JPH0365731A - Task state management system - Google Patents

Abstract

PURPOSE:To improve executing speed by managing the state change of each service task to execute the service of each icon by a picture managing task, and informing each service task of the task number of the task whose state was changed by the picture managing task. CONSTITUTION:An input/output managing means 6 processes an input signal from a pointing device 3, and executes the calculation of the coordinate position of a display 2 pointed by the pointing device 3, and informs a service task group 5 of its coordinate information, and simultaneously, it manages an icon group 4 displayed on the display 2. A task state change informing means 7 decides the presence of the change of the state of the service task, and if it was changed, it informs a task state managing means 8 of this purport, and the task state managing means 8 manages the change of the state informed from each task of the service task group 5, and informs the service task group 5 the state of what task was changed. Thus, the exchange of a message between the respective service tasks is eliminated, and processing speed can be improved.

Description

[Detailed Description of the Invention] [Summary] This invention relates to a method in which a plurality of tasks corresponding to a plurality of icons displayed on a display execute the service of each icon while exchanging the status of each task through messages. A task is provided to manage state changes, and the service task whose state has changed self-reports the state change to its management task, while the management task collectively informs each service task of which service task's state has changed. The purpose is to eliminate message exchange between each service task and improve processing speed by sending messages to the
A pointing device at a workstation where a task corresponding to the icon in a service task group executes a service while exchanging messages between tasks according to an icon selected by the pointing device from a group of icons on the display. an input/output management means for sending a message to the service task group of the coordinate information input by the service task group, and further managing the display of the icon group on the display according to the message from the service task group; and a message from the input/output management stage f. A task state change notification means notifies that the task accessed by transmission changes its state due to the access, and the change of state notified by the task state change notification means is sent to a service task group as necessary. and task status management means for sending messages to each task.

[Industrial Application Field] The present invention relates to a task state management method, and more specifically, the present invention relates to a task state management method, and more specifically, a plurality of tasks corresponding to a plurality of icons displayed on a display exchange the states of each task through messages. Concerning the method of executing the service.

[Conventional technology]

BACKGROUND OF THE INVENTION With the advancement of computer technology, efforts are being made to make computers easier to use, that is, to improve the man-machine interface. One of these is the combination of an icon and a pointing device.

Reduce command input from the keyboard as much as possible,
By pointing at an icon displayed on a display with a pointing device such as a mouse, electronic pen, or touch panel, a command service corresponding to the icon is executed. Since icons corresponding to commands that can be executed at that time are displayed on the computer's display, it is easy to understand and operate even for beginners.

FIG. 5 is an explanatory diagram of the operation of a computer service using icons.

There are seven icons on the display in Figure (a-1): document 4-1, clock 4-2, memo 4-3.
, Telephone 4-4, Trash can 4-5, Drawer 4-6, Postal code 4-
7 is displayed. D4-7 serves as a cursor,
By moving the hand 4-7 using the pointing device to point to other icons, the service corresponding to each icon is executed.

For example, by pointing to a document 4-1 with a hand (cursor) 4-7 as shown in FIG. 4(a-1), services related to the document such as creating, updating, registering, and deleting the document can be performed. Further, when pointing to the trash can 4-5, services such as discarding documents and the like into the trash can and showing the contents of the trash can are executed. When pointing to the drawer 4-6, services for storing created documents in the storage area and retrieving stored documents become executable. In addition, pointing to the clock 4-2 will display the time, pointing to the memo 4-3 will secure a place to write a memo, and pointing to the telephone 4-4 will search for a phone number or perform an auto-dial service. be done.

Now, if the document 41 is accessed by pointing the cursor as shown in FIG.

Then, as shown in the same figure (a-2), the trash can 4-5
By accessing , a service for discarding the previously accessed document 4-1 in the trash can is executed.

And when this service is executed, document 4-
1 is moved to the trash can, and the icon of the document 4-1 is deleted from the display 2 as shown in FIG. 4(a-3).

