Method and apparatus for freeing memory in a data processing system

A method in a computer freeing space in a memory, wherein a plurality of objects are present within the memory, the method comprising:

• responsive to an indication that space needs to be freed in the memory, identifying an object within the plurality of objects that is an oldest, least recently used object that is in use in the memory, wherein the object is an identified object and has a set of object attributes;
• inspecting the set of object attributes for the identified object to determine whether the identified object is a candidate for storage in a seldom used object store;
• responsive to a determination that the identified object is a candidate, copying the object to the seldom used object store, wherein the identified object becomes a relocated object;
• adjusting references to the relocated object to a location of the relocated object in the seldom used object store;
• freeing space in the memory occupied by the relocated object;
• receiving a request to allocate space in the memory;
• reclaiming memory space from deleted objects;
• responsive to reclaiming memory, determinig whether sufficient space is available to satisfy the request;
• and
• responsive to a determination that insufficient space is present, generating an indication that space needs to be freed in the memory.

A method for freeing space in a memory in a computer, the method comprising the computer implemented steps of:

• responsive to an indication that space within the memory needs to be freed, identifying an object that is an oldest and least recently used object, wherein the object is an identified object;
• determining whether the identified object is a candidate for storage based on a set of attributes associated with identified object;
• responsive to a determination that the identified object is a candidate, copying the identified object in a storage device;
• adjusting references to the object to point to a location of the identified object in the storage device;
• and
• freeing space occupied by the identified object in the memory.

A Java virtual machine comprising:

• a class loader, wherein the class loader loads classes;
• a runtime data area including:
• a method area, wherein the method area holds class data;
• a heap, wherein the heap holds objects, wherein each object within the heap has a set of attributes;
• and
• a memory manager, wherein the memory manager includes a plurality of modes of operation including:
• a first mode of operation, responsive to an indication that space within the memory needs to be freed in which the memory manager identifies an object in the heap that is an oldest and least recently used object, wherein the object is an identified object;
• a second mode of operation, responsive to the first mode of operation, in which the memory manager determines whether the identified object is a candidate for storage based on a set of attributes associated with identified object;
• third mode of operation, responsive to a determination that the identified object is a candidate, in which the memory manager copies the identified object in a storage device;
• a fourth mode of operation in which the memory manager adjusts references to the identified object to point to a location of the identified object in the storage device;
• and
• a fifth mode of operation, responsive to copying the identified object in the heap to the storage device, in which the memory manager frees space occupied by the object inthe memory.

A data processing system in a computer freeing space in a memory, wherein a plurality of objects are present within the memory, the data processing system comprising:

• identifying means, responsive to an indication that space needs to be freed in the memory, for identifying an object within the plurality of objects that is an oldest, least recently used object that is in use in the memory, wherein the object is an identified object and has a set of object attributes;
• inspecting means for inspecting the set of object attributes for the identified object to determine whether the identified object is a candidate for storage in a seldom used object store;
• copying means, responsive to a determination that the identified object is a candidate, for copying the object to the seldom used object store, wherein the identified object becomes a relocated object;
• adjusting means for adjusting references to the relocated object to a location of the relocated object in the seldom used object store;
• and
• space freeing means for freeing space in the memory occupied by the relocated object.

A data processing system in a computer freeing space in a memory, wherein a plurality of objects are present within the memory, the data processing system comprising:

• identifying means, responsive to an indication that space needs to be freed in the memory, for identifying an object within the plurality of objects that is an oldest least recently used object that is in use in the memory, wherein the object is an identified object and has a set of object attributes;
• inspecting means for inspecting the set of object attributes for the identified object to determine whether the identified object is a candidate for storage in a seldom used object store;
• copying means, responsive to a determination that the identified object is a candidate, for copying the object to the seldom used object store, wherein the identified object becomes a relocated object;
• adjusting means for adjusting references to the relocated object to a location of the relocated object in the seldom used object store;
• space freeing means for freeing space in the memory occupied by the relocated object;
• receiving means for receiving a request to allocate space in the memory,
• reclaiming means for reclaiming memory space from deleted objects;
• determining means, responsive to reclaiming memory, for determining whether sufficient space is available to satisfy the request;
• and
• generating means, responsive to a determination that insufficient space is present, for generating an indication that space needs to be freed in the memory.

A data processing system for freeing space in a memory in a computer, the data processing system comprising:

• identifying means, responsive to an indication that space within the memory needs to be freed, for identifying an object that is an oldest and least recently used object, wherein the object is an identified object;
• determinig means for determining whether the identified object is a candidate for storage based on a set of attributes associated with identified object;
• copying means, responsive to a determination that the identified object is a candidate, for copying the identified object in a storage device;
• adjusting means for adjusting references to the object to point to a location of the identified object in the storage device;
• and
• space freeing means for freeing space occupied by tile identified object in the memory.

A computer program product in a computer readable medium freeing space in a memory, wherein a plurality of objects are present within the memory, the computer program product comprising:

• first instructions, responsive to an indication that space needs to be freed in the memory, for identifying an object within the plurality of objects that is an oldest, least recently used object that is in use in the memory, wherein the object is an identified object and has a set of object attributes;
• second instructions for inspecting the set of object attributes for the identified object to determine whether the identified object is a candidate for storage in a seldom used object store;
• third instructions, responsive to a determination that the identified object is a candidate, for copying the object to the seldom used object store, wherein the identified object becomes a relocated object;
• fourth instructions for adjusting references to the relocated object to a location of the relocated object in the seldom used object store;
• and
• fifth instructions for freeing space in the memory occupied by the relocated object.

A computer program product in a computer readable medium for freeing space in a memory in a computer, the computer program product comprising:

• first instructions, responsive to an indication that space within the memory needs to be freed, for identifying an object that is an oldest and least recently used object, wherein the object is an identified object;
• second instructions for determining whether the identified object is a candidate for storage based on a set of attributes associated with identified object;
• third instructions, responsive to a determination that the identified object is a candidate, for copying the identified object in a storage device;
• fourth instructions for adjusting references to the object to point to a location of the identified object in the storage device;
• and
• fifth instructions for freeing space occupied by the identified object in the memory.