Method of tracing object allocation site in program, as well as computer system and computer program therefor

A computer implemented method comprising:

• allocating in a memory, from an object allocation site within a program, a run-time object having a hash-value field comprising a hash value identifying the run-time object from among other run-time objects of a class, wherein the object allocation site is a site in a program allocating the run-time object;
• embedding into the hash-value field as at least a part of the hash value identifying the run-time object from among other run-time objects of a class, in response to allocating the run-time object, an allocation site identifier corresponding to the allocation site, wherein the embedding comprises embedding a static identifier value directly identifying the allocation site within the class;
• replacing the static identifier value in the hash-value field with a calculated value in response to a determination of a first execution of a reference command that accesses the hash-value field of the run-time object,
• the calculated value comprising a first value being unrelated to the allocation site and the calculated value further comprising an allocated object identifier, separate from the first value, the allocated object identifier uniquely identifying objects allocated by the allocation site;
• and
• creating a correspondence table storing a correspondence between the first value and the allocation site.

A computer system for tracing an object allocation site from a run-time object, the computer system comprising:

• a memory that stores the run-time object;
• an allocation unit configured to:
• allocate in the memory, from an object allocation site, a run-time object having a hash-value field comprising a hash value identifying the run-time object from among other run-time objects of a class, wherein the object allocation site is a site in a program allocating the run-time object;
• and
• embed into the hash-value field as at least a part of the hash value identifying the run-time object from among other run-time objects of a class, in response to
• allocating the run-time object, an allocation
• site identifier corresponding to the allocation site;
• an acquirer configured to acquire the hash value from the hash-value field;
• and
• an identification unit configured to:
• determine an acquiring the hash-value is a first access of the hash-value field of the run-time object;
• generate, in response to determining the acquiring the hash-value field is the first access of the hash-value field, a first value that is unrelated to the allocation site;
• record, into a first correspondence table in response to generating the first value, a correspondence between the first value and information identifying the allocation site;
• store, in response to a determination that the acquiring the hash-value field is a first access of the hash-value field of the run-time object, the first value as a first component of the hash value;
• and
• identify, in response to an allocation in the memory, the object allocation site based upon the first value and the correspondence, the identification unit further configured to identify by at least obtaining, from the first correspondence table, the correspondence between the first value within the hash value acquired from the hash-value field of the run-time object, and information for identifying the allocation site that corresponds to the first value, thus identifying the allocation site that corresponds to the first value.