Information control system for selectively transferring a tree lock from a parent node to a child node thereby freeing other nodes for concurrent access

• US 5,063,501 A
• Filed: 12/18/1989
• Issued: 11/05/1991
• Est. Priority Date: 12/18/1989
• Status: Expired due to Term

• Current Assignee: 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:
  US07/452,096
• 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 comprising tree structures of complex object nodes of information. The apparatus and method respond to a request of a computer process by selectively applying a tree lock to a node to lock the node and child nodes located in a tree structure of the tree locked node. Subsequently, the process transports the applied tree lock from the node to selected child nodes located in the tree structure of the node thereby freeing the unlocked node and child nodes thereof for subsequent access by concurrently running ones of the processes.

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 a process operation for selectively applying a tree lock to a node and intermediate tree locks to each ancestral node of said node to lock said node and ancestral nodes and ones of child nodes located in a tree structure of said locked node, and

means responsive to said process operation for subsequently applying said tree lock to ones of said child nodes located in said tree structure and removing said applied tree lock from said node thereby freeing said node and unlocked child nodes located in said tree structure of said node for access by concurrently running one of the process operations.

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

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

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

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

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

means operative upon determination of said compatibility of said intermediate type lock with each ancestral node current lock status for applying said intermediate type lock to each listed ancestral node.

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

means enabled upon applying said intermediate type lock to all listed ancestral nodes for comparing a compatibility of said requested tree lock with a current lock status of said selected node and upon determining said compatibility for applying said requested tree lock to said selected node.

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

means responsive to said process operation for subsequently applying said tree lock to ones of child nodes located in said tree structure and for removing said applied tree lock from said node thereby freeing said node and unlocked child nodes located in said tree structures of said node for access by concurrently running ones of the process operations.

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

means responsive to one of said process operations requesting a tree lock for one of said nodes for selecting said one node and generating a list of ancestral nodes located in a tree structure of said selected node,

means enabled upon selecting said node and generating said list of ancestral nodes for comparing a compatibility of an intermediate type lock corresponding with said requested tree lock with a current lock status of each listed ancestral node,

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

means enabled upon applying said intermediate type lock to all listed ancestral nodes for determining a compatibility of said requested tree lock with a current lock status of said selected node and upon determining said compatibility for applying said requested tree lock to said selected node, and

means responsive to said process operation for subsequently applying said tree lock to ones of said child nodes located in said tree structure and for removing said applied tree lock from said node thereby freeing said node and child nodes located in other tree structures of said node for access by concurrently running ones of the process operations.

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

selectively applying in response to a request of one of the process a tree lock to a node and intermediate tree locks to each ancestral node of said node to lock said node and ancestral nodes and ones of child nodes located in a tree structure of said locked node, and

transporting in response to a subsequent request of said process said applied tree lock from said node to ones of said child nodes located in said tree structure thereby freeing said node and other child nodes located in said tree structure of said node for access by concurrently running ones of the processes.

9. The computer implemented method of controlling concurrent process operations in an infrastructure as set forth in claim 8 wherein said selectively applying step comprises the step of

selecting said node in response to said process request and generating a list of ancestral nodes located in said tree structure of said selected node.

10. The computer implemented method of controlling concurrent process operations in an infrastructure as set forth in claim 9 wherein said selectively applying step comprises the step of

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

11. The computer implemented method of controlling concurrent process operations in an infrastructure as set forth in claim 10 wherein said selectively applying step comprises the step of

applying upon determination of said compatibility of said intermediate type lock with each ancestral node current lock status said intermediate type lock to each listed ancestral node.

12. The computer implemented method of controlling concurrent process operations in an infrastructure as set forth in claim 11 wherein said selectively applying step comprises the step of

comparing upon applying said intermediate type lock to all listed ancestral nodes a compatibility of said requested tree lock with a current lock status of said selected node and upon determining said compatibility applying said requested tree lock to said selected node.

13. The computer implemented method of controlling concurrent process operations in an infrastructure as set forth in claim 12 wherein said transporting step comprises the step of

transporting said tree reserve lock by applying said tree lock to process selected ones of said child nodes located in said tree structure and removing said tree lock from said node in response to said process thereby freeing said node for access by concurrently running processes.

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

selecting in response to a request of one of the processes a tree lock for one of said nodes and generating a list of ancestral nodes located in a tree structure of said node,

comparing a compatibility of an intermediate type lock corresponding with said requested tree lock with a current lock status of each listed ancestral node,

applying said intermediate type lock to each listed ancestral node upon determination of said compatibility of said intermediate type lock with said current lock status of each listed ancestral node,

determining a compatibility of said requested tree lock with a current lock status of said node upon applying said intermediate type lock to all listed ancestral nodes and after determining said compatibility applying said requested tree lock to said node to tree lock said node, and

subsequently applying said tree lock to selected ones of child nodes located in said tree structure of said node and removing said applied tree lock from said node in response to a subsequent request of the process to transport said tree lock to said selected child nodes thereby freeing said node for access by concurrently running processes.