Method and system for determining memory usage of a heap

A computer program product in a recordable-type computer readable medium for determining heap memory utilization, comprising:

• first instructions for detecting an event associated with objects in a heap;
• second instructions for determining if the event is an object allocation event;
• third instructions for, in response to determining that the event is an object allocation event, determining an allocation count since a last mark-and-count operation;
• fourth instructions for determining if the allocation count since the last mark-and-count operation is equal to or greater than a predetermined threshold;
• fifth instructions for, in response to determining that the allocation count since the last mark-and-count operation is equal to or greater than the predetermined threshold, performing a mark-and-count operation, wherein the mark-and-count operation is performed only when the allocation count since a last mark-and-count operation is equal to or greater than the predetermined threshold;
• and
• sixth instructions for outputting information representative of the heap memory utilization based on data collected during the mark-and-count operation, wherein the fifth instructions for performing the mark-and-count operation include:
• instructions for marking live objects in the heap in response to determining that the event is an object allocation event;
• and
• instructions for generating a live count based on the marking of live objects in the heap, wherein the live count is a count of a number of memory bytes allocated to live objects in the heap.

A data processing system, comprising:

• a computing device;
• and
• a mechanism for determining heap memory utilization, comprising:
• means for detecting an event associated with objects in a heap;
• means for determining if the event is an object allocation event;
• means for, in response to determining that the event is an object allocation event, determining an allocation count since a last mark-and-count operation;
• means for determining if the allocation count since a last mark-and-count operation is equal to or greater than a predetermined threshold:
• means for, in response to determining that the allocation count since a last mark-and-count operation is equal to or greater than a predetermined threshold, performing a mark-and-count operation1 wherein the mark-and-count operation is performed only when the allocation count since a last mark-and-count operation is equal to or greater than the predetermined threshold;
• and
• means for storing information representative of the heap memory utilization based on data collected during the mark-and-count operation in a storage device such that the information may be retrieved and used to generate a representation of the heap memory utilization on the computing device, wherein the means for performing the mark-and-count operation includes:
• means for marking live objects in the heap in response to determining that the event is an object allocation event;
• and
• means for generating a live count based on the marking of live objects in the heap, wherein the live count is a count of a number of memory bytes allocated to live objects in the heap.

A method, in a data processing system, for determining heap memory utilization, comprising:

• detecting an event associated with objects in a heap;
• determining if the event is an object allocation event;
• in response to determining that the event is an object allocation event, determining an allocation count since a last mark-and-count operation;
• determining if the allocation count since the last mark-and-count operation is equal to or greater than a predetermined threshold;
• in response to determining that the allocation count since the last mark-and-count operation is equal to or greater than the predetermined threshold, performing a mark-and-count operation, wherein the mark-and-count operation is performed only when the allocation count since a last mark-and-count operation is equal to or greater than the predetermined threshold;
• determining an absolute peak live count from a previous mark-and-count operation;
• determining a number of memory bytes allocated to live objects at a last mark-and-count operation;
• and
• determining if a function of the allocation count since the last mark-and-count operation (X), the absolute peak live count from a previous mark-and-count operation (Z), and the number of memory bytes allocated to live objects at a last mark-and-count operation (Y) meets a predetermined criteria that includes determining if the following relationship is satisfied:
• X+Y<Z+T
• where T is a predetermined tolerance value;
• and
• outputting information representative of the heap memory utilization based on data collected during the mark-and-count operation, wherein the mark-and-count operation includes:
• marking live objects in the heap in response to determining that the event is an object allocation event;
• and
• generating a live count based on the marking of live objects in the heap, wherein the live count is a count of the number of memory bytes allocated to live objects in the heap.