JP2013161108A - Information processing device, information processing method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information processing device, an information processing method, and a program that are capable of alleviating a flow control state in a computer in which a STREAMS mechanism is implemented.SOLUTION: An information processing device 10 comprises a module insertion unit 11 that, into a data path (stream) 20 which is constructed in a computer 50 and on which a message is transceived between a process 41 and a driver 23, inserts a data amount adjustment module 12 for adjusting the data amount of the message on the data path 20.

Description

  The present invention relates to an information processing apparatus, an information processing method, and a program used for a computer in which a STREAMS mechanism is implemented.

  Conventionally, in the UNIX operating system, the STREAMS mechanism has been used as part of the kernel functions. The STREAMS mechanism, as well as various types of device drivers, has become the de facto industry standard framework for implementing network protocols in data communications.

  In the STREAMS mechanism, a “stream” is a bidirectional data path provided between a user-level process such as an application program and a device driver in the kernel, and means a full-duplex path. .

  Here, the stream will be described with reference to FIG. FIG. 8 is a conceptual diagram for explaining a stream. As shown in FIG. 8, the stream 70 includes a stream head 71, a processing module 72, and a driver 73 constructed by program modules.

  Since each module includes a set of queues, the stream 70 can be said to be composed of a set of queues that are linearly connected. Each set of queues includes a write queue (also referred to as “WQ”) and a read queue (also referred to as “RQ”).

  When a process in the user space (not shown in FIG. 8) writes an output message 74 to the stream head 71, the kernel sends the message to the lower write queue. When the driver 73 receives the input message 74, the kernel sends the message 74 to the above read queue.

  The basic concept of such a stream is disclosed in Non-Patent Document 1 described by designer Ritchie, D.M. In addition, the current standard concept is improved from that of the basic concept. The concept of the current STREAMS mechanism is disclosed in Non-Patent Document 2, for example.

Ritchie, D.M., supervised by Haruhisa Ishida, translated by Kimoto Hasebe and Kentaro Shimizu, “Stream I / O System”, “UNIX Original”, Personal Media, 1986, p. 365-379 Maurice J. Bach, Text by Saka, Translated by Yoshikatsu Tada, Translated by Jun Murai, “Designing UNIX Kernels”, Kyoritsu Shuppan, 1990, p.291-297

  By the way, in a computer in which such a STREAMS mechanism is mounted, if the amount of transmission / reception data in the stream 70 becomes too large, the computer may fall into a flow control state. In the example of FIG. 8 described above, a message group is accumulated in each write queue and each read queue constituting the stream 70. In each write queue and each read queue, the amount of data reaches the high water value of the queue, and is in a “QFULL” state.

  Whether to fall into such a flow control state depends on the data processing speed on the driver side (write side) and the data processing speed on the application side (read side). Therefore, depending on these processing speeds, a chronic flow control state may continue. For this reason, computers that implement the STREAMS mechanism are required to relax this chronic flow control state.

  An object of the present invention is to provide an information processing apparatus, an information processing method, and a program that can alleviate the above-described problems and can relax a flow control state in a computer that implements a STREAMS mechanism.

  In order to achieve the above object, an information processing apparatus according to an aspect of the present invention is configured in a computer and transmits / receives a message between a process and a driver. And a module insertion unit for inserting a data amount adjustment module for adjusting the data amount.

  In order to achieve the above object, an information processing method according to an aspect of the present invention is configured in a computer, and transmits / receives a message between a process and a driver. A data amount adjustment module for adjusting the data amount of the message is inserted.

  Furthermore, in order to achieve the above object, a program according to one aspect of the present invention is constructed by a computer in the computer, and transmits / receives a message between a process and a driver. The step of inserting a data amount adjustment module for adjusting the data amount of the message is executed.

  As described above, according to the present invention, the flow control state can be relaxed in the computer system in which the STREAMS mechanism is mounted.

FIG. 1 is a block diagram showing a configuration of an information processing apparatus according to an embodiment of the present invention. FIG. 2 is a diagram illustrating an example of the data amount adjustment module inserted in the present embodiment. FIG. 3 is a flowchart showing the operation of the information processing apparatus according to the embodiment of the invention. FIG. 4 is a diagram illustrating a state before and after the data amount adjustment module is inserted into the data path. FIG. 5 is a diagram illustrating an example of a program that implements the information processing apparatus according to the present embodiment. FIG. 6 is a diagram for explaining the effect of the present embodiment. FIG. 7 is a block diagram illustrating an example of a computer that implements the information processing apparatus according to the embodiment of the present invention. FIG. 8 is a conceptual diagram for explaining a stream.

