Fujitsu Corporation

Katsutomo Sekiguchi

Masakazu Hayashi

Yukihiro Kimura

In a computer-readable storage medium storing a generational garbage collection program used to direct a computer to perform a generational garbage collection process, the generational garbage collection process includes a generational garbage collection environment preparing and initializing process, and the generational garbage collection environment preparing and initializing process includes a process of allocating a single virtual memory space as a virtual memory space of all generations, and distributing the single virtual memory space to each generation such that the virtual memory space of each generation can be continuously arranged in order of generation in the single virtual memory space.

Computer-readable storage medium storing generational garbage collection program

Measurement/analysis unit in a Java virtual machine has the function of measuring data when an event of garbage collection occurs, and the function of periodically measuring data. The measurement/analysis unit analyzes the measured data and predicts a danger of a memory shortage, and predicts a danger using an algorithm depending on the type of garbage collection used by the Java virtual machine. An application server is notified of a warning of the predicted danger of a memory shortage by an analysis result notification means by an inter-process communication, or the like. The measurement/analysis unit calculates a memory capacity required to avoid the predicted danger of a memory shortage, and the calculated memory capacity is transmitted to the application server by the analysis result notification means by an inter-process communication, or the like in the same way as the warning.

Method for predicting and avoiding danger in execution environment

A logging unit logs data, including data on object generation/access and start/end of GC, information about object longevity when GC is performed, and data about a method call/return or the like. An analyzing unit organizes by object logged records, sorts that information about each object by time or size, and obtains changes in required heap size and a longevity characteristic of each object. An estimating unit uses a required heap size data and the object longevity characteristic to estimate an optimum heap size according to a criterion specified by a user.

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Kawasaki, Japan

Katsutomo Sekiguchi