On the other hand, in the state shown in Figure (a-1), if the trash can 4-7 is accessed as shown in Figure (b-1) without accessing document 4-1, ) runs a service that displays the contents of the recycle bin on the display. In the figure, Document 1 and Document 2 which have been thrown away in the trash can are displayed.

Here, in the case of (a-1 to a-3) in the same figure, the recycle bin service
-1, and executes a service that throws the document into the trash can. On the contrary,
In the case of (b-1, 2) in the same figure, the trash can service is
Before accessing the trash can 4-5, it is determined that no icon has been accessed, and a service for displaying the contents of the trash can is executed.

Services corresponding to each icon, such as this trash can service, are executed by tasks corresponding to the respective icons.

FIG. 6 is an explanatory diagram of the conventional system of operations of tasks (service tasks) corresponding to the services of each icon.

The service for the document icon 4-1 is executed by the document service task 5-1, the service for the trash can 4-5 is executed by the trash can service task 5-5, and for other icons as well, icon 4-i is executed by the document service task 5-1. Service task 5-i executes the service.

The service tasks corresponding to each icon are placed on an equal footing, and above them are the screen management task 9 and the input management task 10. The input management task IO calculates the positional coordinates on the display accessed using a pointing device such as a mouse, an electronic pen, or a touch panel, and sends a message 11 using the coordinates as an argument to the screen management task 9. On the other hand, the screen management task 9 manages the numbers of all tasks displayed on the display 2, and the message 1 sent from the input management task 10
Message 12 with the coordinate information of 1 as an argument is sent to all tasks being managed.

Now, suppose that the user accesses the document icon 4-1 with the hand icon 4-7 (FIG. 6(a)). Then, the input management task 10 sends a message 11 with the coordinate information of the hand 4-7 as an argument to the screen management task 9, and the screen management task 9 also sends a message to each service task (5-■, 5-2) that it manages. ,... 5-6) sends a message 12 with the coordinate information of the hand 4-7 as an argument.

Next, each service task (5-1, 5-2,... 5-
6) receives the message 12 from the screen management task 9, analyzes the message, and determines whether the coordinate information as an argument is included in the range in which the icon corresponding to each service task is displayed. . Now, since the coordinates of 4-7 are within the range of the document icon 4-1, the document service task 5-1 determines that its own icon 4-1 has been accessed. Further, the other service tasks (5-2, 5-3, . . . , 5-6) determine that the person who has been accessed is not themselves and end the processing.

Since the document service task 5-1 is expected to perform some kind of processing next as a result of the access, it changes its state and enters a waiting state for the next processing. On the display 2, this change in status is displayed, for example, by inverting the color of the document icon 4-1.

Next, it is assumed that the user accesses the trash can icon 4-5 using the hand icon 4-7 (FIG. 3).

In response to this access, the input management task 10 sends the message 13 with the coordinate information as an argument to the screen management task 9 as described above, and the screen management task 9 , . . . , 5-6), the message 14 with the coordinate information as an argument is transmitted. Each service task analyzes its message 14 and determines whether it is itself being accessed. In this case, since Recycle Bin 4-5 is pointed to, Recycle Bin Service Task 5
-5 determines that it has been accessed, and other service tasks have not been accessed, so the process ends.

The services provided by Trash Can Service Task 5-5 include:
The process of discarding documents etc. in the trash (i.e.
There is a process in which the trash can service task manages discarded documents, etc.) and a process in which documents, etc. that have been discarded in the trash can (that is, managed by the trash can service task) are presented. Which of these services is requested is determined based on whether or not there is a document, etc. that is about to be discarded at that time.

That is, the trash can service task 5-1 determines whether or not the task is waiting to be discarded (i.e., whether the task is changing its state) for all service tasks that may be discarded. Send inquiry message 15.

Document service task 5-1 is this message 1
5, a reply message 16 indicating that the task is in a standby state for the next process is returned to the trash can service task 5-5. Trash can service task 5-5 is reply message 16
It is determined that the document service task 5-1 is waiting to be discarded by
1 under the trash box service task 5-5). By executing this process, the document service task 5-5 is erased from the display 2 (FIG. 5(a-3)).

