JPH03103941A - Automatic commitment control system - Google Patents

Abstract

PURPOSE:To simplify a program by providing a before journal monitor means, a lock list monitor means, and a roll back monitor means to eliminate a need for a user to preliminarily forecast the volume of a before journal and a lock list. CONSTITUTION:A before journal monitor means 1 which performs the commitment processing to abandon the before journal and the lock list 2 of a process at the time of forecasting overflow of the before journal and a lock list monitor means 2 which performs the commitment processing at the time of forecasting overflow of the lock list are provided. A roll back monitor means 3 is provided which performs the commitment processing after execution of the roll back processing caused by dead lock after the last commitment processing of the process. Thus, it is unnecessary for a user to pay his attention to the timing of the commitment processing, and the program is simplified, and the before journal and the lock list are effectively used at its maximum to improve the processing performance.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an automatic commitment control system in exclusive access processing of shared files in a computer.

[Conventional technology]

Generally, exclusive control over a shared file is achieved through commitment processing performed at appropriate timing by each process that uses the file.

Conventionally, the user has set the before-a-journal output amount and the lock list usage amount in advance, and the program has been designed so that commitment processing is performed before the amount is reached. Furthermore, when deadlocks occur continuously, the timing of file access is adjusted to avoid the occurrence of consecutive deadlocks.

[Problem to be solved by the invention]

The conventional commitment method described above has the disadvantage that the program tends to become complicated because the user needs to be aware of the regularity of shared file access and predict the amount of the before journal and lock list in advance. Also,
When deadlocks occur continuously, unnecessary waiting time is required to adjust the timing of file access, which has the disadvantage of inevitably reducing processing efficiency.

[Means to solve the problem]

The automatic commitment control method of the present invention is designed to prevent automatic commitment processing that is called at any time from a process that exclusively refers to or updates a shared file in a computer, when the before journal is predicted to overflow. Before journal monitoring means performs commitment processing to discard journals and lock lists; Lock list monitoring means performs the comics processing when overflow of the lock list is predicted; and after the last commitment processing performed in the process. and rollback monitoring means for performing the commitment processing after the rollback processing due to deadlock has been performed.

〔Example〕

Next, the present invention will be explained using the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, the automatic commitment control system 10 includes a before journal monitoring means 1, a lock list monitoring means 2, a rollback monitoring means 3, and a commitment processing 4.

FIG. 2 is a flowchart of shared file update processing, and FIG. 3 is a flowchart of automatic commitment control processing.

Referring to FIG. 2, the transaction file and the shared file to be updated are opened (step 20), and the commitment process 4 is called (step 21). Next, a transaction is input from the transaction file (step 22), and it is checked whether the transaction file exists (step 23).

If no transaction exists, close the transaction file and shared file (step 2C)
, calls commitment processing 4 (step 2D) and ends all processing. If a transaction exists,
Lock processing (step 24) for reserving update of data in the shared file corresponding to the transaction.
) and check the results (step 25).

As a result, if a deadlock has occurred, rollback processing (step 26) is performed, and immediately after the last commitment processing (step 22) is executed, the rolled back processing is re-executed. Processing continues. If no deadlock has occurred, data in the shared file corresponding to the input transaction is input (step 27), and the result is checked (step 28).

As a result, if there is no data to be updated, the process returns to the next transaction input process (step 22). If there is data to be updated, the data is output as a before journal to the journal refinement (step 29), the data is updated (step 2A), and automatic commitment processing is requested (step 2B) to execute the next transaction. The process returns to the input process (step 22).

Referring to FIG. 3, first, the number of times (X) that automatic commitment has been requested since the execution of the commitment process is counted up (step 3o), and the before journal monitoring means 1 is called. Before journal monitoring means 1
is the commitment process - 5 = 6 The amount of before journal accumulated since execution (Jou
t) plus the average value (Jout/X) of the before journals output at the automatic commitment request interval, it is checked whether or not it exceeds the before journal storage capacity (Jmax) (step 31). Commitment processing 4 is called, otherwise lock list monitoring means 2 is called.

The lock list monitoring means 2 calculates the average value (Luse) of the number of data locked at the auto-commitment interval request interval to the number of data locked after the execution of the commitment process (Luse).
It is checked (step 32) whether the value obtained by adding L s e / Call means 3.

The rollback monitoring means 3 checks whether the number of rollback executions (Rcnt) due to deadlock since the previous execution of the commitment process is 1 or more (step 33), and if it is 1 or more, the commit is canceled.・ment processing 4
Otherwise, return to the requester for automatic commit processing.

Commitment processing 4 discards the accumulated before journal and unlocks the update data (step 34), initializes the number of automatic commitment requests (X) and the number of rollback executions (Rcnt) (step 35), and Return to the source of the commitment processing request.

〔Effect of the invention〕

As explained above, the present invention simplifies the program because the user does not need to be aware of the timing of commitment processing in exclusive access processing of shared files in a computer, and furthermore, the before journal and lock list can be minimized. This has the effect of improving processing performance since it is used effectively to the maximum extent possible.

Furthermore, since commitment processing can be performed as early as possible in file access after a deadlock occurs, it is possible to prevent consecutive deadlocks from occurring.

Furthermore, the first automatic commitment request after a deadlock occurs will always execute the commitment process even if the before journal or lock list overflow is not predicted, so a deadlock will occur before the above automatic commitment request. If this is not done, the file access processing will proceed steadily even if a deadlock occurs in the future.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a flowchart of shared file update processing, and FIG. 3 is a flowchart of an automatic commitment control system. ■... Before journal monitoring means, 2... Lock list monitoring means, 3... Rollback monitoring means, 4.
... Commitment processing, 10... Automatic commitment control method. Figure 1

Claims (2)

[Claims] (1) In automatic commitment processing that is called at any time from a process that exclusively references and updates shared files in a computer, the before journal and lock list of the process are discarded when an overflow of the before journal is predicted. a before journal monitoring unit that performs commitment processing when the lock list overflow is predicted; and a lock list monitoring unit that performs the commitment processing when the lock list is predicted to overflow; and a lock list monitoring unit that performs the commitment processing when the lock list overflow is predicted; An automatic commitment control system comprising: rollback monitoring means for performing the commitment process after the back process has been performed. (2) In automatic commitment processing that is called at any time from a process that exclusively references and updates shared files in a computer, when an overflow of the before journal is predicted, the before journal and lock list of the process are discarded. The commitment process is executed when the lock list is expected to overflow, and after the rollback process due to deadlock has been performed since the last commitment process in the process. An automatic commitment control method characterized in that the commitment process is executed at a certain time.