(Embodiment)
Hereinafter, an information processing apparatus, an information processing method, and a program according to an embodiment of the present invention will be described with reference to FIGS.

[Device configuration]
First, the configuration of the information processing apparatus in the present embodiment will be described. FIG. 1 is a block diagram showing a configuration of an information processing apparatus according to an embodiment of the present invention.

  As shown in FIG. 1, the information processing apparatus 10 according to the present embodiment is an apparatus used in a computer 50 in which an operating system (OS) 30 is constructed. Specifically, the information processing apparatus 10 is constructed by a program that operates on the OS 30. In the present embodiment, the operating system is UNIX (registered trademark).

  As illustrated in FIG. 1, the information processing apparatus 10 includes a module insertion unit 11. The module insertion unit 11 inserts the data amount adjustment module 12 that adjusts the data amount of the message in the data path 20 constructed in the OS 30.

  The data path 20 is a path used for transmitting and receiving messages between the process 41 executed by the application program 40 and the driver 23. In the present embodiment, the data path 20 is a “stream” provided by the STREAMS mechanism installed in the OS 30.

  In this embodiment, the data amount adjustment module 12 has a function of storing messages until the set data amount is reached, and adjusts the data amount of messages flowing through the data path 20 by this function.

  In this way, in the information processing apparatus 10, the amount of data flowing through the “stream” that is the data path 20 is adjusted. Will be mitigated.

  Further, since the data amount adjustment module 12 that adjusts the data amount is a part of the data path 20, the flow control state is relaxed by the function of the OS 30. Conventionally, it is impossible to relax the flow control state by the function of the OS 30. In FIG. 1, reference numeral 60 denotes a user terminal that operates the application program 40.

  Here, the configuration of the information processing apparatus 10 in the present embodiment will be described more specifically. As shown in FIG. 1, in the present embodiment, the data path 20 includes a stream head 21, a processing module 22, and a driver 23 constructed by program modules.

  Among these, the stream head 21 is a module that functions as a window for calling from the process 41 executed by the application program 40. The processing module 22 is a module that executes processing according to the process 41. The driver 23 is a module for operating devices such as a printing machine and a network device.

  The stream head 21, the processing module 22, and the driver 23 each include a write queue (write queue: WQ) and a read queue (read queue: RQ). The operation of each queue is the same as that in the example of FIG.

  Further, as shown in FIG. 1, the module insertion unit 11 inserts the data amount adjustment module 12 between modules constituting the data path 20. The data amount adjusting module 12 then corresponds to the queue for writing (denoted as “WQ” in FIG. 1) and the queue corresponding to the queue for reading (denoted as “RQ” in FIG. 1). It has. The data amount adjustment module 12 can accumulate messages until the set data amount is reached by each of these corresponding queues.

[Specific example of data volume adjustment module]
Here, a specific example of the data amount adjustment module 12 will be described with reference to FIG. FIG. 2 is a diagram illustrating an example of the data amount adjustment module inserted in the present embodiment.

  In the example of FIG. 2, only the driver entry routine of the data amount adjustment module 12 is shown. Specifically, only “xxx_wput ()” that is a write-side put procedure is shown. Here, the prefix “xxx_” is the module name of the module that constructs the data path 20, and the character string is not particularly limited as long as it is suitable for the module name. Note that the format of the driver entry routine conforms to “UNIX System V Release 4”, and the same applies to the following.

  Further, as shown in FIG. 2, “xxx_wput ()” has acquired, as processing parts, a “GET_HIWAT command” for acquiring a high water value, a “GET_LOWAT command” for acquiring a low water value, and a high water value. It has a “SET_HIWAT command” that sets the value and a “SET_LOWAT command” that sets the low water value to the acquired value. These commands are executed from the system call ioctl (I_STR).

  “Xxx_wput ()” puts the message into its own write queue except for a special message such as the message type M_FLUSH. For this reason, in the example of FIG. 2, the data amount adjustment module executes a process of storing messages in the write queue until the data amount reaches the high water value.

  Next, “xxx_wsrv ()” that is a write-side service procedure, “xxx_rput ()” that is a read-side put procedure, and “xxx_rsrv ()” that is a read-side service procedure will be described. These illustrations in FIG. 2 are omitted.

  First, the write side service procedure “xxx_wsrv ()” can be implemented simply by executing putnext () after executing geq () without performing any processing (processing) on the message. It ’s fine.

