. Further, it is assumed that the deadlock detection unit 210 detects a deadlock when the work area of the RAM 206 is exhausted and the processing of the task A is stopped while the task A of the image processing unit 209 is being processed. As described above, the deadlock detection unit 210 may detect a deadlock when the work area of the RAM 206 is equal to or less than a specific area while the task A of the image processing unit 209 is being processed. .
If the system control unit 213 determines that it is not a deadlock (step S101: No), the system control unit 213 proceeds to step S102. On the other hand, if the system control unit 213 determines that it is a deadlock (step S101: Yes), the system control unit 213 proceeds to step S105.

(Step S102)
The system control unit 213 determines whether the data (intermediate data) is moved to another terminal (user terminal 300). In this case, the system control unit 213 refers to the management table 230 illustrated in FIG. 6 managed by the shared resource management unit 211. If the memory address is not written in the memory address item 234 of the moved data (intermediate data), the system control unit 213 has not moved the data (intermediate data) to another terminal (user terminal 300). It judges (step S102: No) and transfers to step S103.
In contrast, if the memory address is written in the memory address field 234 of the moved data (intermediate data) in the management table 230, the system control unit 213 transfers the data (intermediate data) to another terminal (user terminal). 300) (step S102: Yes), the process proceeds to step S111 in FIG.
That is, as shown in FIG. 6, when the addresses a4 to a5, which are memory addresses, are written in the memory address item 234 of the moved data (intermediate data), the system control unit 213 displays the data (intermediate data). ) Is moved to another terminal (user terminal 300). Further, the system control unit 213 identifies the user terminal 300 that has moved the data (intermediate data) by confirming the terminal ID (A002) in which the memory address is written.

(Step S103)
Task A of the image processing unit 209 continues processing.

(Step S104)
The system control unit 213 determines whether the processing by the image processing unit 209 has ended. In this case, the system control unit 213 determines that the processing by the image processing unit 209 has ended when there is a notification from the image processing unit 209 that the tasks A to C have been completed (step S104: Yes). On the other hand, the system control unit 213 determines that the processing by the image processing unit 209 has not ended if there is no notification from the image processing unit 209 that the tasks A to C have been completed (step S104: No). The process proceeds to step S101.

(Step S105)
When the deadlock detection unit 210 detects a deadlock, the system control unit 213 sends a rescue request to all user terminals 300 via the in-house LAN 400.

(Step S106)
The system control unit 213 waits for a response from the user terminal 300 (step S106: No). If there is a response from the user terminal 300 (step S106: Yes), the system control unit 213 proceeds to step S107.

(Step S107)
Upon receiving a response from the user terminal 300, the system control unit 213 causes the shared resource management unit 211 to update the contents of the management table 230 illustrated in FIG.
In this case, when there is a response from the user terminal 300 with the terminal IDs A001, A002, and A00n, the shared resource management unit 211 writes “Yes” in the response presence / absence item 232 corresponding to each terminal ID. The shared resource management unit 211 writes “none” in the response presence / absence item 232 for the terminal ID A003 for which there is no response.
In addition, the shared resource management unit 211 writes the free capacity of the RAM 313 on the user terminal 300 side included in the response in the free capacity item 233. Incidentally, FIG. 6 shows that when the terminal IDs are A001, A002, and A00n, 70 MB, 800 MB, and 50 MB of free space are included in the response, respectively.

(Step S108)
The system control unit 213 determines the data amount handled by the task B and the data amount handled by the task C, excluding the task A being processed, in the memory area of the RAM 206 shown in FIG.
Here, it is assumed that the system control unit 213 determines that the data amount handled by the task B is 100 MB, for example, and the data amount handled by the task C is 60 MB, for example. In this case, the system control unit 213 determines that the task B data amount (100 MB) is movable because the free capacity of the user terminal 300 with the terminal ID (A002) is 800 MB. Further, the system control unit 213 determines that the data amount of task C (60 MB) is movable because the free capacity of the user terminal 300 with the terminal ID (A001, A002) is 70 MB and 800 MB, respectively.
In this case, both the task B data (intermediate data) and the task C data (intermediate data) can be moved, but considering the processing time involved in the movement of the data (intermediate data), the amount of data Data of task C (intermediate data) with a small (60 MB) may be moved. Further, the destination of the task C data (intermediate data) may be the user terminal 300 of either the terminal ID (A001) or the terminal ID (A002) having free capacity of 70 MB and 800 MB, respectively. However, in the same manner as described above, considering the processing time related to the movement of data (intermediate data), the data of task C (intermediate data) may be moved to the user terminal 300 that has responded earlier.
Then, for example, when the response of the user terminal 300 with the terminal ID (A002) comes first, the system control unit 213 sends, for example, data of task C (intermediate data) to the user terminal 300 with the terminal ID (A002).