On the other hand, in response to the message 15 sent by the trash can service task 5-5 inquiring whether the status has changed, a reply message 1 indicating that the status has changed is sent.
If 6 is not returned from any service task,
The trash can service task 5-5 determines that the current access is a request for a service that presents the contents of the trash can, and presents documents and the like managed by the trash can service task (FIG. 5 (b-2)).

FIG. 7 shows screen management task 9 ((a) in the same figure), document service task 5-■ ((b) in the same figure), and trash service task 5-5 ((C) in the same figure) as examples. It is an operation flowchart of a service task.

When the screen management task 9 (FIG. 7(a)) starts processing (Start), it first waits for messages from other tasks (371). When a message is received, the message is analyzed (S72).

Then, each process is executed depending on the type of message. Assuming that the received message is a message (11, 13) whose argument is the coordinate display from the input management task 10 (S73), the screen management task 9 manages the number of the service task corresponding to the icon. , each service task (5-1, 5-2,..., 5-6
), send a message (12, 14) with the coordinate information received from the input management task IO as an argument.37
4), then returns to the state of waiting for message reception again (
S71).

Further, the document service task 5-1 is also normally in a state of waiting to receive a message (S75 in FIG. 7). When a message is received, the content of the message is analyzed (376) in the same way as the screen management task, and processing corresponding to the type of message is executed.

If the message is the access coordinate notification 14 from the screen management task 9 (377), it is determined whether the coordinates are within the display range of the document icon 4-1 (
37B). If it is within the display range of the icon 4-1, it is determined that the document service task 5-1 has been accessed)79).

The value of a flag (FLAG) indicating the access state of the task is set to 1 (S80). This flag is a state change value storage unit that takes a value of 1 when a task is accessed and its state changes, and takes a value of 0 when it is not accessed. On the other hand, the coordinate information of the received message is the document icon 4
If it is outside the range of -1, it is assumed that another task has been accessed (581), and the value of the flag is set to O (S82).
).

After determining the value of the flag (S80 or 582), the process returns to the state of waiting for reception of the next message (S75).

If the received message is a message confirming the status of the task (for example, status confirmation message 15 from the trash can service task) (S83), it is determined whether the flag is 1 (i.e., whether the status of the task has changed or not). 584) If FLAG=1 (Y), send message 16 with its own task number as an argument to notify the task that sent the status confirmation message that the status has changed. (S85). FLAG=
If it is 0 (N), notify that the state is unchanged, for example by sending a message with argument -1 (
S86). After that, the state returns to waiting for message reception (
S75).

As explained above, each service task is normally in the state of waiting to receive a message, and when a message is received, it analyzes the message and executes the processing appropriate for the type of message. .

The same applies to the trash can service task 5-5. First, in a message reception waiting state (SST), when a message is received, the message is analyzed (38B) and processing appropriate to the content of the message is executed. Message screen management task 9
If the coordinate notification is from (S89), then the area of the coordinates is determined, and it is determined whether the trash can service task or another service task has been accessed (S89). If the coordinates are within the display range of the trash can icon 4-5, it is determined that the trash can service task 5-5 has been accessed (590), and in order to determine which of the two services related to the trash can to be executed, It sends the status change confirmation message 15 to other service tasks whose status can change (591), and waits for reception of the next message (S87). On the other hand, if it is determined as a result of the area determination (S89) that the access is not to the trash can service task (S92), no processing is performed and the process returns to the state of waiting for reception of the next message (S87).

If the received message is a reply to the status change confirmation message sent by the trash can service task 51 (S93)
, the trash service task analyzes the message and determines whether the state has changed (394). In other words, the argument of the received message is the task number (positive integer)
If so, it is determined that the state of the service task with that task number has changed (Y), and the process of discarding the service task with that task number into the trash can is executed (395). On the other hand, if the argument of the received message is -1 (negative number), it is determined that the status has not changed, and a process is executed to display the contents (documents, etc.) that have already been discarded in the trash can (396). After completing the processing in S95 or 396, the process returns to the state of waiting for reception of the next message (387).