  The read-side put procedure “xxx_rput ()” may be implemented by putting a message into its own read queue except for a special message such as the message type M_FLUSH. As a result, the data amount adjustment module executes a process of storing messages in the read queue until the data amount reaches the high water value.

  And for “xxx_rsrv ()” which is a read side service procedure, execute putqt () after executing getq () without performing any special processing (processing) on the message like the write side service procedure. Just a simple implementation to do.

  Note that the high water value and low water value on the write side and read side of the data amount adjustment module are sufficient in the default state compared to the high water value and low water value of other modules and drivers constituting the data path 20. It is preferable to set so as to increase. The specific value is appropriately set based on the processing speed of the data processing on the driver side and the processing speed of the data processing on the application side.

  Since the data amount adjustment module 12 can set the high water value and the low water value of each queue constituting the data amount adjustment module 12 in this way, in this embodiment, the module insertion unit 11 performs the data amount adjustment. The amount of message data that can be stored in the module 12 can be changed.

[Device operation]
Next, the operation of the information processing apparatus according to the embodiment of the present invention will be described with reference to FIGS. FIG. 3 is a flowchart showing the operation of the information processing apparatus according to the embodiment of the invention. FIG. 4 is a diagram illustrating a state before and after the data amount adjustment module is inserted into the data path.

  In the following description, FIGS. 1 and 2 are referred to as appropriate. Furthermore, in this embodiment, the information processing method is performed by operating the information processing apparatus. Therefore, the description of the information processing method in the present embodiment is replaced with the following description of the operation of the information processing apparatus 10.

  As shown in FIG. 3, first, the module insertion unit 11 receives an instruction to insert a data amount adjustment module from the process 41 (step A1), and inserts the data amount adjustment module 12 into the data path 20 (step A2). .

  Specifically, in the present embodiment, when the system call ioctl (I_PUSH) is performed by the process 41, the module insertion unit 11 inserts a data amount adjustment module into the data path 20.

  Next, the module insertion unit 11 acquires a preset high water value, and sets the acquired high water value in a queue constituting the data amount adjustment module 12 (step A3). Subsequently, the module insertion unit 11 acquires a preset low water value, and sets the acquired low water value in a queue constituting the data amount adjustment module 12 (step A4).

  When steps A1 to A4 are executed, the data amount adjustment module 12 is inserted in the data path (stream) 20, as shown in FIG. 4 (see the right side of FIG. 4). In the example of FIG. 4, as in the example of FIG. 1, the data amount adjustment module 12 is inserted immediately below the stream head 21. After the execution of step A4, the process in the module insertion unit 11 ends.

  In the example of FIG. 3, the system call ioctl (I_PUSH) by the process 41 is used as a trigger for inserting the data amount adjustment module 12, but the present embodiment is not limited to this.

  For example, the data amount adjustment module 12 is inserted when the driver designated in advance as the driver 23 that needs to insert the data amount adjustment module is opened by the execution of the autopush command by the process 41. It may be.

  The data amount adjustment module 12 is inserted when the process 41 executes “strchg -h [data amount adjustment module name] <[driver device file name]” by using the strchg command. May be performed on a particular open stream.

  However, the high water value and low water value of the data amount adjustment module 12 can be acquired and set only when the process 41 issues a system call ioctl (I_STR).

[program]
Moreover, the program in this Embodiment should just be a program which makes a computer perform step A1-A4 shown in FIG. By installing and executing this program in the computer 50, the information processing apparatus 10 and the information processing method in the present embodiment can be realized. In this case, a CPU (Central Processing Unit) of the computer functions as the module insertion unit 11 and performs processing. Furthermore, in the present embodiment, the program that implements the information processing apparatus 10 may be a part of the application program 40.

  Here, an example of a program in the present embodiment will be described with reference to FIG. FIG. 5 is a diagram illustrating an example of a program that implements the information processing apparatus according to the present embodiment. In the example of FIG. 5, the program is implemented as a module in the application program 40.

  In the example of FIG. 5, as an example of processing executed by the program, the stream driver is opened, the data amount adjustment module 12 is pushed, the data amount adjustment module 12 obtains the high water value, and the data amount adjustment module 12 is high. The water value setting process is shown.

[Effects of the embodiment]
As described above, according to the present embodiment, since the data amount adjustment module 12 can be inserted into a stream that easily falls into the flow control state, the flow control state can be relaxed by the function on the OS side. Will be. This point will be described with reference to FIG. FIG. 6 is a diagram for explaining the effect of the present embodiment.

