JP5667097B2 - COMMUNICATION DEVICE, COMMUNICATION METHOD, AND COMMUNICATION PROGRAM - Google Patents

Description

  The present invention relates to a communication device, a communication method, and a communication program.

  With recent advances in network technology, there is an increasing demand for real-time communication that transmits messages at high speed on the order of several microseconds to several hundred microseconds. In such communication, since the value of the message itself is lost after a predetermined time, control in message transmission is important.

There is a technique using a message queue in message transmission (Non-Patent Document 1).
FIG. 5 is a diagram showing an outline of message transfer using a queue. Here, a case will be described in which a plurality of messages are transmitted from a transmission source processing program A to a transmission destination processing program via a message queue (buffer).
A set of communication processes included in the processing program A inputs a message to a message queue having a unique identifier. The message queue transfers the messages by buffering the input messages and sequentially outputting the buffered messages to the processing program B. In this technique, when a message has real-time characteristics (that is, when high-speed message transmission is required), the message is transferred even if the message is buffered over a predetermined time T0 to be satisfied. .
The technology described in Non-Patent Document 1 does not perform control or processing according to the real-time nature of the message, and therefore transmits a message that has exceeded the specified time, that is, a message that has no value, and uses communication resources. It will be wasted.

On the other hand, a technique for determining whether or not transmission that satisfies a specified time can be performed before inputting a message to the message queue and inputting only a message that can satisfy the specified time to the message queue has been studied (non-patented). Reference 2).
FIG. 6 is a diagram showing an outline of message transfer described in Non-Patent Document 2. Here, as in the example shown in FIG. 5, a case where a plurality of messages are transmitted from the transmission source processing program A to the transmission destination processing program B via the message queue will be described.
As shown in FIG. 6, in the set of communication processes included in the processing program A, the time required for message transmission (elapsed time + expected processing time) satisfies the specified time before the message is input to the message queue 12. It is determined whether or not. When it is determined that the specified time is satisfied, each communication process inputs a message to the message queue. That is, after determining whether or not the real-time property can be satisfied for each message, the message is input to the message queue.
By performing such processing, it is possible to prevent transmission of a valueless message and suppress waste of communication resources.

Takashi Sakuragawa (translation), Berny M. Goodheart, James H. Cox, “The Architecture of UNIX Kernel Magic System V Release 4”, Pianson Education, April 2000, p. 523-530 Tetsuhiro Nomura, Hiroshi Ishikawa, “Communication Control of Real-Time Packets”, Information Processing Society of Japan Research Report-System Software and Operating System (OS), May 2005, Vol. 2005, no. 79, p. 79-84

  However, in the technique described in Non-Patent Document 2, it is possible to prevent waste of communication resources due to transmission of a valueless message, but time is required for processing for determining whether or not the real-time property can be satisfied for each message. If the time required for this determination process becomes long, it becomes difficult to transmit the message within the specified time. In particular, when the number of messages to be transmitted increases, the time required for determination increases, and as a result, most messages are not input to the message queue, and the message is not transmitted. .

  The present invention has been made to solve the above-mentioned problem, and its purpose is to avoid the transmission of a valueless message while suppressing the influence on the transmission of the message in the transmission of a message having real-time characteristics, A communication method and a communication program are provided.

In order to solve the above problem, the present invention provides a communication device that outputs a message group input from a transmission source to a transmission destination, and has elapsed since the first message was input from the transmission source to the message group. a timer unit for measuring elapsed time, the message set of the message that is input from the transmission source is stored in the buffer, a message of said message groups stored in said buffer in response to a request from the destination When the elapsed time measured by the message input / output unit and the timer unit output to the transmission destination exceeds a predetermined time, the message of the message group stored in the buffer is deleted. A communication device comprising a message discarding unit.

Further, the present invention is the invention of the above SL, the message discarding unit further, each time the timer unit reaches a predetermined time is elapsed time is measured, predetermined corresponding to said time When the output of more than the specified number of messages has not been completed, the messages of the message group stored in the buffer are deleted.

Further, the present invention is the invention of the above SL, the message discarding unit further, deleting the message set of the message stored in the buffer, time out to indicate that there is a message that can not be output within the prescribed time A signal is notified to the transmission source and the transmission destination.

