JP2818521B2 - Task communication method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a inter-task communication how, passing about the task communication how multitasking system for data in particular by a plurality of tasks queued (queue) scheme.

[0002]

BACKGROUND OF THE INVENTION Conventionally, inter-task communication how this type, to indicate the flow of data in FIG. 2, the task A21 by adding the data indicating the communication in queue 23 of the task B22, task B22 Complete sending to. Task B
22 receives the data from the task A21 by extracting the data input by the task A21 from the queue 23.

[0003]

SUMMARY OF THE INVENTION An object of the conventional inter-task communication how described above, if the sending task communicates synchronous that waits for the completion of reception by the receiving task,
Since the transmitting task cannot know the timing when the receiving task takes out the data from the queue, it has a disadvantage that it has to wait for a response indicating that the data sent from the receiving task has been received. Also, once data entered in the queue needs to be canceled immediately after input,
There is a disadvantage that it cannot be easily canceled.

[0004]

SUMMARY OF THE INVENTION An inter-task communication method according to the present invention.
Law, in multiple tasks task communication how multitasking system for transfer of data by queuing method, the sending task adds a transmission advance notice queue prior to transmission of the data, receiving task the transmission advance notice to ensure accept data storage area to add the reception preparation completion notification to the queue, the data stored being informed by the transmission task reception preparation completion notification receiving the reception preparation completion notification When data transmission is completed by adding a transmission data storage notification to the queue after storing the transmission data in the area, and when the transmitting task stops transmitting data after adding the transmission advance notification to the queue. Then, the transmitting task adds a transmission cancellation notification to the queue, and the receiving task that has received the transmission cancellation notification does not receive the transmission advance notification notification received from the transmitting task. Characterized in that it is assumed that Tsu.

[0005]

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

FIG. 1A is a diagram for explaining an embodiment of the present invention, in which a transmitting task waits for reception of transmission data by a receiving task. The embodiment of FIG. 1A has a task 1, a task 2, a queue for inputting task 1, and a queue 4 for inputting task 2, and has a transmission advance notice 101, a reception preparation completion notification 201, and transmission data storage. Three types of data of the notification 102 are used.

[0007] The task 1 is to send the transmission advance notice 101 to the queue 3
And waits for the reception preparation completion notification 201 from the task 2 to be added to the queue 4. The task 1 that has taken out the reception preparation completion notification 201 from the task 2 from the queue 4 stores the transmission data in the area designated by the reception preparation completion notification 201, and adds the transmission data storage notification 102 to the queue 3. . On the other hand, when the task 2 takes out the transmission notice notice 101 from the task 1 from the queue 3, it reserves an area for storing the transmission data, and sends the reception preparation completion notice 201 to which information indicating the area is added, in the queue 4. And waits for transmission data storage notification 102 from task 1 to be added to queue 3.

FIG. 1B is a diagram for explaining one embodiment, showing a case where a transmission task cancels transmission. In this case, in the configuration of FIG.
Is added, the transmission data storage notification 102 is not used, and the reception preparation completion notification 201 is not used or discarded even if used.

[0009] Task 1 sends the transmission advance notice 101 to the queue 3
If you cancel the transmission after adding it to Task 1,
Adds the transmission cancellation notification 103 to the queue 3 without taking out the reception preparation completion notification 201 input to the queue 4. When the task 2 takes out the transmission cancellation notice 103 from the task 1 following the transmission announcement notice 101 from the task 1 from the queue 3, the task 2 discards the transmission announcement notice 101 from the task 1 as if it did not exist. Further, if task 2 adds reception ready completion notification 201 to queue 4 and then removes transmission cancellation notification 103 from task 1 from queue 3, task 2 waits for transmission data storage notification 102. It is assumed that the transmission advance notice 101 from the task 1 is not received. Note that task 1 is sent to queue 3 and sent
01 is added to the queue 4 before the reception preparation notification 20 is added.
It is checked whether 1 exists, and if it exists, it is taken out and discarded in advance.

[0010]

As described above, according to the present invention, a transmission advance notice is input to a queue, a reception preparation completion notification in which a transmission data storage area is designated is received, and transmission data is stored. By eliminating the need for a response from the receiving side and inputting the transmission cancellation notification to the queue in the type of communication, the transmission can be easily canceled even after the transmission advance notice is input to the queue.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining an embodiment of the present invention.

2 is a diagram showing a flow of data of a conventional inter-task communication how.

[Explanation of symbols]

 1, 2, 3, 4 Queue 101 Communication Notice 102 Transmission Data Storage Notification 103 Transmission Cancel Notification 201 Reception Ready Completion Notification

Continuation of the front page (56) References JP-A-4-97436 (JP, A) JP-A-2-208734 (JP, A) JP-A-2-234234 (JP, A) JP-A-59-178049 (JP, A) JP-A-63-157243 (JP, A) JP-A-2-51761 (JP, A) JP-A-63-296533 (JP, A) JP-A-1-216651 (JP, A) 2-249036 (JP, A) JP-A-58-169274 (JP, A) JP-A-2-253448 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G06F 9/46 G06F 13/00 G06F 13/38 G06F 15/163 H04L 11/00 H04L 13/08

Claims (1)

(57) [Claims] 1. A plurality of tasks task communication how multitasking system for transfer of data by queuing method, the sending task adds a transmission advance notice queue prior to transmission of the data, reception Side task
Click adds a reception preparation completion notification to the queue to ensure accept data storage area of the transmission advance notice, the transmission task which has received the reception preparation completion notification was informed by the reception preparation completion notification data After the transmission data is stored in the storage area, the transmission of the data is completed by adding the transmission data storage notification to the queue, and the transmitting task stops the transmission of the data after adding the transmission advance notification to the queue. sometimes,
The transmitting task adds a transmission cancellation notification to a queue, and the receiving task receiving the transmission cancellation notification does not receive the transmission advance notification received from the transmitting task. Law .