As described above, in the conventional method, if a service task requires status information of another service task when executing it, it sends a message asking the other service task about its status, and the response message is sent to the other service task. A method is adopted in which processing is performed according to the content.

[Problem to be solved by the invention]

However, in the above-described method, each time the status of another service task is required, it is necessary to send a message inquiring about the status, receive a reply message, judge the reply, and execute the service. Furthermore, if there are many service tasks whose status can change, it is necessary to send a message inquiring about the status to all of these service tasks, and to judge and process the content of each reply message. For this reason, there is a problem in that it takes time to send and receive return messages, reducing service execution speed and processing efficiency.

This means that even if the state of a service task changes, the state change is managed only within that service task, and the state change is only notified to other service tasks when the state is questioned by a message from another service task. This is because the system uses a method of communicating the following.

The present invention provides a task that manages changes in the state of all service tasks, and a service task whose state has changed self-reports the state change to its management task, while the management task reports which service task's state has changed. The purpose of this invention is to eliminate message exchange between each service task and improve processing speed by sending a message to each service task all at once.

[Means to solve the problem]

FIG. 1 is a functional block diagram of the present invention. The present invention
Display multiple icons (icon group 4) on the display 2, select an icon using the pointing device 3, and access the task corresponding to that icon (service task group 5) to respond to each icon. The workstation 1 is assumed to be provided with the following services.

The input/output management stage 6 processes the input signal from the pointing device 3 and calculates the coordinate position of the display 2 pointed by the pointing device 3.
It notifies the service task group 5 of the coordinate information and also manages the icon group 4 displayed on the display 2.

The task state change notification means 7 determines whether or not there is a change in the state of the service task, and if there is a change, it notifies the task state management stage 1 8, which will be described later, to that effect.

The task state management means 8 manages changes in states notified from each task of the service task group 5, and notifies the service task group 5 of which task's state has changed.

[For production]

The user selects the icon group 4 (
Icon 1..., Icon Mi 1..., Icon n
), use the pointing device 3 to select an icon (icon i) that provides the desired service. Then, the pointing device 3 inputs the position information of the cursor selected by the user to the input/output management lower stage 6. The input/output management means 6 calculates the coordinates of the cursor based on this input, and notifies each task (task 1, task 2, . . . , task n) of the service task group 5 of the coordinate information.

Each task determines whether or not its own task has been selected from the coordinate information input from the input/output management means 6. That is, when the user selects icon i and the input/output management lower stage 6 notifies the service task group 5 of its coordinate information,
Service task i corresponding to icon i determines that it has been selected from the coordinate information.

If the accessed service task i is a task whose state changes due to the access, the task state change notification means 7 provided in the task notifies the task state management means 8 of the change in state.

The task state management stage 1 8 receives the state change notification from the task i in the service task group 5 whose state can be changed, and manages the number of the task whose state has changed, and also manages the number of the task whose state has changed, and also manages the number of the task whose state has changed. Task 2, ..., task n
) is notified of the task number of the task whose state has changed.

By notifying this task number, service tasks that require state change information of other service tasks can know the task number of the task whose state has changed, and can execute the service based on that information. Become. For example, in the case of the trash can service task explained in the conventional method section, when the trash can service task receives a status change notification of the document service task from the task status management means 8, it executes the process of discarding the document service task in the trash can. , If there is no status change notification, execute the process of presenting the contents of the trash can.

〔Example〕

Examples will be described below with reference to FIGS. 2 to 4.

FIG. 2 is a system configuration diagram of an embodiment of the present invention.

This embodiment can be configured as a personal computer system or a workstation system, for example.