Further, in order to solve the above problem, the present invention provides a communication method performed by a communication device that outputs a message group input from a transmission source to a transmission destination, the first message of the message group from the transmission source. a step but to measure the elapsed time that has elapsed since the input, the message set of the message that is input from the transmission source is stored in the buffer, the stored in the buffer in response to a request from the destination Outputting a message in a message group to the destination, and deleting the message in the message group stored in the buffer when the elapsed time exceeds a predetermined time. A communication method characterized by the above.

In order to solve the above problems, the present invention is the first message of the message group from the source to the computer provided in the communication device for outputting the message group to be inputted from the source to the destination measuring the elapsed time that has elapsed since the input, the message set of the message that is input from the transmission source is stored in the buffer, the message stored in the buffer in response to a request from the destination Outputting a group message to the destination, and deleting the message group message stored in the buffer when the elapsed time exceeds a predetermined time. Communication program.

  According to the present invention, in the communication device, the stored message is deleted when the elapsed time after the message is input from the transmission source exceeds the specified time. As a result, it is possible to avoid the transmission of an insignificant message with a processing with a small calculation load of comparing the elapsed time and the specified time without determining whether the message can be transmitted within the specified time in advance. it can.

It is a schematic block diagram which shows the structure of the communication apparatus 1 in embodiment which concerns on this invention. It is a flowchart which shows the transfer process which the communication apparatus 1 in the embodiment performs. It is a flowchart which shows the transfer time management process which the communication apparatus 1 in the embodiment performs. It is a schematic diagram which shows an example of the message transfer by the communication apparatus 1 in the embodiment. It is a figure which shows the outline | summary of the message transfer using a queue. It is a figure which shows the outline | summary of the other message transfer using a queue.

Hereinafter, a communication device, a communication method, and a communication program according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic block diagram showing the configuration of the communication device 1 in the present embodiment. The communication apparatus 1 receives a message group including at least one message input from a transmission source, temporarily stores the input message group, and outputs a stored message group to a transmission destination. Do. Further, the communication apparatus 1 includes a message input / output unit 11, a message queue 12, and a control unit 13, as shown in FIG.

The message input / output unit 11 outputs a message input from the message transmission source to the message queue 12 and stores the identifier of the transmission source. Further, when accessed from the transmission destination, the message input / output unit 11 stores the identifier of the transmission destination, and reads out the message from the message queue 12 and outputs it to the transmission destination. The message input / output unit 11 receives a registration request signal indicating that it is a message transmission destination from a transmission destination, and also receives a message request signal for requesting a message from the transmission destination. Further, the message input / output unit 11 outputs a timeout signal input from the control unit 13 to the transmission source and the transmission destination.
The message queue 12 stores messages input from the message input / output unit 11. Further, the message queue 12 deletes the message read by the message input / output unit 11 from the stored messages. The message queue 12 is configured as a FIFO buffer, for example.
The control unit 13 controls message transmission based on a predetermined time T0 predetermined for message transmission from the transmission source to the transmission destination. Here, the specified time T0 is a restriction on the time required for the communication apparatus 1 to output a message to the transmission destination after the communication apparatus 1 receives a message from the transmission source in the present embodiment. In other words, it is a condition to be observed in order to maintain the real-time property of the message.

  The control unit 13 includes a timer unit 131, a timeout determination unit 132, and a message discard unit 133. The timer unit 131 measures the time (residence time T1) that has elapsed since the message was input to the communication device 1 from the transmission source. The timeout determination unit 132 determines whether or not the specified time T0 of the message stored in the message queue 12 is kept. Further, the timeout determination unit 132 controls the message discard unit 133 based on the determination result. The message discard unit 133 deletes the message stored in the message queue 12 according to the control of the timeout determination unit 132. Further, when the message discarding unit 133 deletes the message stored in the message queue 12, the message discarding unit 133 notifies the transmission source and destination of the message of a timeout signal indicating the occurrence of timeout through the message input / output unit 11. . Here, timeout means that a message that cannot be transmitted within a specified time occurs.

FIG. 2 is a flowchart showing transfer processing performed by the communication device 1 according to the present embodiment.
In the communication device 1, when the transfer process is started, the timeout determination unit 132 sets a specified time (T0) for transferring the message from the transmission source to the transmission destination, and clears and initializes the message queue 12 ( Step S101). If the specified time is constant regardless of the combination of the transmission source and the transmission destination, the specified time (T0) need not be set.
The message input / output unit 11 waits for an access from the transmission source or the transmission destination (step S102).

