Method of detecting memory leak causing portion and execution program thereof

Abstract

To reduce labor required in investigating on a source of memory leaks with regard to the memory leaks generated in executing a program using a language which does not explicitly indicate release of data region. With regard to a plurality of data stored in a memory, relationship of data is grasped twice after an time interval therebetween. Next, increased data C1, E2, E3 which are not present in data of a first time are extracted from data of a second time, and weights “1”, “2”, “2” in accordance with data sizes are attached to the increased data. Next, the weights are successively propagated from a lower order data of a destination of reference to a higher order data of a source of reference successively. At this occasion, when there are a plurality of lower order data E2, E3 for a higher order D0, a weight constituted by adding the weights “2”, “2” of the plurality of lower data E2, E3 is made to be a weight “4” of the higher order data D0, and the weights of the respective data represent leak scores which causes memory leak.

Description

CLAIM OF PRIORITY [0001] The present application claims priority form Japanese application P2004-116581 filed on Apr. 12, 2004, the content of which is hereby incorporated by reference into this application. BACKGROUND OF THE INVENTION [0002] The present invention relates to a method of detecting a memory leak causing portion generated in executing a program described in a programming language of Java language or the like capable of tracking a data relationship with regard to a plurality of data stored in a memory of a computer and an execution program thereof. [0003] As one of causes by which a computer program does not achieve a performance as expected, there is pointed out a phenomenon referred to as memory leak in which a data memory region used in the program continues to increase. Normally, data generated in executing a program is arranged at a memory region referred to as a heap region. The heap region is a kind of a memory region used in executing a program and is utilized f...

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Benefits of technology

[0009] In view of the above-described problem of the related art, the object of the present invention is to provide a method of detecting a memory leak causing portion capable of reducing labor required for investigating a source of memory leak with regard to memory leak caused by executing a program using a language which does not explicitly indicate release of a data region, and an execution program thereof.

[0040] According to the invention, the weights are attached to the plurality of data constituting the reference relationship, the weights are made to constitute leak scores indicating a possibility of causing the memory leak and therefore, data being the source of causing the memory leak is easy to specify and labor required for investigating on the source of memory leak can be reduced.

Problems solved by technology

When the operation of releasing the ensured region is not executed properly or when data of unfreed area become invisible from the executing system, there is generated a state in which the memory region used by the program continues to increase, that is, the memory leak.

In a case of a language explicitly instructing release of region in the heap region as in C language or C++ language, a memory leak may occur due to a deficiency in release of region.

Further, there may also occur a memory leak by disappearance of a reference to the data storage region ensured in the heap region when other reference is assigned erroneously to a field in the heap region holding the reference to the data storage region before release of the region.

The garbage collection function is a function of collecting data deviated from the data reference relationship and therefore, when there is generated a reference for unnecessary data which is not anticipated by a programmer due to a failure in programming, data does not become an object of collecting by the garbage collection function and this causes a memory leak by which the necessary data continues to increase in the memory.

As described above, in the case of a programming language as Java language, the operation of releasing the data region is not explicit and therefore, it is extremely difficult to specify the leak causing portion in the program, and the method of detecting a memory leak causing portion used for C language or C++ language cannot be used.

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