A main memory 22, a secondary storage device 23 such as a floppy disk device, a hard disk drive, or a magnetic tape device, a display controller 24, and a touch panel control device 25 are connected to the CPU 21. The display controller 24 is connected to a display 27 via a display memory buffer 26, and the touch panel control section 25 is connected to a touch panel 28. However, the touch panel 28 can be replaced with other pointing devices, such as a mouse or an electronic pen.

In addition to the operating system, the main memory 22 includes service task processing programs corresponding to each icon, management programs for input/output devices such as displays and touch panels (execution programs for the input/output management means 6), and task state management 1. An execution program for stage 8, etc. is stored, and the CPU 21 executes processing according to this program. It is desirable that the operating system be capable of executing multiple tasks in parallel.

Next, the operation of this system will be explained.

The user selects one of the icons displayed on the display 27 using the touch panel 28.

Then, the touch panel control unit 25 inputs the position on the display touched by the user to the CPU 21.

The CPU 21 executes the input/output processing program in the main memory 22 and calculates the coordinates of the position on the display touched by the user. Then, the coordinate information of the calculation result is sent as a message to the service task corresponding to each icon.

Each service task receives a message and executes processing according to its own program.

Each task first determines whether the coordinate information included in the received message is included in the display area of its own task's icon, and if not included, the process ends.

If the task is included in the display area of its own icon, it is determined that the task has been accessed, and the processing according to the processing program of the accessed task is then executed.

For example, if the accessed service task is a document service task that provides document creation, updating, registration, deletion, etc., this access declares that some kind of processing will be performed on that document. Become. That is, the document service task changes state due to this access and waits for the user's next request.

A service task, such as a document service task, which changes its state in response to user access, then sends a message to the execution program of the task state management stage 1 8 that the state has changed.

The task state management means 8 manages the task number of the service task whose state has changed. Then, when the user makes the next request (that is, selects an icon), the input/output management stage 1 6 notifies the coordinate information to all service tasks, and the current state changes. Sends a message with the task number of the service task being executed.

Each service task receives a message from the task state management means 8 and determines whether or not its own task has been accessed, and the accessed service task is processed according to its own program and the task number of the service task whose state has changed. Execute. For example, if the trash can service task is accessed next to the previous document service task, the task status management means 8 notifies the trash can service task of the task number of the document service task. Browse and execute the process to throw this document service task into the trash.

FIG. 3 is an explanatory diagram of the flow of messages between each task in one embodiment.

As in the case of the conventional method, the input management task 31, the screen management task 32, and each icon (4-1, . . . , 4
-6) corresponding service tasks (document service task 33-1, clock service task 33-2,...
, a trash can service task 33-5, and a withdrawal service task 33-6). The input management task 31 plays the role of calculating the coordinates on the display pointed by the user based on cursor information input from a pointing device such as a touch panel or mouse, and transmitting the coordinates as a message to the screen management task 32. . Further, the screen management task 32 manages the task number of the service task corresponding to the icon displayed on the display 2, as well as the task number of the task whose state has changed. It has the role of sending a message to all service tasks using the coordinate information sent from the input management task 31 and the task number of the task whose status is changing as arguments.

Here, if the state of any service task has not changed (initial state), the value of the task number is set to -1.

Now, assume that the user accesses the document icon 4-1 by pointing at the hand icon 4-7 (see figure (a)
)). Then, the input management task 31 first calculates the coordinates of the icon 4-7 of 〒, and sends a message 34 using the coordinate information as an argument to the screen management task 32. Upon receiving this message 34, the screen management task 33 sends a message 3 to all the service tasks it manages, with coordinate information and the task number of the task whose status has changed as arguments.
Send 5. At this point, there is no service task whose state is changing, so the task number argument is -1.

Each service task receives the message 35 and determines whether or not it has been accessed. That is, an area determination is performed to determine whether or not the coordinate information included in the message 35 is included in the display range of the icon corresponding to the own service task. If it is within the range of the icon, it is determined that the service task has been accessed. If the coordinate information is outside the range of the icon, it is determined that it has not been accessed, and the service task ends the process.