(Step S109)
As shown in FIG. 4B, the system control unit 213 deletes data (intermediate data) from address a4 to address a5, which is handled by the moved task C in the RAM 206. As a result, the work area can be released (increased) by an amount from address a4 to address a5.

(Step S110)
The image processing unit 209 uses the released memory area and continues the task A process. Thereby, the shortage of the work area during the processing of task A is solved, and the deadlock caused by the shortage of the memory area is avoided.

(Step S111)
In step S <b> 111 of FIG. 8, the system control unit 213 determines whether an empty area has occurred in the RAM 206. In other words, the system control unit 213 releases the work area when the processing of the task A is completed, for example. For this reason, the system control unit 213 waits until the processing of the task A is completed (step S111: No), for example, and when the processing of the task A is completed and the work area is released, for example, it is determined that an empty area is generated in the RAM 206 (Step S111: Yes) and the process proceeds to Step S112.

(Step S112)
The system control unit 213 refers to the management table 230 managed by the shared resource management unit 211, and sends a data (intermediate data) return request to the user terminal 300 whose terminal ID is A002 to which the data (intermediate data) has been moved. .
In this case, the reply request includes information indicating data (intermediate data) from address a4 to address a5, which are memory addresses.
As a result, the user terminal 300 that has received the reply request associates and manages the memory address stored in the RAM 313 and the memory address of the task C data (intermediate data) (addresses a4 to a5). Therefore, the data of task C (intermediate data) stored in the RAM 313 can be reliably sent back.

(Step S113)
The system control unit 213 waits until data (intermediate data) is received (step S113: No). When data (intermediate data) is received (step S113: Yes), the system control unit 213 proceeds to step S114.

(Step S114)
Upon receiving the data (intermediate data), the system control unit 213 causes the shared resource management unit 211 to update the contents of the management table 230 shown in FIG.
In this case, the shared resource management unit 211 deletes the contents written in the response table item 232, the free space item 233, and the memory address item 234 of the moved data (intermediate data) in the management table 230. .

(Step S115)
The system control unit 213 writes the received data (intermediate data) in the memory area. In this case, the system control unit 213 writes the received data (intermediate data) to addresses a4 to a5, which are the original memory addresses of the RAM 260, and proceeds to step S103.
As a result, the image processing unit 209 can continue processing by the task B and the task C.

  As described above, in the present embodiment, the system controller 213 (first system controller) on the MFP 100 side causes the deadlock detector 210 to use the RAM 206 (first memory) by the image processor 209 when the deadlock detector 210 uses the RAM 206. When a lock is detected, the management table 230 managed by the shared resource management unit 211 (first shared resource management unit) is referred to, and a part of the data (intermediate data) stored in the RAM 206 (first memory) is stored. It is moved between the RAM 206 (first memory) and the RAM 313 (second memory) on the user terminal 300 side (terminal side). As a result, an empty area can be increased in the RAM 206 (first memory), and a deadlock due to a shortage of the memory area can be reliably avoided.

  In the present exemplary embodiment, as illustrated in FIG. 1, the memory sharing system has been described as including the MFP 100 that is the image forming apparatus and the user terminal 300, but the present invention is not limited to this example. As shown, a management terminal 500 that manages the MFP 100 may be provided.

  In this case, as illustrated in FIG. 10, the management terminal 500 includes a control unit 510 that executes a control program and controls the operation of the entire management terminal 500. The control unit 510 includes an in-house LAN network I / F 511, a network control unit 512, a RAM 513, an EEPROM 514, a shared resource management unit 515, and a system control unit 516. These are connected to the data bus 517. These operations are substantially the same as the operations of the respective units in the control unit 200 of the MFP 100 described with reference to FIG.

  That is, by arranging a shared resource management unit 515 (third shared resource management unit) equivalent to the shared resource management unit 211 shown in FIG. 2 on the management terminal 500 side, the system control unit 516 (third system control) Part) can manage the MFP 100. In this case, the shared resource management unit 211 shown in FIG. 2 can be omitted. Further, the deadlock detection unit 210 shown in FIG. 2 can be arranged on the management terminal 500 side. In this case, the deadlock of the MFP 100 can be detected on the management terminal 500 side, and processing related to the deadlock detection on the MFP 100 side can be omitted.

