JPH0444291B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a data transfer method between programs in a data processing system.

[Conventional technology]

Conventionally, when transferring data between programs, the maximum size of data to be transferred is determined using a predetermined method, and buffers of a size larger than the maximum size are prepared on both the data receiving program side and the data sending program side. This was then done by copying the data in the buffer on the data sending program side to the buffer on the data receiving program side.

[Problem that the invention seeks to solve]

However, with the above-mentioned conventional method, there are problems in that the need to copy data increases the load on the central processing unit and takes a lot of time to transfer data, and the data receiving program also needs to prepare a buffer. Therefore, there were problems in that memory efficiency was poor and a procedure for determining the maximum buffer size was required on the data receiving program side as well.

The present invention has solved these conventional problems, and its purpose is to reduce the load on the central processing unit of a data processing system when transferring data between a data sending program and a data receiving program, and to It is an object of the present invention to provide a method that requires less time for transfer and has excellent memory efficiency.

[Means for solving problems]

A program-to-program data transfer method of the present invention is a program-to-program data transfer method between a data sending program and a data receiving program in a data processing system that can refer to a virtual memory space in segment units. buffer area management means that manages the allocation status of the prepared buffer area and generates a segment descriptor representing the allocated buffer area; buffer allocation requesting means for making a request to an area management means and acquiring a segment descriptor generated by the buffer management means in response to the request; a transfer means for receiving a segment descriptor of a buffer that has undergone transmission processing from the data transmission program that has performed the data processing above, and transferring the received segment descriptor to a data reception program; and a segment description transferred by the transfer means. Receives the segment descriptor of the received buffer from the data receiving program that has processed data on the buffer represented by the child, and requests the buffer area management means to release the buffer represented by the segment descriptor. and buffer release request means.

[Effect]

When transferring data from a data sending program to a data receiving program, a buffer of the size required for data transfer by the data sending program is allocated from a buffer area prepared in advance, and a segment descriptor representing this allocated buffer is written as a buffer area. Generated by area management means. After the data sending program processes data on the buffer represented by this generated segment descriptor, it notifies the data receiving program of the segment descriptor using the transfer means, and the data receiving program that receives this notification is not notified. After processing the buffer data expressed by the segment descriptor, the buffer release request means requests the buffer area management means to release the buffer expressed by the segment descriptor.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention, in which the present invention is applied to a data processing system capable of referencing virtual memory space in units of segments.

The inter-program data transfer method of this embodiment is as follows:
As shown in the figure, buffer allocation requesting means 1;
It is composed of a buffer release requesting means 2, a buffer area 3 allocated to a part of the virtual memory space, a buffer area management means 4, a transfer means 5, a data transmission program 6, and a data reception program 7.

Upon receiving a request from the buffer allocation requesting means 1, the buffer area management means 4 performs processing to cut out a buffer of a size commensurate with the requested size from the buffer area 3, generate a segment descriptor representing the buffer, and If assigned,
For example, the buffer part is updated on the internal management table while it is in use, and the buffer release request means 2
When a request is received from the buffer area, the buffer area is managed by updating the contents of the management table corresponding to the buffer of the requested segment descriptor to unused, for example. Note that as the segment descriptor, for example, a descriptor consisting of a base address and a size can be adopted.

The buffer allocation requesting means 1 performs a process of requesting the buffer area management means 4 to cut out a buffer of the size requested by the data transmission program 6 from the buffer area 3, and a segment descriptor generated by the buffer area management means 4. A process is performed to notify the data transmission program 6 of the request source.

Upon receiving a request from a data transmission program 6 that has performed data processing on the buffer represented by the segment descriptor obtained by the buffer allocation requesting means 1, the transfer means 5 transmits the segment descriptor of the buffer that has been transmitted. It receives the data and transfers it to the data receiving program 7.

When receiving a request from the data receiving program 7 that has performed data processing on the buffer represented by the segment descriptor transferred by the transfer means 5, the buffer release requesting means 2 releases the segment descriptor of the buffer that has undergone reception processing. It receives the data from the data receiving program 7 and performs processing to request the buffer area management means 4 to release the buffer represented by the segment descriptor.

Next, the operation when transferring data between programs will be explained with reference to FIG.