  As shown in FIG. 6, when the data amount adjustment module 12 is inserted into the data path (stream) 20, a part of the message 24 is temporarily accumulated in the data amount adjustment module. Therefore, even if the amount of data transmitted and received is the same as in the example shown in FIG. 8, the QFULL state is relaxed in each queue on the application side (write side in FIG. 6) and device side (read side in FIG. 6). Is done.

  In this embodiment, since the high water value and the low water value of the data amount adjustment module 12 can be changed, it is possible to reliably relax the flow control state for a stream in which the flow control state is likely to occur. It becomes possible. In addition, in the present embodiment, since the data amount adjustment module can be inserted for each stream, it is possible to select whether or not to use the data amount adjustment module for each stream driver.

[Modification]
In the example of FIGS. 1 to 6, only one data amount adjustment module is inserted. However, in the present embodiment, the number of data amount adjustment modules 12 is not limited. For example, a plurality of data amount adjustment modules 12 may be inserted for a stream having a chronic flow control occurrence state.

  However, in the above case, acquisition and setting of the high water value and the low water value by “ioctl (I_STR)” are limited only to the flow control mitigation module closest to the stream head.

  The data amount adjustment module 12 is configured not to perform data processing (processing of data in the message) as a stream module. Therefore, a plurality of data amount adjustment modules can be inserted into the same stream until the value (number) set by the kernel parameter NSTRPUSH is reached.

[Computer]
Here, a computer 50 that implements the information processing apparatus 10 by executing the program according to the embodiment will be described with reference to FIG. FIG. 7 is a block diagram illustrating an example of a computer that implements the information processing apparatus according to the embodiment of the present invention.

  As shown in FIG. 7, the computer 110 includes a CPU 111, a main memory 112, a storage device 113, an input interface 114, a display controller 115, a data reader / writer 116, and a communication interface 117. These units are connected to each other via a bus 121 so that data communication is possible.

  The CPU 111 performs various calculations by developing the program (code) in the present embodiment stored in the storage device 113 in the main memory 112 and executing them in a predetermined order. The main memory 112 is typically a volatile storage device such as a DRAM (Dynamic Random Access Memory). Further, the program in the present embodiment is provided in a state of being stored in a computer-readable recording medium 120. Note that the program in the present embodiment may be distributed on the Internet connected via the communication interface 117.

  Specific examples of the storage device 113 include a hard disk and a semiconductor storage device such as a flash memory. The input interface 114 mediates data transmission between the CPU 111 and an input device 118 such as a keyboard and a mouse. The display controller 115 is connected to the display device 119 and controls display on the display device 119. The data reader / writer 116 mediates data transmission between the CPU 111 and the recording medium 120, and reads a program from the recording medium 120 and writes a processing result in the computer 110 to the recording medium 120. The communication interface 117 mediates data transmission between the CPU 111 and another computer.

  Specific examples of the recording medium 120 include general-purpose semiconductor storage devices such as CF (Compact Flash (registered trademark)) and SD (Secure Digital), magnetic storage media such as a flexible disk, or CD- An optical storage medium such as ROM (Compact Disk Read Only Memory) can be used.

  Part or all of the above-described embodiment can be expressed by (Appendix 1) to (Appendix 15) described below, but is not limited to the following description.

(Appendix 1)
A module insertion unit configured to insert a data amount adjustment module configured to adjust a data amount of the message in the data path into a data path, which is constructed in a computer and transmits / receives a message between the process and the driver; ,
An information processing apparatus comprising the information processing apparatus.

(Appendix 2)
The information processing apparatus according to appendix 1, wherein the data amount adjustment module adjusts the data amount of the message flowing through the data path by accumulating the messages until a set data amount is reached.

(Appendix 3)
The data path includes a first module that serves as a call window from the process, a second module that executes processing according to the process, and the driver, and further includes the first module, In the case where each of the second module and the driver further includes a write queue and a read queue,
The data amount adjustment module includes a queue corresponding to the write queue and a queue corresponding to the read queue, and stores the message until a set data amount is reached by each of the corresponding queues. ,
The information processing apparatus according to attachment 2.

(Appendix 4)
The module insertion unit sets the amount of data by setting a high water value and a low water value for each of the queue corresponding to the write queue and the queue corresponding to the read queue, 3. The information processing apparatus according to 3.

