Information control system for reserve locking infrastructure nodes for subsequent exclusive and share locking by the system

• US 5,063,504 A
• Filed: 12/18/1989
• Issued: 11/05/1991
• Est. Priority Date: 12/18/1989
• Status: Expired due to Term

• Current Assignee: American Telephone & Telegraph Company (AT&T, Inc.), Bell Telephone Laboratories, Inc. (Nokia Corporation)
• Original Assignee: AT&T, Inc.
• Inventors: Jordan, John D. Jr.
• Primary Examiner(s): MacDonald, Allen R.
• Assistant Examiner(s): Sheikh, Ayaz R.
• Application Number:
  US07/452,093
• Time in Patent Office: 687 Days
• Field of Search: 364/200, 364/900
• US Class Current: 710/200
• CPC Class Codes: G06F 16/1774 Locking methods, e.g. locking methods for file systems allowing shared and concurrent access to files

Abstract

Apparatus and method for controlling concurrent process access of infrastructures. The apparatus and method selectively locks nodes and tree structures to reserve lock a node and tree structure for subsequent exclusive and share locking by a process. Currently running processes have share read only access to the reserved locked node and tree structure until a subsequent exclusive lock is applied by the process to the reserve locked node and tree structure.

Claims

1. Apparatus for controlling concurrent process operations against a complex infrastructure comprising tree structures of complex object nodes wherein said apparatus comprises

means responsive to requests of the process operations for exclusively locking nodes and tree structures to enable the requesting process operations to write information into and read information from said exclusively locked nodes and for share locking nodes and tree structures to enable multiple ones of the process operations to read information from said share locked nodes, and

means responsive to a request of one of the process operations for selectively reserve locking one of the nodes and tree structures to reserve the node and tree structure for subsequent exclusive and share locking by the process operation at a time designated by the process operation while enabling other ones of the process operations to share access to the reserve locked nodes until a subsequent exclusive lock is applied to said reserve locked node by said one of the process operations.

2. The infrastructure controlling apparatus set forth in claim 1 comprising

means responsive to a process operation requesting a lock for a node for selecting said node and generating a list of ancestral nodes related to said selected node.

3. The infrastructure controlling apparatus set forth in claim 2 comprising

means operative upon selecting said node and generating said list of ancestral nodes for comparing a compatibility of an intermediate lock corresponding with said requested lock of each listed ancestral node with a current lock status of the ancestral node.

4. The infrastructure controlling apparatus set forth in claim 3 comprising

means operative upon determination of compatibility of said intermediate lock with each ancestral node current lock status for setting a register corresponding with the ancestral node to record an application of said intermediate lock corresponding with said requested lock to the ancestral node.

5. The infrastructure controlling apparatus set forth in claim 4 comprising

means enabled upon setting all ancestral node registers to record application of said intermediate lock corresponding with said requested lock for locking said selected node in accordance with said requested lock.

6. The infrastructure controlling apparatus set forth in claim 5 comprising

means operative upon detecting a recorded node and tree structure reserve lock for preventing other ones of the process operations from obtaining exclusive and other reserve locks on said node and tree structures having recorded said reserve lock.

7. The infrastructure controlling apparatus set forth in claim 6 comprising

means operative upon detecting a reserve locked node and tree structure of the infrastructure for enabling said other process operations to apply share locks on said node and tree structures having recorded said reserve lock thereby enabling said other process operations to only read information from said reserve locked node and tree structures.

8. Apparatus for controlling concurrent process operations against a complex infrastructure comprising tree structures of complex object nodes wherein said apparatus comprises

means responsive to a process operation requesting a lock for selecting a node and tree structure and generating a list of ancestral nodes related to said selected node and tree structure,

means operative upon selecting said node and generating said list of ancestral nodes for comparing a compatibility of an intermediate lock corresponding with said requested lock of each listed ancestral node with a currently recorded ancestral node lock status,

means operative upon determination of compatibility of said intermediate lock with each ancestral node current recorded lock status for applying said intermediate lock to said ancestral node,

means enabled upon recording said intermediate lock as pending for all said ancestral nodes for comparing said requested lock with a current lock status of said selected node and when compatible therewith for locking said selected node in accordance with said requested lock,

means operative upon detecting a reserve lock recorded in a node and tree structure for preventing other ones of the processes from obtaining exclusive and other reserve locks on said node and tree structure having recorded said reserve lock, and

means operative upon detecting a reserve lock recorded in a node and tree structure of the infrastructure for enabling said other processes to apply share locks on said node and tree structures having recorded said reserve lock thereby enabling said other processes to concurrently read information from said reserve locked node and tree structure nodes.

9. A computer implemented method for controlling concurrent process operations against a complex infrastructure having tree structures of complex object nodes comprising the steps of

selectively locking one of the nodes and each ancestral tree structure node of the one node in response to a request of one of the process operations to reserve lock the node and tree structure ancestral nodes for subsequent exclusive and share locking by the process operation, and

enabling other ones of the process operations to share access to the reserve locked nodes until a subsequent exclusive lock is applied to said reserve locked node by said one of the process operations.

10. The computer implemented method of controlling concurrent process operations against a complex infrastructure as set forth in claim 9 comprising the step of

selecting the node in response to the process operation requesting a lock of the node and generating a list of ancestral nodes related to said selected node.

11. The computer implemented method of controlling concurrent process operations against a complex infrastructure as set forth in claim 10 comprising the step of

comparing a compatibility of an intermediate lock corresponding with said requested lock of each listed ancestral node with a current lock status of the ancestral node.

12. The computer implemented method of controlling concurrent process operations against a complex infrastructure as set forth in claim 11 comprising the step of

setting each ancestral node to an intermediate lock corresponding with said requested lock upon determination of a compatibility of said intermediate lock with each ancestral node current lock status.

13. The computer implemented method of controlling concurrent process operations against a complex infrastructure as set forth in claim 12 comprising the step of

determining upon setting all ancestral nodes of said selected node to said intermediate lock a compatibility of said requested lock with a current lock status of said selected node and when compatible therewith locking and recording said requested lock in said selected node.

14. The computer implemented method of controlling concurrent process operations against a complex infrastructure as set forth in claim 13 comprising the step of

preventing other ones of the process operations from obtaining exclusive and other reserve locks on said node and tree structure nodes having recorded said reserve lock.

15. The computer implemented method of controlling concurrent process operations against a complex infrastructure as set forth in claim 14 comprising the step of

enabling said other process operations to apply share locks to said node and tree structure nodes having recorded said reserve lock thereby making it possible for said other process operations to read data from said reserve locked node and tree structures.

16. Computer apparatus for controlling concurrent process operations against a data base comprising tree structures of complex object nodes of information wherein said computer apparatus comprises

means responsive to requests of the process operations for exclusively locking nodes and tree structures of nodes to enable the requesting process operations to write information into and read information from said exclusively locked nodes and for share locking said nodes and tree structures to enable multiple ones of the process operations to read information from said share locked nodes, and

means responsive to requests of each of said process operations for selectively locking ones of the nodes and tree structures to reserve the node and tree structure for subsequent exclusive and share locking by said each process operation at a time designated by said each process operation while enabling other ones of the process operations to share access to the reserve locked nodes until a subsequent exclusive lock is applied by said each process operation to the reserve locked nodes.