JPH0758467B2 - Inter-task communication method - Google Patents

Description

TECHNICAL FIELD The present invention relates to an inter-task communication system of an information processing system.

(Prior Art) Conventionally, in this type of inter-task communication method, a semaphore is provided on a file shared between applications, and if the application task that should send information confirms that the semaphore is ready, After the information to be written is written in the shared file, the semaphore on the shared file is made busy. When the application task on the receiving side confirms that the semaphore is busy,
After reading the information from the shared file, the semaphore was canceled.

(Problem to be Solved by the Invention) The above-described conventional inter-task communication method has a drawback that it is not possible to exchange an arbitrary amount of information because there is no means for transmitting the amount of information.

It is an object of the present invention to eliminate the above drawbacks by determining the position of the access point on the file via the operating system to ascertain whether there is information to receive in the file and how much of that information. However, it is to provide an inter-task communication system configured to be able to send and receive an arbitrary amount of information.

(Means for Solving the Problem) The inter-task communication method according to the present invention comprises task management means,
It is configured by including a sharing unit and a processing unit.

The task management means manages the access point in the files accessed by the pair of application tasks, and sets the value of the access point to that of other application tasks in response to a request from one of the pair of application tasks. It is for giving one.

The sharing means is for allowing a pair of application tasks to share the same file and the same access point.

The processing means includes a predetermined position of a file in which information to be transmitted by one of the pair of application tasks to the other of the application tasks is shared by the one of the application tasks and the other of the application tasks. After confirming that the access point is set in the file, write it, move the access point by the amount of written information in the file, and when one of the application tasks confirms the movement of the access point, This is for reading information by the amount of movement of the access point and setting the access point at a predetermined position in the file.

(Example) Next, this invention is demonstrated with reference to drawings.

FIG. 1 is an explanatory diagram showing an embodiment of an intertask communication system according to the present invention. In FIG. 1, 1 is an operating system, 2 and 3 are application tasks, and 4,5 and 5, respectively.
Are files respectively, and 6 and 7 are access points.
The file 4 is written by the application task 2 and read by the application task 3. On the other hand, the file 5 is written by the application task 3 and read by the application task 2. That is, the file 4 and the file 5 are shared between the application tasks 2 and 3.

In the initial state, the access point 6 in the file 4 and the access point 7 in the file 5 are
It is set at the beginning of each file 4,5. These access points 6 and 7 are shared between the application tasks 2 and 3 through the operating system 1, and when the application tasks 2 and 3 are idle, the operating points 6 and 7 are operated by the operating system. Monitoring via 1.

When sending information from the application task 2 to the application task 3, after confirming that the access point 6 is set at the beginning of the file 4 via the operating system 1, the information to be sent is sent to the file 4.
Write to.

By the above operation, the access point 6 moves by the amount of information written in the file 4. When confirming the movement of the access point 6, the application task 3 reads only the movement amount of the access point from the file 4, and then sets the access point 6 at the head of the file 4.

If the same operation is performed using the file 5 and the access point 7, the information is sent from the application task 3 to the application task 2.

The relationship between the above operation and the components of the present invention is summarized as follows.

In the present invention, a task management means, a sharing means, and a processing means are provided.

The task management means manages the access point among the files accessed by the pair of application tasks. Therefore, when a request is sent from the application task, the value of the access point is passed from one application task to another.

The sharing means causes the pair of application tasks to share the same file and the same access point.

The processing means writes information to be transmitted by one of the pair of application tasks to another application task to a file shared by the application task and another application task, and writes the information in the file. When the access point is moved by the amount of information written in step 1 and another one of the application tasks confirms the movement of the access point, the information is read from the file by the amount of movement of the access point and the process of setting the access point at a predetermined position in the file is performed. Let it be done.

(Effects of the Invention) As described above, the present invention confirms whether or not there is information to be received in a file and the amount of the information,
By determining the position of the access point on the file via the operating system, the semaphore and the amount of information sent by the position of the access point in the file can be checked simultaneously by the receiving application task, If it is applied between application tasks that need to transfer a large amount of information frequently, the processing time can be shortened.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an intertask communication system according to the present invention. 1 …… Operating system 2,3 …… Application task 4,5 …… File 6,7 …… Access point

Claims (1)

[Claims] 1. An access point is managed in a file accessed by a pair of application tasks,
Task management means for passing the value of the access point to another one of the pair of application tasks in response to a request from one of the pair of application tasks; Sharing means for sharing the same access point; and information to be transmitted by one of the pair of application tasks to the other of the application tasks, as one of the application tasks and another of the application tasks. After confirming that the access point is set at a predetermined position of the file shared by, write it, move the access point by the written amount of information in the file, and access another one of the application tasks. Confirm the movement of points That when, inter-task communication system, characterized by being configured to include a processing means for performing the processing of setting the access point reads the information by the amount of movement of the access point at a predetermined position of the file from the file.