(Appendix 5)
The information processing apparatus according to any one of appendices 1 to 4, wherein the module insertion unit inserts a plurality of the data amount adjustment modules into the data path.

(Appendix 6)
Inserting a data amount adjustment module for adjusting a data amount of the message in the data path into a data path, which is constructed in a computer and transmits / receives a message between a process and a driver;
An information processing method comprising:

(Appendix 7)
The information processing method according to appendix 6, wherein the data amount adjustment module adjusts the data amount of the message flowing through the data path by accumulating the messages until the set data amount is reached.

(Appendix 8)
The data path includes a first module that serves as a call window from the process, a second module that executes processing according to the process, and the driver, and further includes the first module, In the case where each of the second module and the driver further includes a write queue and a read queue,
The data amount adjustment module includes a queue corresponding to the write queue and a queue corresponding to the read queue, and stores the message until a set data amount is reached by each of the corresponding queues. ,
The information processing method according to attachment 7.

(Appendix 9)
The module insertion unit sets the data amount by setting a high water value and a low water value of a queue corresponding to the queue for writing and a queue corresponding to the queue for reading, respectively, 9. The information processing method according to 8.

(Appendix 10)
The information processing method according to any one of appendices 6 to 9, wherein in the step, a plurality of the data amount adjustment modules are inserted into the data path.

(Appendix 11)
By computer
Inserting a data amount adjustment module for adjusting a data amount of the message in the data path into a data path, which is constructed in the computer and transmits / receives a message between a process and a driver;
The program to be executed.

(Appendix 12)
The program according to claim 11, wherein the data amount adjustment module adjusts the data amount of the message flowing through the data path by accumulating the messages until a set data amount is reached.

(Appendix 13)
The data path includes a first module that serves as a call window from the process, a second module that executes processing according to the process, and the driver, and further includes the first module, In the case where each of the second module and the driver further includes a write queue and a read queue,
The data amount adjustment module includes a queue corresponding to the write queue and a queue corresponding to the read queue, and stores the message until a set data amount is reached by each of the corresponding queues. ,
The program according to attachment 12.

(Appendix 14)
The module insertion unit sets the data amount by setting a high water value and a low water value of a queue corresponding to the queue for writing and a queue corresponding to the queue for reading, respectively, 13. The program according to 13.

(Appendix 15)
The program according to any one of appendices 11 to 14, wherein, in the step, a plurality of the data amount adjustment modules are inserted into the data path.

  As described above, according to the present invention, the flow control state can be relaxed in the computer in which the STREAMS mechanism is mounted. The present invention is particularly useful for a computer in which UNIX that provides a stream as an OS function is installed.

10 Information processing device 11 Module insertion unit 20 Data path (stream)
21 Stream Head 22 Processing Module 23 Driver 24 Message 30 Operating System (OS)
40 Application Program 41 Process 50 Computer 60 Terminal 110 Computer 111 CPU
112 Main Memory 113 Storage Device 114 Input Interface 115 Display Controller 116 Data Reader / Writer 117 Communication Interface 118 Input Device 119 Display Device 120 Recording Medium 121 Bus

Claims (7)

A module insertion unit configured to insert a data amount adjustment module configured to adjust a data amount of the message in the data path into a data path, which is constructed in a computer and transmits / receives a message between the process and the driver; ,
An information processing apparatus comprising the information processing apparatus.   The information processing apparatus according to claim 1, wherein the data amount adjustment module adjusts the data amount of the message flowing through the data path by accumulating the messages until a set data amount is reached. The data path includes a first module that serves as a call window from the process, a second module that executes processing according to the process, and the driver, and further includes the first module, In the case where each of the second module and the driver further includes a write queue and a read queue,
The data amount adjustment module includes a queue corresponding to the write queue and a queue corresponding to the read queue, and stores the message until a set data amount is reached by each of the corresponding queues. ,
The information processing apparatus according to claim 2.   3. The module insertion unit sets the data amount by setting a high water value and a low water value of a queue corresponding to the write queue and a queue corresponding to the read queue, respectively. Or the information processing apparatus of 3.   The information processing apparatus according to claim 1, wherein the module insertion unit inserts a plurality of the data amount adjustment modules into the data path. Inserting a data amount adjustment module for adjusting a data amount of the message in the data path into a data path, which is constructed in a computer and transmits / receives a message between a process and a driver;
An information processing method comprising: By computer
Inserting a data amount adjustment module for adjusting a data amount of the message in the data path into a data path, which is constructed in the computer and transmits / receives a message between a process and a driver;
The program to be executed.

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