JPH05143423A - On-line journal acquiring system - Google Patents

Abstract

PURPOSE:To reduce the internal processing of a CPU by decreasing the number of times for issuing a supervisor call concerning wait and wait release by starting the journal output operation of a following task without informing it of the following task after the journal output operation of a preceding task is completed, and releasing the wait of the following task when the started output operation is completed. CONSTITUTION:When a preceding task 1 is under outputting journal information 1, a following task demands the output operation start of journal information 2 to the preceding task 1 and is turned to a waiting state according to the WAIT supervisor call until the operation is completed. When the output operation of the journal information 1 is completed, the preceding task 1 starts the output operation of the journal information 2 in place of the task 2 and finishes the processing. When the wait of the task 2 is released by the POST supervisor call showing the completion of this output operation, a series of processings are completed. Thus, the WAIT and POST supervisor calls for communication between the tasks 1 and 2 are omitted and performance can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an online journal acquisition system adopted to eliminate a CPU internal processing neck at the time of acquiring rerun journal information which occurs in a high traffic online system.

[0002]

2. Description of the Related Art Conventionally, in the case of acquiring an online journal, as described in JP-A-62-266643, when a journal acquisition request is issued during the output operation of the preceding task, the succeeding task queues the journal information. Then, it waits for the contact from the preceding task. The same applies to subsequent tasks that arrive after this. When the output operation of the preceding task is completed, the preceding task contacts the succeeding task to that effect, so that the waiting release means releases the waiting of the succeeding task, and the started succeeding task is output for batch output of the queued journal information. It is a system in which the operation is started, the waiting state is again waited until the output operation is completed, and the waiting is released again after the output operation is completed.

[0003]

Problems to be Solved by the Invention JP-A-62-1666
The method of No. 43 reduces the number of output operations to the journal device and solves the access neck, but there is a problem that the CPU internal processing neck, which largely depends on the number of times of issuing supervisor calls for waiting and releasing the wait, cannot be solved. The present invention is intended to reduce the internal processing of the CPU by reducing the number of times of issuing supervisor calls relating to waiting and waiting release.

[0004]

[Means for solving the problems] In an online system for collecting journal information, when a task is placed in a waiting state to wait for the completion of an I / O operation, and when a task is placed in a waiting state to wait for communication from another task Common to
It has a wait means WAIT supervisor call and a wait release means POST supervisor call, and when a plurality of journal acquisition requests are concentrated, the succeeding task waits for the completion of the input / output operation of the preceding task by the wait means WAIT supervisor call. The method is to serialize the journal acquisition by starting the journal output operation of the succeeding task without contacting the successor task after the completion of the journal output operation of the predecessor task, and then completing the output operation by the POST supervisor call. Release the task wait.

[0005]

In this method, when the succeeding task attempts to output the journal while the preceding task is performing the journal output operation, the succeeding task requests the preceding task to output the journal and enters the waiting state by the waiting means WAIT supervisor call. When the preceding task completes the journal output operation of the invoking task, if there is a journal requested by the succeeding task, it starts outputting the journal and ends the processing related to the journal.

Thereafter, the POST supervisor call for completion of the journal output operation of the succeeding task releases the waiting of the succeeding task, so that the processing relating to the journal of the succeeding task also ends. In this way, by using both waiting for completion of I / O operations and waiting for communication between tasks, the number of supervisor calls relating to waiting and waiting release is reduced, and internal processing overhead is reduced to realize serialization.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention can be particularly advantageously implemented in journal acquisition processing of online systems and database systems. FIG. 2 is a system configuration of an online system to which the present invention is applied. FIG. 3 shows the data format of the acquired journal.

Reference is made to FIG. 1 for a general understanding of the invention. When each task tries to output the journal information, it checks whether there is a preceding task that is already in the output operation in the journal file (step 10), and if it does not exist, it executes the output operation of the invoking task (step 10). 40). After the output operation of the invoking task is completed, check if there is a journal output operation start request from the following task (step 50),
If not, the series of operations ends. At the time of attempting to execute the journal output operation, if there is already a preceding task in output operation in the journal file, the start of the output operation is delegated to the preceding task (step 20), and the invoking task waits for the completion of the output operation. (Step 30). In this case, when the output operation of the preceding task is completed, the presence or absence of a journal output request from the succeeding task is checked (step 50), and since there is a request, the preceding task starts outputting the journal information of the succeeding task (step 60) and performs a series of operations. finish. When the completion notification of this output operation releases the waiting of the succeeding task, the journal output processing of the succeeding task ends. At this time as well, it is confirmed whether or not the subsequent task makes an output request, and the flow is as described above.