Data transmission is performed as follows. That is, when data to be transferred is generated, the data transmission program 6 first determines the buffer size necessary for data transfer, and issues a request to the buffer allocation requesting means 1. When receiving this request, the buffer allocation requesting means 1 requests the buffer area management means 4 to cut out a buffer of a size commensurate with the size requested by the data transmission program 6 from the buffer area 3 and notify the segment descriptor thereof. do. In response to this, the buffer area management means 4 first refers to the contents of the management table, cuts out a buffer of a size commensurate with the requested size from the unused portion, for example, the buffer 31 in FIG. After registering the status in the management table, a segment descriptor representing the buffer 31 is generated and notified to the buffer allocation requesting means 1.

When the buffer allocation requesting means 1 is notified of the segment descriptor from the buffer area management means 4,
This is notified to the data transmission program 6. When the data transmission program 6 receives this notification, it processes the data on the buffer 31 represented by the segment descriptor, and upon completion of this processing, passes the segment descriptor to the transfer means 5.

When the transfer means 5 receives the segment descriptor from the data transmission program 6, it notifies the data reception program 7 of this.

When the data reception program 7 receives a segment descriptor from the transfer means 5, it processes the data on the buffer 31 represented by the segment descriptor, and when the processing is completed, it sends the segment descriptor to the buffer release request means 2. hand over.

When the buffer release requesting means 2 receives a segment descriptor from the data receiving program, it requests the buffer area management means 4 to release the buffer 31 corresponding to the segment descriptor.

When the buffer area management means 4 receives a request from the buffer release requesting means 2, the buffer area management means 4 stores the contents of the management table in the buffer area 31 expressed by the segment descriptor.
Update the buffer so that it is unused and execute buffer release processing.

In the above embodiments, data transfer between one data transmission program 6 and one data reception program 7 was taken as an example, but the present invention also applies to data transfer between a plurality of data transmission programs and a plurality of data reception programs. is applicable. In that case,
Buffer allocation requesting means 1 is connected to a plurality of data transmission programs, and buffer release requesting means 2
is connected to a plurality of data reception programs, and the transfer means 5 is connected to a plurality of data transmission programs and data reception programs. In addition, the data transmission program passes the segment descriptor and the purpose of use of the buffer expressed by the segment descriptor to the transfer means, and the transfer means places the segment descriptor in a different queue for each purpose of use and receives the data. A configuration is adopted in which a segment descriptor matching the purpose of use requested by the program is taken out from a queue and passed to the data receiving program.

〔Effect of the invention〕

As explained above, according to the present invention, the buffer area management means, the buffer allocation request means,
Since the transfer means and the buffer release request means are provided, the following effects can be obtained.

Since there is no need to copy data as in the past, the load on the central processing unit can be reduced.

Since there is no need to copy data, the time required for data transfer can be shortened.

Since there is no need to prepare a buffer on the data receiving program side, memory efficiency is improved.

Since there is no need to prepare a buffer on the data receiving program side, the procedure for determining the maximum buffer size can be omitted.

The buffer allocated for data transfer between the data sending program and the data receiving program is released upon request by the buffer release request means when the data receiving program completes data processing, and the released buffer is used for other data sending. It can be used for data transfer by programs, etc., and the limited buffer area can be shared by many data sending programs and data receiving programs. Efficiency is further improved.

By using a segment descriptor that expresses the buffer in which the data is stored in order to specify the data to be transmitted, the segment descriptor that receives the data receiving program can immediately recognize the location of the data to be transmitted. Can be accessed.

[Brief explanation of drawings]

FIG. 1 is a block diagram of one embodiment of the present invention. In the figure, 1 is a buffer allocation requesting means; 2 is a buffer allocation requesting means;
is a buffer release requesting means, 3 is a buffer area, and 4 is a buffer release request means.
5 is a buffer area management means, 5 is a transfer means, 6 is a data transmission program, and 7 is a data reception program.

Claims (1)

[Scope of Claims] 1. In an inter-program data transfer method between a data sending program and a data receiving program in a data processing system capable of referencing a virtual memory space in units of segments, there is provided the following: Buffer area management means for managing the allocation status of buffer areas and generating segment descriptors representing the allocated buffers; and buffer area management means for allocating from the buffer area a buffer of a size requested by the data transmission program. buffer allocation requesting means for requesting a segment descriptor generated by the buffer management means in response to the request; a transfer means that receives a segment descriptor of a buffer that has been sent from a data sending program that has processed the data, and transfers the received segment descriptor to a data receiving program; and a segment descriptor transferred by the transfer means. A buffer release request that receives a segment descriptor of a buffer that has undergone reception processing from a data receiving program that has processed data on a buffer that is being processed, and requests the buffer area management means to release the buffer represented by the segment descriptor. An inter-program data transfer method characterized by comprising: means.