US5469575A
Expired / Lapsed
US
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Determining a winner of a race in a data processing system
Assignee: International Business Machines Corp
•
Filing: 1992-10-16
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Granted: 1995-11-21
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Expires: 2012-10-16
Abstract
Abstract A first peer entity in a data processing system comprising a plurality of similar peer entities searches for a share control file for a system privilege. The share control file contains an address of a master entity which controls the system privilege. The plurality of entities may be either a plurality of peer processors or If the first entity does not find a share control file, it creates a share control file which contains its system and maintain an exclusive write lock on the storage control file address. Each subsequent entity competing for the system privilege will also search for the share control file. However, since the subsequent entities will find the share control file created by the first entity, these entities read the share control file for the address of the master entity. The invention may be used in a multi or single processor environment.
Inventors
- 👤 Hari H. Madduri
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 01:30
CPC Classifications
G; G06; G06F; G06F9/00; G06F9/06; G06F9/46; G06F9/52
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
127 words
In a distributed data processing system including a plurality of peers, a method for determining whether a peer has won a race for a system privilege, the method performed by any one peer of the plurality of peers, comprising the steps of: searching for a share control file in a predetermined location in the distributed data system, the share control file containing an address of a master peer which has the system privilege; responsive to the absence of the share control file, creating a share control file in the predetermined location, the share control file containing an address of the peer to become the master peer; placing an exclusive write lock on the share control file; and, maintaining the exclusive write lock on the share control file.
Claim 2
Dependent Claim
127 words
In a distributed data processing system including a plurality of peers, a method for determining whether a peer has won a race for a system privilege, the method performed by any one peer of the plurality of peers, comprising the steps of: searching for a share control file in a predetermined location in the distributed data system, the share control file containing an address of a master peer which has the system privilege; responsive to the absence of the share control file, creating a share control file in the predetermined location, the share control file containing an address of the peer to become the master peer; placing an exclusive write lock on the share control file; and, maintaining the exclusive write lock on the share control file.
Claim 3
Dependent Claim
77 words
The method as recited in claim 1 which further comprises a method performed by peer for determining whether the second peer has won the race for the system privilege, comprising the steps of: searching for the share control file in the predetermined location in the distributed data system; responsive to finding the share control file, reading the share control file for the address of the master peer; and, negotiating with the master peer for the system privilege.
Claim 4
Dependent Claim
19 words
The method as recited in claim 2 wherein the system privilege is to control access to a common resource.
Claim 5
Dependent Claim
17 words
The method as recited in claim 2 wherein the system privilege is to perform a system process.
Claim 6
Dependent Claim
20 words
The method as recited in claim 2 wherein the predetermined location is a logical location in a distributed file system.
Claim 7
Dependent Claim
29 words
The method as recited in claim 2 wherein the plurality of peers is a plurality of system processors in individual computer systems coupled together by means of a network.
Claim 8
Dependent Claim
26 words
The method as recited in claim 2 wherein the plurality of peers is a plurality of peer applications operating on different processors in the distributed system.
Claim 9
Dependent Claim
34 words
The method as recited in claim 2 coupled together by means of a network wherein the plurality of peers is a replicated data object comprising a master replica and a plurality of shadow replicas.
Claim 10
Dependent Claim
45 words
The method as recited in claim 2 which further comprises the steps of: registering a set of the plurality of peers with the master peer as shadow peers, the shadow peers having priority in the order in which they were registered with the master peer.
Claim 11
Dependent Claim
119 words
In a distributed data processing system having a plurality of peers, a system for determining whether a first peer has won a race for a system privilege, each peer comprising: means for searching for a share control file in a predetermined location in the distributed data system, the share control file containing an address of a master peer which has the system privilege; means responsive to the absence of the share control file, for creating a share control file in the predetermined location, the share control file created in an exclusive write lock mode and containing an address of the peer to become the master peer; and, means for maintaining the exclusive write lock on the share control file.
Claim 12
Dependent Claim
119 words
In a distributed data processing system having a plurality of peers, a system for determining whether a first peer has won a race for a system privilege, each peer comprising: means for searching for a share control file in a predetermined location in the distributed data system, the share control file containing an address of a master peer which has the system privilege; means responsive to the absence of the share control file, for creating a share control file in the predetermined location, the share control file created in an exclusive write lock mode and containing an address of the peer to become the master peer; and, means for maintaining the exclusive write lock on the share control file.
Claim 13
Dependent Claim
81 words
The system as recited in claim 10 which further comprises a means included within a second peer for determining whether the second peer has won the race for the system privilege comprising: means for searching for the share control file in the predetermined location with a second peer; means responsive to finding the share control file, for reading the share control file for the address of the first peer; and, means for negotiating with the master peer for the system privilege.
Claim 14
Dependent Claim
19 words
The system as recited in claim 11 wherein the system privilege is to control access to a common resource.
Claim 15
Dependent Claim
17 words
The system as recited in claim 11 wherein the system privilege is to perform a system process.
Claim 16
Dependent Claim
19 words
The system as recited in claim 11 wherein the predetermined location is a logical location in a file system.
Claim 17
Dependent Claim
29 words
The system as recited in claim 11 wherein the plurality of peers is a plurality of system processors in individual computer systems coupled together by means of a network.
Claim 18
Dependent Claim
26 words
The system as recited in claim 11 wherein the plurality of peers is a plurality of peer applications operating on different processors in the distributed system.
Claim 19
Dependent Claim
27 words
The system as recited in claim 11 wherein the plurality of peers is a replicated data object comprising a master replica and a plurality of shadow replicas.
Claim 20
Dependent Claim
44 words
The system as recited in claim 11 which further comprises: means for registering a set of the plurality of peers with the master peer as shadow peers, the shadow peers having priority in the order in which they were registered with the master peer.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-11-20 | 1999-05-22 | 1999-11-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-11-20 | 2003-05-22 | 2003-11-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-11-20 | 2007-05-22 | 2007-11-21 | $7700.00 | Window Closed / Lapsed |