In the case of Figure 3(a), document service task 3
3-1 determines that its own task has been accessed. Since the other service tasks (33-2, . . . , 33-6) have not been accessed, the process ends. The document service task 33''-1 changes its state due to this access.Then, it sends a message 36 to the screen management task 32 to notify that the state has changed.The argument of this message is the task number of the document service task.Screen management The task 32 holds the task number of the document service task whose status has changed in response to this message 36.This allows the user to select the document icon 4-1.
The processing caused by accessing ends.

Next, it is assumed that the user accesses the trash can icon 4-5 by pointing with the hand icon 4-7 (in the same figure).

The human power management task 31 calculates the coordinates on the display that the hand icon 4-7 points to, as in the case described above, and sends the message 37 with the coordinate information as an argument to the screen management task 3.
Send to 2. The screen management task 32 receives the message 37 from the input management task 31 and sends the coordinate information sent from the all input management task 31 and the task whose status has changed to all the service tasks it manages. A message 38 is sent with a number (ie, the task number of the document service task) as an argument.

Each service task (33-1, ..., 33-6) is
Upon receiving the message 38, as described above, the area is first determined based on the coordinate information included in the message, and it is determined whether or not the own service task is being accessed. In this case, trash service task 33-5 was accessed. Other service tasks (33-1, ..., 33-
4.33-6) has not been accessed, so the process ends.

The trash can service task 33-5 determines that its own task has been accessed, and since the task number whose status has changed (i.e., the task number of the 6 document service task) has been sent, the service task (
The process is executed by executing the process of discarding the document service task 33-1) in the trash can. That is, the task number of the document service task 33-1 is registered in the area for managing the task numbers of tasks thrown away in the trash can.

Then, the processing of the trash can service task 33-5 ends.

In this way, the screen management task 32 manages the task number of the service task whose status has changed, and also manages the task number of the service task whose status has changed.
2 adds the task number of the task whose state has changed to the argument of the message sent by 2, and when the state of the service task changes, the service task itself notifies the screen management task 32 that the state has changed. ,
It becomes possible to execute a service without exchanging messages between service tasks to confirm changes in status, which was done in the conventional method.

FIG. 4 shows an input management task 31, a screen management task 32,
3 is an operation flowchart of service tasks taking the document service task 33-■ and the trash can service task 33-5 as examples.

First, the input management task is in a state (S41) in which the input management task normally waits for an interrupt caused by the user clicking the pointing device. When the user moves and clicks on the input button, an interrupt occurs.In response to this interrupt, the input management task 31 acquires information regarding the coordinates specified by the user from the control device of the pointing device, and calculates the specified coordinates (S42). , then sends a message (34, 37) with the coordinate information as an argument to the screen management task 33 (S43). This completes the processing of the input management task 31, and waits for the next user input interrupt to occur. The process returns to the standby state (S41).

Next, the operation of the screen management task 32 will be explained along the lines shown in FIG. First, when a task enters a running state, it enters a state in which it waits to receive messages from other tasks (344). When a message is received, the content of the message is analyzed (545) and processing appropriate to the message content is executed.

If the message is a message of coordinate information notified from the human management task 31 (S46), a message ( 35, 38
) to each service task (347).

The content of the message is a service task (33-1,...
, 33-6) in the case of status change notification 36 (348)
Then, the screen management task 32 stores the task number of the service task whose state has changed in the memory (S49). 34
7. After executing the process of S49, the process returns to the message reception waiting state (S44).

As described above, the screen management task 32 manages the task number of the state change task, adds the task number of the service task whose state is changing at that time as an argument of the message to be sent, and sends it along with the coordinate information. ,
The service task receiving this message can execute the service without exchanging status confirmation messages between the individual service tasks.

On the other hand, as an example of the operation of a service task that executes the service of each icon, FIG. (C),
Further, the operation of the trash can service task 33-5, which performs services based on information of other tasks whose states change, will be explained along with FIG. 3(d).

When the document service task 33-1 enters the execution state, it first waits to receive messages from other tasks (
S50). When a message is received, its contents are analyzed (551) and processing appropriate to the contents is executed.

