Boots – shoes – and leggings
Patent
1992-06-19
1995-05-09
Black, Thomas G.
Boots, shoes, and leggings
395650, 395725, 3642468, 3642813, 3642815, 3642816, 3642822, 3642832, 364DIG1, G06F 1200
Patent
active
054148391
ABSTRACT:
Requests for memory locks upon nodes in a multi-level resource hierarchy of a computer system are granted and denied by a hybrid escalation/de-escalation protocol that dynamically modifies the resource hierarchy so that lock escalation may restrict the extent of the hierarchy. Each of the leaf-level nodes, for example, is identified by a flag indicating whether or not it is possible to further refine a lock on the node by de-escalation. During escalation from a lower level of the hierarchy to a higher-level node, the flag for the higher-level node is set to restrict the extent of the hierarchy and to free-up memory previously allocated to descendants of the higher-level node. In a specific embodiment, the lock protocol attempts to place a strong lock at the highest possible node in the portion of the resource hierarchy including an object to be locked, and also records in memory a leaf node instance for the object. Another conflicting request, however, may cause de-escalation of the strong lock toward the leaf-levels of the hierarchy. Escalation of leaf-level locks is attempted just before the lock protocol would otherwise record a leaf node instance for an additional object. Lock escalation is performed by recording a leaf node instance for the ancestor node and de-allocating the memory that was used to store leaf-level node instances of the descendants of the ancestor.
REFERENCES:
patent: 4698752 (1987-10-01), Goldstein et al.
patent: 4716528 (1987-12-01), Crus et al.
patent: 4914569 (1990-04-01), Levine et al.
patent: 5063501 (1991-11-01), Jordan, Jr.
patent: 5063503 (1991-11-01), Jordan, Jr.
patent: 5063504 (1991-11-01), Jordan, Jr.
patent: 5119490 (1992-06-01), Kurose
patent: 5247672 (1993-09-01), Mohan
patent: 5285528 (1994-02-01), Hart
patent: 5301290 (1994-04-01), Tetzlaff et al.
patent: 5355477 (1994-10-01), Strickland et al.
Hobbs et al., "Rdb/VMS-A Comprehensive Guide," Digital Equipment Corporation, Maynard, Mass. (1991).
Joshi, "Adaptive Locking Strategies in a Multi-node Data Sharing Environment", Proceedings of the 17th International Conference on Very Large Data Bases, (Sep. 3-6, 1992), Barcelona, Spain, IEEE, pp. 181-192.
Lehman et al., "A Concurrency Control Algorithm for Memory-Resident Database Systems," FODO (Jun. 1989), pp. 1-15.
Snaman et al., "The VAX/VMS Distributed Lock Manager," Digital Technical Journal, No. 5, Maynard, Mass. (Sep. 1987), pp. 29-44.
Bernstein et al., "Concurrency Control and Recovery in Database Systems", Addison-Wesley (1987), pp. 58-78.
Gray, Operating System: An Advanced Course, Lecture Notes in Computer Science 60, Springer-Verlag, New York (1977), pp. 394-459.
Bayer et al., "Concurrency of Operations of B-Trees," Acta Inf. 9, 1 (1977), pp. 129-139.
Black Thomas G.
Digital Equipment Corporation
Von Buhr Maria N.
LandOfFree
Hybrid lock escalation and de-escalation protocols does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Hybrid lock escalation and de-escalation protocols, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hybrid lock escalation and de-escalation protocols will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1712696