JP2746207B2 - Emergency buffer reservation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an emergency buffer securing system, and more particularly to an emergency buffer securing system in a communication system driver for performing data communication with a communication partner based on a data communication protocol when buffer resources are exhausted.

[0002]

2. Description of the Related Art A conventional communication system driver is provided with an abnormal situation notification function, and when an abnormal situation such as a failure occurs in a user program on a self-computer system, a communication partner (communication partner) is established. A buffer for exchanging control data (communication source address, communication destination address, protocol type, data length, etc.) based on a data communication protocol with a communication driver on the previous computer system (hereinafter referred to as control data). A buffer is used to notify the communication partner of the occurrence of an abnormal situation using the abnormal situation notification function, and a connection disconnection request is sent by the connection disconnecting means. It was to be cut in the state.

[0003]

In the above-mentioned conventional communication system driver, a control data buffer is used to notify a communication partner of the occurrence of an abnormal situation and to transmit a connection disconnection request. If resources are exhausted and the data transfer buffer and control data buffer cannot be reserved, the communication partner will be notified of the occurrence of an abnormal situation and sending a connection disconnection request. There has been a problem that the occurrence of a situation cannot be notified and the connection cannot be disconnected in a normal state.

SUMMARY OF THE INVENTION In view of the foregoing, it is an object of the present invention to secure an emergency buffer corresponding to a control data buffer on a stack (securing area) of an abnormal event notification function when buffer resources are exhausted. It is an object of the present invention to provide an emergency buffer securing system capable of notifying a partner of occurrence of an abnormal situation and disconnecting a connection in a normal state.

The prior art is disclosed in Japanese Patent Laid-Open No. 4-181.
No. 349 discloses an extension method of a transmission / reception buffer. In this method, an extension buffer is provided so that either a transmission buffer or a reception buffer can be extended in response to a change in the data transfer amount. This is intended to prevent overrun from occurring, and is not intended to notify a communication partner of occurrence of an abnormal situation and disconnection of a connection when buffer resources are exhausted, as in the present invention. .

[0006]

According to a first aspect of the present invention, there is provided an emergency buffer securing system, comprising: a communication driver for performing data communication with a communication partner based on a data communication protocol; And a data transfer request receiving means for receiving a data transfer request after the connection by the connection connecting means, and a data transfer buffer and a control data buffer when the data transfer request is received by the data transfer request receiving means. Buffer securing means;
A data transfer means for transferring data to a communication partner when the data transfer buffer and the control data buffer are secured by the buffer securing means; and a data transfer buffer and a control data buffer secured by the buffer securing means. An abnormal situation notifying function called when not performed, an emergency buffer securing means for securing an emergency buffer corresponding to the control data buffer in the abnormal situation notifying function, and an emergency buffer securing means. Connection disconnection means for notifying a communication partner of a connection disconnection request using the emergency buffer.

[0007]

In the emergency buffer securing system of the present invention, the connection connection means connects a connection with the communication partner, and the data transfer request receiving means receives a data transfer request after the connection connection by the connection connection means.
The buffer securing means secures the data transfer buffer and the control data buffer when the data transfer request is accepted by the data transfer request accepting means, and the data transfer means secures the data transfer buffer and the control data buffer by the buffer securing means. When the data is transferred to the communication partner when the buffer is secured, the abnormal situation notification function is called when the buffer for data transfer and the buffer for control data are not secured by the buffer securing means. The emergency buffer corresponding to the control data buffer is secured in the event notification function, and the connection disconnecting unit notifies the communication partner of the connection disconnection request using the emergency buffer secured by the emergency buffer securing unit.

[0008]

Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a communication driver 10 to which an emergency buffer securing system according to an embodiment of the present invention is applied. This communication driver 10
Connection connection means 1 for connecting a connection with a communication partner (not shown), data transfer request receiving means 2 for receiving a data transfer request from a user program (not shown) of the computer system, and data transfer Securing means 3 for securing a data buffer 6 and a control data buffer 7, a data transfer means 4 for transferring data to a communication partner, and a connection disconnection request using the control data buffer 7 or the emergency buffer 7 '. And an abnormal situation notification function 8 for notifying the communicating party of an abnormal situation when the buffer reservation has failed due to the exhaustion of buffer resources.

The emergency notification function 8 is provided with an emergency buffer securing means 9. The emergency buffer securing means 9 places an emergency buffer corresponding to the control data buffer 7 on the stack of the abnormal situation notification function 8. 7 'is secured.

