Method and computer program product to reuse directory search handles

• US 5,765,192 A
• Filed: 05/01/1996
• Issued: 06/09/1998
• Est. Priority Date: 05/01/1996
• Status: Expired due to Term

• Current Assignee: Oracle America, Inc. (Oracle Corporation)
• Original Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Inventors: Berliner, Brian
• Primary Examiner(s): Black, Thomas G.
• Assistant Examiner(s): HOMERE, JEAN RAYMOND
• Application Number:
  US08/639,531
• Time in Patent Office: 769 Days
• Field of Search: 395/622, 395/621, 395/463, 395/471, 395/487, 395/497.04, 395/415, 707/205, 707/206, 707/3, 711/113, 711/136, 711/205, 711/207
• US Class Current: 711/136
• CPC Class Codes: G06F 12/0866 for peripheral storage systems, e.g. disk cache
• CPC Class Codes: G06F 16/10 File systems; File servers
• CPC Class Codes: G06F 2212/311 In host system
• CPC Class Codes: Y10S 707/99933 Query processing, i.e. searching
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

A method is disclosed for reusing directory search handles in a manner that minimizes the possibility that a handle allocated for a directory search request that is not yet complete will be reused. This method is implemented by assigning a block of system memory at the time of system initialization for the creation of a set of directory search and information retrieval handle structures. Handle structures within the set are allocated as they are needed. When all have been allocated, they are reused, one at a time in a least-recently-used fashion which gives preference to handle structures which have the lowest probability of being associated with an incomplete search request.

Claims

1. A method for creating and using handle data structures employed in the processing of directory search requests, said method comprising the steps of:

providing for assigning a block of system memory at the time of system initialization and creating a set of unused handle structures within that block;

providing for determining if a directory search request requires a handle so that the directory search request can be processed;

providing for allocating and using the created unused handle structures as they are needed for processing individual directory search requests as determined by said determining step;

providing for selecting and reusing a previously-used handle structure when all unused handle structures have been allocated for previous uses.

2. The method of claim 1, wherein said step of providing for selecting and reusing a previously-used handle structure is accomplished in a least-recently-used fashion.

3. The method of claim 2, wherein said step of providing for selecting and reusing a previously-used handle structure is accomplished in a manner which gives preference to handle structures having the lowest probability of being associated with an incomplete search request.

4. The method of claim 3, wherein preference in reusing previously used handle structures is given to handle structures in the following descending order of preference:

(a) previously used handle structures which are marked "done";

(b) previously used handle structures which are marked "not done", but which have not been involved in search requests involving a wildcard file designation; and

(c) previously used handle structures which are marked "not done", but which have been involved in search requests involving a wildcard file designation.

5. A method for creating and using handle data structures employed in the processing of directory search requests, said method comprising the steps of:

assigning a block of system memory at the time of system initialization and creating a set of unused handle structures within that block;

determining if a directory search request requires a handle so that the directory search request can be processed;

allocating and using the created unused handle structures as they are needed for processing individual directory search requests as determined by said determining step;

selecting and reusing a previously-used handle structure when all unused handle structures have been allocated for previous uses.

6. The method of claim 5, wherein said step of selecting and reusing a previously-used handle structure is accomplished in a least-recently-used fashion.

7. The method of claim 6, wherein said step of selecting and reusing a previously-used handle structure is accomplished in a manner which gives preference to handle structures having the lowest probability of being associated with an incomplete search request.

8. The method of claim 7, wherein preference in reusing previously used handle structures is given to handle structures in the following descending order of preference:

(a) previously used handle structures which are marked "done";

(b) previously used handle structures which are marked "not done", but which have not been involved in search requests involving a wildcard file designation; and

(c) previously used handle structures which are marked "not done", but which have been involved in search requests involving a wildcard file designation.

9. A computer program product comprising a computer usable medium having computer readable code embodied therein for creating and using handle data structures employed in the processing of directory search requests, the computer program product comprising:

computer readable program code devices configured to cause a computer to effect assigning a block of system memory at the time of system initialization;

computer readable program code devices configured to cause a computer to effect creating a set of unused handle structures within the block of system memory;

computer readable program code devices configured to cause a computer to effect determining if a directory search request requires a handle so that the directory search request can be processed;

computer readable program code devices configured to cause a computer to effect allocating and using the created unused handle structures as they are needed for individual directory search requests; and

computer readable program code devices configured to cause a computer to effect selecting and reusing a previously-used handle structure when all unused handle structures have been allocated for previous uses.

10. The computer program product of claim 9, which further comprises computer readable program code devices configured to cause a computer to effect selection and reuse of a previously-used handle structure in a least-recently-used fashion.

11. The computer program product of claim 10, which further comprises computer readable program code devices configured to cause a computer to effect selection and reuse of a previously-used handle structure in a manner which gives preference to handle structures having the lowest probability of being associated with an incomplete search request.

12. The computer program product of claim 10, which further comprises computer readable program code devices configured to cause a computer to effect a preference in reusing previously used handle structures in the following descending order of preference:

(a) previously used handle structures which are marked "done";

(b) previously used handle structures which are marked "not done", but which have not been involved in search requests involving a wildcard file designation; and

(c) previously used handle structures which are marked "not done", but which have been involved in search requests involving a wildcard file designation.