FIG. 4 shows the operation of a task according to the conventional technique. When the preceding task 1 is outputting the journal information 1, the succeeding task 2 is in a waiting state by the WAIT supervisor call until the preceding task 1 receives a notification of completion of output from the preceding task 1. When task 1 completes the output operation, it issues a POST supervisor call to task 2, cancels the wait, and ends the processing. When the task 2 is released from the wait, the output operation of the journal information 2 is started
Wait at T Supervisor Call. After that, when the waiting is released by the POST supervisor call for the completion of the output operation, the series of processing is ended.

FIG. 5 shows the operation of the task of the example in which the present invention is implemented. When the preceding task 1 is outputting the journal information 1, the succeeding task 2 requests the preceding task 1 to start outputting the journal information 2 to the preceding task 1, and waits for the completion with a WAIT supervisor call. It becomes a state. When the output operation of the journal information 1 is completed, the preceding task 1 starts the output operation of the journal information 2 instead of the task 2 and ends the processing. When the waiting of the task 2 is released by the POST supervisor call for the completion of the output operation, the series of processing ends.

Thus, comparing the prior art shown in FIG. 4 with the present invention shown in FIG. 5, a WAIT for communication between tasks
And POST supervisor call are omitted,
This improves performance.

[0012]

According to the method of the present invention, the number of supervisor calls relating to communication processing between tasks is reduced. For example, when applied to a journal acquisition process of an online system with high traffic or a database system with high multiplicity, the number of dynamic steps per transaction can be reduced, and the processing capacity per unit time can be increased.

[Brief description of drawings]

FIG. 1 is a flow chart showing an outline of an embodiment of the present invention.

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

FIG. 3 is a diagram showing a data structure of a journal file according to the embodiment of this invention.

FIG. 4 is a diagram showing an operation of a task according to a conventional technique for explaining an embodiment of the present invention.

FIG. 5 is a diagram showing an operation of a task according to this method for explaining the effect of the embodiment of the present invention.

[Explanation of symbols]

 1 ... Terminal, 2 ... Transmission network, 3 ... Processing device, 4 ... Journal file.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Asahi Miyazaki 6-81, Onoe-cho, Naka-ku, Yokohama-shi, Kanagawa, Hitachi Software Engineering Co., Ltd. (72) Norihiro Goto Inoue-cho, Naka-ku, Yokohama, Kanagawa 81-chome Nititsu Software Engineering Co., Ltd.

Claims (2)

[Claims] 1. An online system for acquiring journal information, comprising a means for holding a task and a means for releasing the wait, which are common for waiting for completion of input / output operations and communication between tasks, and a plurality of journal acquisition requests are provided. This is a method of serializing journal acquisition by waiting for the completion of the input / output operation of the preceding task by the succeeding task when it is concentrated. After the completion of the journal output operation of the preceding task, the succeeding task continues without contacting the subsequent task. An online journal acquisition method that starts the journal output operation of a task and releases the waiting of the succeeding task when the output operation is completed. 2. An online system for acquiring journal information, which is common when a task is placed in a waiting state to wait for the completion of an input / output operation and when a task is placed in a waiting state to wait for contact from another task. Waiting means WAIT
It has a supervisor call and a POST supervisor call means to release the wait. When multiple journal acquisition requests are concentrated, the succeeding task waits for the completion of the input / output operation of the preceding task with the waiting means WAIT supervisor call to acquire the journal. Is a method of serializing, and after the journal output operation of the preceding task is completed, the journal output operation of the subsequent task is started without contacting the subsequent task, and the output operation is completed. Wait for the subsequent task with the POST supervisor call. An online journal acquisition method that is characterized by canceling.