  In addition, as illustrated in FIG. 1, the memory sharing system has been described as including the MFP 100 as the image forming apparatus and the user terminal 300, but other terminals that can transmit and receive data via the in-house LAN 400. May be provided. Other terminals may be mobile terminals such as smart phones, printers, servers, and the like.

100 MFP
200, 310, 510 Control unit 201 Scanner control unit 202 Printer control unit 203 FAX control unit 204, 311, 511 Internal LAN network I / F
205, 312, 512 Network control unit 206, 313, 513 RAM
207, 314, 514 EEPROM
208 Panel operation control unit 209 Image processing unit 210 Deadlock detection unit 211, 315, 515 Shared resource management unit 212 HDD control unit 213, 316, 516 System control unit 214, 317, 517 Data bus 220 Scanner unit 221 Printer unit 222 FAX Part 223 panel part 224 HDD
230 Management tables 231 to 234 Item 300 User terminal 400 Internal LAN
500 Management terminal

Claims (7)

An image forming apparatus having a first memory;
A terminal having a second memory and capable of transmitting data to the image forming apparatus via a network;
The image forming apparatus includes:
An image processing unit that performs image processing on the data stored in the first memory;
A first shared resource management unit that manages information related to the data associated with information related to the terminal using a management table;
A deadlock detection unit that detects a deadlock when the image processing unit uses the first memory;
When the deadlock detection unit detects the deadlock, the first system control unit refers to the management table and moves a part of the data between the first memory and the second memory. And
The terminal
A second shared resource management unit for managing information indicating a free area of the second memory and information on a part of the data;
A memory sharing system comprising: a second system control unit that responds to a request from the first system control unit with reference to information managed by the second shared resource management unit. When the deadlock detection unit detects the deadlock, the first system control unit sends a rescue request to the second system control unit,
The memory sharing system according to claim 1, wherein the second system control unit sends information indicating an empty area of the second memory to the first system control unit. The first system control unit refers to information indicating an empty area of the second memory, and if a part of the data can be moved, sends the part of the data to the terminal, and further Causing the first shared resource management unit to write a partial memory address of the data in the management table;
The second system control unit stores the memory address of the first memory storing a part of the data and the part of the data in the second shared resource management unit. The memory sharing system according to claim 2, wherein the memory address of the second memory is managed. The first system control unit includes:
After sending a part of the data to the terminal, deleting the part of the data stored in the first memory;
When an empty area occurs in the first memory in accordance with the progress of the processing by the image processing unit, a part of the data moved to the second memory is received from the terminal, and the management table is referred to. The memory sharing system according to claim 3, wherein writing is performed in an area of an original memory address of the first memory. An image forming apparatus having a first memory;
A management terminal for managing the image forming apparatus;
A terminal having a second memory and capable of transmitting data to the image forming apparatus via a network;
The image forming apparatus includes:
An image processing unit that performs image processing on the data stored in the first memory;
A deadlock detection unit that detects a deadlock when the image processing unit uses the first memory;
A first system controller that moves a portion of the data between the first memory and the second memory;
The management terminal
A third shared resource management unit that manages information related to the data using a management table in association with information related to the terminal;
When the deadlock detection unit detects the deadlock, the management table is referred to and a third system control unit is provided that instructs the first system control unit to move part of the data. And
The terminal
A second shared resource management unit for managing information indicating a free area of the second memory and information on a part of the data;
A memory sharing system comprising: a second system control unit that responds to a request from the first system control unit with reference to information managed by the second shared resource management unit. Performing image processing on data from the terminal stored in the first memory by the image processing unit;
Managing information related to the data associated with the information related to the terminal by using a management table by the first shared resource management unit;
A step of detecting a deadlock when the image processing unit uses the first memory by a deadlock detection unit;
When the deadlock detection unit detects the deadlock by the first system control unit, the management table is referred to and a part of the data is moved between the first memory and the second memory. And a step of causing the computer that controls the image forming apparatus to execute the step of causing the image forming apparatus to execute the process. A third shared resource management unit managing information related to data from the terminal in association with information related to the terminal using a management table;
When the third system control unit detects a deadlock by the deadlock detection unit on the image forming apparatus side, the management table is referred to and the first system control unit on the image forming apparatus side stores the one of the data. A memory sharing program that causes a computer that controls a management terminal to execute a step of instructing movement of a section.

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