Accessing shorter-duration instances of activatable objects based on object references stored in longer-duration memory
View Patent ↗Techniques are provided for accessing an instance of a recreatable object in a shorter-duration memory based on a reference located in a longer-duration memory, where the shorter-duration memory is associated with a call. One technique involves (1) locating, within the shorter-duration memory, a context structure associated with the call; (2) locating an XREF pointers array based on data cached within the context structure; (3) determining whether the XREF pointers array includes a pointer associated with the reference; and (4) if the XREF pointers array includes a pointer associated with the reference, then following the pointer to locate the instance within the shorter-duration memory. Another technique, which may be employed in addition to or instead of the first technique, involves: (1) when a class is activated, generating, within the shorter-duration memory, a class object associated with the class; (2) storing, within the class object, data for locating instances of recreatable objects associated with the class; (3) to dereference the reference, performing the steps of (a) determining that the reference is associated with the class; and (b) using the data within the class object to locate the instance of the recreatable object.
1. A computer-implemented method for accessing an instance of a recreatable object in a shorter-duration memory based on a reference to the instance of the recreatable object located in a longer-duration memory, wherein the shorter-duration memory is associated with a call, the method comprising the steps of:
locating, within the shorter-duration memory, a context structure, wherein at least a portion of the context structure is passed as an argument to the call;
locating an XREF pointers array based on data cached within the context structure, wherein the data cached within the context structure includes a reference to the XREF pointers array;
determining whether the XREF pointers array includes a pointer associated with said reference to the instance of the recreatable object; and
if the XREF pointers array includes a pointer associated with said reference to the instance of the recreatable object, then following said pointer to locate said instance within said shorter-duration memory.
2. The method of claim 1 wherein the step of locating an XREF pointers array based on data cached within the context structure comprises the steps of:
determining a hash code associated with a memory page in which the reference to the instance of the recreatable object located in the longer-duration memory is located;
using at least a portion of the hash code as an index to locate an array entry within an array stored within the context structure; and
if said array entry contains a pointer, then following said pointer stored in said array entry to locate said XREF pointers array.
3. The method of claim 2 wherein:
the array is a power-of-two array; and
the portion of said hash code that is used as said index includes a particular number of bits of said hash code.
4. The method of claim 2 wherein, if said array entry does not contain a pointer:
creating said instance of the recreatable object by activating said recreatable object; and
storing a pointer to said instance of the recreatable object in said array entry.
5. The method of claim 1 wherein, the XREF pointers array does not include a pointer associated with said reference to the instance of the recreatable object, the computer-implemented method further comprising the steps of:
creating said instance of the recreatable object by activating said recreatable object; and
storing a pointer to said instance of the recreatable object in said XREF pointers array.
6. The method of claim 1 wherein the duration of the shorter-duration memory is shorter than the duration of the longer-duration memory.
7. A computer implemented method for accessing an instance of a recreatable object in shorter-duration memory based on a reference located in a longer-duration memory, wherein the shorter-duration memory is associated with a call, the method comprising the steps of:
when a class is activated, generating, within said shorter-duration memory, a class object associated with the class;
storing, within said class object, data for locating instances of recreatable objects associated with said class, wherein said data includes a pointer to an XREF pointers array;
to dereference said reference located in a longer-duration memory, performing the steps of:
determining that said reference located in a longer-duration memory is associated with said class; and
using said data within said class object to locate said instance of said recreatable object.
8. The method of claim 7 wherein the step of using said data within object to locate said instance includes the steps of:
determining whether the XREF pointers array includes a pointer associated with said reference; and
if the XREF pointers array includes a pointer associated with said reference, then following said pointer to locate said instance within said shorter-duration memory.
9. The method of claim 8 wherein:
the XREF pointers array does not include a pointer associated with said reference; and
the method further comprises the steps of
creating said instance by activating said recreatable object; and
storing a pointer to said instance in said XREF pointers array.
10. A computer-readable storage medium stores instructions for accessing an instance of a recreatable object in a shorter-duration memory based on a reference to the instance of the recreatable object located in a longer-duration memory, wherein the shorter-duration memory is associated with a call, the computer-readable medium comprising instructions for performing the steps of:
locating, within the shorter-duration memory, a context structure, wherein at least a portion of the context structure is passed as an argument to the call;
locating an XREF pointers array based on data cached within the context structure, wherein the data cached within the context structure includes a reference to the XREF pointers array;
determining whether the XREF pointers array includes a pointer associated with said reference to the instance of the recreatable object; and
if the XREF pointers array includes a pointer associated with said reference to the instance of the recreatable object, then following said pointer to locate said instance within said shorter-duration memory.
11. The computer-readable medium of claim 10 wherein the step of locating an XREF pointers array based on data cached within the context structure comprises the steps of:
determining a hash code associated with a memory page in which the reference to the instance of the recreatable object located in the longer-duration memory is located;
using at least a portion of the hash code as an index to locate an array entry within an array stored within the context structure; and
if said array entry contains a pointer, then following said pointer stored in said array entry to locate said XREF pointers array.
12. The computer-readable medium of claim 11 wherein:
the array is a power-of-two array; and
the portion of said hash code that is used as said index includes a particular number of bits of said hash code.
13. The computer-readable medium of claim 11 further comprising instructions for performing the steps of:
if said array entry does not contain a pointer, then creating said instance of the recreatable object by activating said recreatable object; and
storing a pointer to said instance of the recreatable object in said array entry.
14. The computer-readable medium of claim 10 wherein if the XREF pointers array does not include a pointer associated with said reference to the instance of the recreatable object, the computer-readable medium further comprises instructions for performing the steps of:
creating said instance of the recreatable object by activating said recreatable object; and
storing a pointer to said instance of the recreatable object in said XREF pointers array.
15. The computer-readable medium of claim 10 wherein the duration of the shorter-duration memory is shorter than the duration of the longer-duration memory.
16. A computer-readable storage medium stores instructions for accessing an instance of a recreatable object in shorter-duration memory based on a reference located in a longer-duration memory, wherein the shorter-duration memory is associated with a call, the computer-readable medium comprising instructions for performing the steps of:
when a class is activated, generating, within said shorter-duration memory, a class object associated with the class;
storing, within said class object, data for locating instances of recreatable objects associated with said class, wherein said data includes a pointer to an XREF pointers array;
to dereference said reference located in the longer-duration memory, performing the steps of:
determining that said reference located in the longer-duration memory is associated with said class; and
using said data within said class object to locate said instance of said recreatable object.
17. The computer-readable medium of claim 16 wherein the step of using said data within object to locate said instance includes the steps of:
determining whether the XREF pointers array includes a pointer associated with said reference; and
if the XREF pointers array includes a pointer associated with said reference, then following said pointer to locate said instance within said shorter-duration memory.
18. The computer-readable medium of claim 17 wherein:
the XREF pointers array does not include a pointer associated with said reference; and
the computer-readable medium further comprises instructions for performing the steps of:
creating said instance by activating said recreatable object; and
storing a pointer to said instance in said XREF pointers array.