Abstract: A system for garbage collection of memory objects in a memory heap. The system includes a memory heap that is partitioned into few generations, each generation being partitioned into cards. The generations are associated with remembered sets and card markings data structure. Each card in the card markings data structure includes scan generation related data that represent generations for which the card has or has not to be scanned. The system further includes a processor communicating with the memory for scanning the cards according to the scan generation related data, and in response to identifying updated inter-generational pointers, the processor is capable of updating the remember set with the identified inter-generational pointers. The processor is further capable of updating the scan generation related data.

Abstract: In a computer application having a counter for setting first and second counter values in respect of first and second objects. The counter has a range of n possible values and being incremented or decremented in accordance with update criterion. The application taking an action according to whether the first counter value is larger or equal to the second counter value. A method for handling a courter overflow event whereby the counter is incremented beyond said range by executing the steps of: compacting the first and second counter values to m values (m<n) so as to constitute first and second compacted counter values, such that if the first counter value id larger than or equal to the second counter value then the compacted first value is not smaller than the compacted second value, and setting the counter to a value from among n-m values within the specified range.

Abstract: A system for garbage collection of memory objects in a memory heap. The system includes memory heap that is partitioned into respective old and young areas. The old area is partitioned into cars and is further associated with card markings and remembered sets data structures. The card markings include for each card, a card time stamp that represents the time that the card was updated. The car includes, for each car, a car time entry stamp that represents the time the remembered set of the car was updated. The system further includes a processor communicating with the memory, and being capable of identifying all cards that were updated later than the remembered set of a selected car. In response to the event, it performs identifying change in pointers that refer from the card to a memory object in the selected car and in response to identified change in pointers, updating the remembered set of the car with the identified pointers.