When the access is an access from the transmission source (step S103: Yes), the message input / output unit 11 determines whether or not it is the first message in the message group (step S104).
If it is the first message (step S104: Yes), the message input / output unit 11 instructs the control unit 13 to start the transfer time management process (step S105), and the message input from the transmission source is sent to the message queue. 12 is output and stored (step S106), and the process returns to step S102.
On the other hand, when it is not the first message (step S104: No), the message input / output unit 11 determines whether or not a termination signal is input from the transmission source (step S107), and when it is not the termination signal (step S107: No). The process proceeds to step S106, and if it is a termination signal (step S107: Yes), the process returns to step S102. Here, the termination signal is a signal indicating completion of input of a message group from the transmission source.

In step S103, when the access is not an access from the transmission source (step S103: No), the message input / output unit 11 determines whether or not a registration request signal is input from the transmission destination (step S111).
When the registration request signal from the transmission destination is input (step S111: Yes), the message input / output unit 11 stores and registers the transmission destination that has output the registration request signal to the own device (step S112), and performs processing. Is returned to step S102.
On the other hand, when the registration request signal is not input from the transmission destination, that is, when the message request signal is input from the transmission destination (step S111: No), the message input / output unit 11 reads and reads the message from the message queue 12. Output the message to the destination. At this time, the message output to the transmission destination is deleted from the message queue 12 (step S113).

The message input / output unit 11 determines whether or not the transfer for outputting all the messages stored in the message queue 12 to the transmission destination is completed (step S114), and when the transfer is completed (step S114: Yes). Then, the controller 13 is instructed to stop the transfer time management process (step S115), and the transfer process is terminated.
On the other hand, when the message transfer has not been completed (step S114: No), the message input / output unit 11 returns the process to step S102 and repeats the process from step S102 to step S115.

FIG. 3 is a flowchart showing a transfer time management process performed by the communication device 1 according to this embodiment.
In the communication device 1, when the message input / output unit 11 instructs the control unit 13 to start the transfer time management process, the timer unit 131 initializes the count value (T1) to “0” (step S201). .
When the timer unit 131 counts up (increments) the count value (T1) (step S202), the timeout determination unit 132 determines whether or not the count value (T1) matches the checkpoint value (step S203). ).
Here, the check point value is a value indicating at least one time (time period) that is 0 or more and less than the specified time T0. For each checkpoint value, a specified number (M) indicating the number of messages that should be transferred when the elapsed time reaches the checkpoint value is preset. As the check point value, for example, a value such as half of the specified time (T0) (T0 / 2), 1/4 of the specified time (T0), or 3/4 is set.

When the count value (T1) matches the checkpoint value (step S203: Yes), the timeout determination unit 132 outputs the number of messages output to the transmission destination (transfer) after the first message is input from the transmission source. It is determined whether or not the number of completed messages is equal to or greater than a predetermined number (M) (step S204).
If the number of transferred messages is equal to or greater than the specified number (M) (step S204: Yes), the timeout determination unit 132 returns the process to step S202.
On the other hand, when the number of transferred messages is less than the specified number (M) (step S204: No), the timeout determination unit 132 advances the process to step S206.

In step S203, when the count value (T1) does not match the checkpoint value (step S203: No), the timeout determination unit 132 determines whether or not the count value (T1) is greater than the specified time (T0). Determination is made (step S205).
If the count value (T1) is not greater than the specified time (T0) (step S205: No), the timeout determination unit 132 returns the process to step S202.
On the other hand, when the count value (T1) is larger than the specified time (T0) (step S205: Yes), the timeout determination unit 132 controls the message discard unit 133 to start error processing. The message discard unit 133 deletes the message stored in the message queue 12 (step S206).
The message discard unit 133 outputs a timeout signal to the transmission source and transmission destination of the message deleted in step S206 via the message input / output unit 11 (step S207), and ends the transfer time management process. The transmission source and the transmission destination can grasp that the message transfer was not normally performed by the timeout signal.