If the message is a notification of the designated coordinates and status change task number sent by the screen management task 32 (352), then whether or not the user has accessed the document service task is determined by determining the area of the designated coordinates. (S53), if the designated coordinates sent from the screen management task 32 are within the display area of the document icon 4-1, it is determined that the document service task has been accessed (554); If the coordinates are not within the display area, it is determined that the document service task is not accessed and that another service task is accessed (S55).

If the document service task is accessed (
S54), since the status of the document service task changes, send a message to the screen management task 32 to the effect of the change as a message 36 with the task number as an argument 556);
After that, it enters the waiting state for receiving the next message (S50).
. On the other hand, if the access is not a document service task (355), the process returns directly to the message reception waiting state (S50).

Next, when the trash can service task 33-5 (FIG. 4(d)), which receives information from the state change task and performs processing, enters the execution state, it handles messages sent by other tasks in the same way as other tasks. It enters a reception waiting state (S57). When a message is received, the content of the message is analyzed and processing appropriate to the content is executed (358).

Here, the message is a notification message (38) of the designated coordinates and state change task number from the screen management task 32.
In this case (S59), similarly to the operations of other service tasks, first, area determination is performed to determine whether or not the own service task has been accessed (360). The coordinate information in the message is used to determine the area, and if the coordinates are within the display area of the trash can service task icon 4-5, it is determined that the access has been made (361). If the trash service task was not accessed (S62),
The process returns to the state of waiting for reception of the next message (S57).

If it is determined that the trash can service task has been accessed (S61), then it is determined whether there is a task whose status has changed (S63). This process is performed by referring to the status change task number of the message from the screen management task 32. If this task number is a positive integer, the state of the service task with this task number has changed (S64)
This means that if the task number is -1, there is no service task whose state is changing (S65).
It means that.

In the case of 364, a process of discarding the service task with the task number in the trash can, that is, a process of registering the task number in the task number storage area managed by the trash can service task is executed (366).

On the other hand, in the case of S65, processing is executed to display the contents of the trash can, that is, the number of the abandoned task managed by the trash can service task (S67).

After completing the processing of 366 and S67, the process returns to waiting for reception of the next message (S57).

By having each task process according to the above flowchart, it becomes possible to execute the service without exchanging messages for status change confirmation between the service tasks.

〔Effect of the invention〕

The present invention allows a screen management task to manage changes in the state of each service task that executes the service of each icon, and the screen management task notifies each service task of the task number of the task whose state has changed. To make it possible to eliminate the need for exchanging status change confirmation messages.

As a result, the execution speed of a service task that provides a service by using state change information of other tasks is improved.

[Brief explanation of drawings]

Fig. 1 is a functional block diagram of the present invention, Fig. 2 is a system configuration diagram of an embodiment, Fig. 3 is a flow chart of messages between tasks in an embodiment, and Fig. 4 is an operation of each task in an embodiment. Flowcharts: FIG. 5 is an explanatory diagram of the operation of the trash can service; FIG. 6 is an explanatory diagram of the flow of messages between tasks in the conventional method; and FIG. 7 is an operational flowchart of each task in the conventional method. L... Workstation, 2... Display, 3... Pointing device, 4... Icon group, 5... Service task group, 6... Input/output management means, 7... Task 1 stage of status change notification; 8...Task status management means.

Claims (1)

[Claims] Display (2) and pointing device (
3), and a group of icons (4) on the display (2).
), a workstation (
In 1), the coordinate information input by the pointing device (3) is sent as a message to the service task group (5), and the display of the icon group (4) on the display is managed according to the message from the service task group. an input/output management means (6) for transmitting a message from the input/output management means (6); and a task state change notification means (7) for notifying that the task accessed by the message transmission from the input/output management means (6) changes its state due to the access; The change in status notified by the task status change notification means (7) is transmitted to the service task group (5) as necessary.
A task state management method comprising: task state management means (8) for transmitting a message to each task in the task state management system.