There are provided a heap memory management method that not only improves
processing performance of an application program but also reduces a
program development cost and a computer system using the same method. A
live object copy process in minor collection of generational garbage
collection is implemented through a calculate process of object live
ratio, a compare process of object live ratio, and a live object copy
process. The calculate process of object live ratio calculates a ratio of
a size of a memory allocated to live objects of new objects to a size of
a memory allocated to a new object during minor collection. The compare
process of object live ratio compares a calculated object live ratio with
a predetermined threshold. The live object copy process copies a live
object directly to an old-generation heap instead of a new-generation
heap when the object live ratio exceeds the threshold as a result of
comparison. Further, an application programmer provides means for setting
the threshold that decides a copy destination of the live object as a
runtime parameter of a program and means for holding the set threshold in
a memory.