FIG. 4 is a schematic diagram illustrating an example of message transfer by the communication device 1 according to the present embodiment. Here, a case will be described in which a message group including six messages is input from the transmission source to the communication apparatus 1 and three messages are output from the communication apparatus 1 to the transmission destination within the specified time T0.
As shown in the figure, when a message group including six messages is input, the communication apparatus 1 stores each message in the message queue 12. In response to a request from the transmission destination, the communication device 1 sequentially outputs the messages stored in the message queue 12 to the transmission destination and transfers the messages.
Here, when the specified time (T0) has elapsed since the first message was input from the transmission source, the communication device 1 deletes the message stored in the message queue 12 and transmits the transmission source and Error handling including timeout notification to the destination. Thereby, the communication apparatus 1 can avoid outputting a worthless message to a transmission destination after the lapse of the specified time (T0).

As described above, when the first message is input from the transmission source, the communication device 1 measures the elapsed time (count value) by the timer unit 131, and when the elapsed time reaches the specified time (T0), The message stored in the message queue 12 is discarded, and a timeout notification is sent to the message transmission source and the transmission destination.
Thereby, every time a message is input to the message queue 12, it is possible to avoid transfer of a valueless message without estimating the time required for message transfer.

In addition, the communication device 1 provides a checkpoint, and when the elapsed time reaches the checkpoint and the number of transferred messages has not reached the specified number (M), the specified time even if the processing is continued. It is determined that the message transfer cannot be completed within (T0), and error processing is performed.
Accordingly, the message can be discarded without waiting for the lapse of the specified time (T0), and the processing load on the communication device 1 can be reduced.

  In the above-described embodiment, the transfer process and the transfer time management process have been described as processes performed by the communication apparatus 1. However, processes and threads executed on the computer system perform the transfer process and the transfer time management process. You may make it perform. In this case, the transmission source and the transmission destination are interfaces provided in the computer system, processes and threads executed on the computer system, and the like.

  Note that a program for realizing the function of the communication device according to the present invention is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read by a computer system and executed, whereby transfer processing and Transfer time management processing may be performed. Here, the “computer system” includes an OS and hardware such as peripheral devices. The “computer system” includes a WWW system having a homepage providing environment (or display environment). The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Further, the “computer-readable recording medium” refers to a volatile memory (RAM) in a computer system that becomes a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In addition, those holding programs for a certain period of time are also included.

  The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

DESCRIPTION OF SYMBOLS 1 ... Communication apparatus 11 ... Message input / output part 12 ... Message queue 13 ... Control part 131 ... Timer part 132 ... Timeout determination part 133 ... Message discard part

Claims (5)

A communication device that outputs a message group input from a transmission source to a transmission destination,
A timer unit for measuring an elapsed time since the first message is input from the sender to the message group ;
Wherein said group of messages of a message which is input from the source is stored in the buffer, the message output unit for outputting a message of said message groups stored in said buffer in response to a request from the transmission destination to the transmission destination When,
A message discarding unit for deleting a message of the message group stored in the buffer when the elapsed time measured by the timer unit exceeds a predetermined time set in advance. apparatus. The communication device according to claim 1,
The message discarding unit further includes:
Every time the elapsed time measured by the timer unit reaches a predetermined time, if the output of a predetermined number of messages corresponding to the time has not been completed, the message is stored in the buffer. The communication apparatus, wherein the message of the message group is deleted. The communication device according to claim 1 or 2,
The message discarding unit further includes:
When the message of the message group stored in the buffer is deleted, a time-out signal indicating that there is a message that cannot be output within the specified time is notified to the transmission source and the transmission destination. A communication method performed by a communication device that outputs a message group input from a transmission source to a transmission destination,
Measuring an elapsed time since the first message of the message group was input from the sender;
And outputting the message set of the message that is input from the transmission source is stored in the buffer, a message of said message groups stored in said buffer in response to a request from said destination to said destination,
And a step of deleting a message of the message group stored in the buffer when the elapsed time exceeds a predetermined time. Measuring the elapsed time that has elapsed from the input of the first message of the message group from the source to the computer provided in the communication device for outputting the message group to be inputted from the source to the destination,
And outputting the message set of the message that is input from the transmission source is stored in the buffer, a message of said message groups stored in said buffer in response to a request from said destination to said destination,
And a step of deleting a message of the message group stored in the buffer when the elapsed time exceeds a predetermined time.

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