Method of recognizing fixed and variable sized data objects in memory

In a data processing system having multiple memory heaps, wherein said heap includes a pool page structure for storing fixed size objects, said pool page structure comprising:

• (a) a pool page for each fixed size object of interest;
• (b) each of said pool pages including a header portion and a body portion;
• (c) said header portion comprising information fields for storing information corresponding to the fixed size object of interest, said information fields including an identification field for identifying the object type for that page, a heap field for identifying the heap for the object and a size field for indicating the size of object reserved for that page;
• and
• (d) said body portion providing means for allocating objects of the fixed size for said page.

Data storage media recorded with a computer program which, in combination with a general purpose computer loaded with an operating system and runtime library means, and equipped to read into memory and execute program data from the data storage media, comprises a method for freeing fixed and variable size objects in response to a runtime free request from a user application executing in said operating system wherein said runtime library means specifies the address of the object in memory, the object having been previously allocated in a memory heap, said method including the steps of:

• (a) determining a pool page address from the address of the object to be freed and addressing said pool page;
• (b) determining if the object to be freed is a fixed size object on the basis of a selected value stored in known location on the pool page addressed in step (a);
• (c) if the object is a fixed size object, freeing the object from the Pool page addressed in step (a);
• (d) if the object is not a fixed size object, addressing the object to be freed and freeing the object as a variable size object.