Referring to FIG. 2, the processing of the communication driver 10 includes a connection connection step S101, a data transfer request receiving step S102, a buffer securing step S103, a data transfer step S104, and an abnormal situation notification function calling step S105. And a connection disconnection step S106.

Next, the operation of the emergency buffer securing system of the present embodiment configured as described above will be described.

When a data transfer request is output from a user program of its own computer system, the communication driver 10 transmits a connection connection request to the communication partner computer system by the connection connection means 1 and attempts to establish a connection. (Step S101).

If the connection of the connection fails because no connection connection response is returned from the computer system of the communication partner, the communication driver 10 immediately returns the control to the user program.

When a connection connection response is returned from the communication partner computer system and the connection is successfully established, the communication driver 10 receives the data transfer request by the data transfer request receiving means 2 (step S10).
2) Attempt to secure the data transfer buffer 6 and the control data buffer 7 by the buffer securing means 3 (step S103).

When the data transfer buffer 6 and the control data buffer 7 can be normally secured, the communication driver 10 uses the secured data transfer buffer 6 and control data buffer 7 to transmit data to the data transfer means 4. Then, data transfer is performed to the communication partner (step S104), and after the data transfer is completed, the connection disconnection unit 5 notifies the communication partner of a connection disconnection request using the control data buffer 7 (step S106). When a connection disconnection response is returned from the communication partner computer system, the communication driver 10 disconnects the connection in a normal state and returns control to the user program of the own computer system.

If the data transfer buffer 6 and the control data buffer 7 cannot be secured due to the exhaustion of the buffer resources in step S103, the communication driver 10
Calls the abnormal situation notification function 8 from the buffer securing means 3 (step S105).

The abnormal situation notifying function 8 has an emergency buffer 7 'corresponding to the control data buffer 7 on its own stack by the emergency buffer securing means 9.
Is set, information (flag, etc.) indicating the occurrence of an abnormal situation such as data transfer suspension is set, and the emergency buffer 7 ′ is delivered to the connection disconnecting means 5.

The communication driver 10 uses the emergency buffer 7 'by the connection disconnecting means 5 to notify the communication partner of the occurrence of an abnormal situation such as the suspension of data transfer and a request for disconnecting the connection (step S106). When a connection disconnection response is returned from the communication partner computer system, the communication driver 10 disconnects the connection in a normal state and returns control to the user program of the own computer system.

[0020]

As described above, according to the present invention, the emergency buffer securing means is provided in the abnormal situation notifying function, and the emergency buffer securing means places the emergency buffer corresponding to the control data buffer on the stack of the abnormal situation notifying function. As a result, it is possible to disconnect the connection in a normal state by notifying the communication partner of the occurrence of an abnormal situation and a connection disconnection request even when the buffer resources are exhausted.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a communication driver to which an emergency buffer securing system according to an embodiment of the present invention is applied.

FIG. 2 is a flowchart showing processing of a communication driver of FIG. 1;

[Explanation of symbols]

 Reference Signs List 1 connection connection means 2 data transfer request receiving means 3 buffer securing means 4 data transfer means 5 connection disconnecting means 6 data transfer buffer 7 control data buffer 7 'emergency buffer 8 emergency notification function 9 emergency buffer securing means 10 communication System driver S101 Connection connection step S102 Data transfer request acceptance step S103 Buffer reservation step S104 Data transfer step S105 Abnormality notification function calling step S106 Connection disconnection step

Claims (1)

(57) [Claims] 1. A communication system driver on a computer.
hand, From a user program running on your computer
Responding to a data transfer request from another
Communication driver and connection on another computer
Connection connection means for connecting After connection connection by the connection connection means
Receiving a data transfer request for receiving the data transfer request.
Attachment means, The data transfer request by the data transfer request receiving means
Transfer from the user program in response to
Data transfer buffer to store requested data
And control data for controlling the data communication.
To secure a buffer for control data for
Steps and The data transfer buffer by the buffer securing unit
In response to the completion of securing the control data buffer and
The data transfer buffer and the control data buffer are used.
To transfer the data to the destination communication system driver
Data transfer means; The buffer reserving means is in front of the data transfer buffer;
If the control data buffer cannot be secured,
Only disconnection request control data that requests disconnection of connection
Emergency buffer with enough capacity to store
And dynamically create a notification to stop data transfer
An abnormal situation notification function means, Receiving the notification from the abnormal situation notification function means,
Creates disconnection request control data and stores it in the emergency buffer
To notify the destination communication system driver
Emergency disconnection buffer
Preservation method.