US 8,135,839 B1Granted

System and method for locking exclusive access to a divided resource

AssigneeAdobe Systems Incorporated

InventorsMatthew A. Wormley, John L. Farmer

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Abstract

A method of locking exclusive access to a divided computer resource that may be access by more than one different is disclosed. A computer resource that is divided into more than one piece may require exclusive access to all the individual portions before the computer resource may be used. If more than one client system attempts to access such a divided computer resource, a deadlock situation may occur. To prevent such a deadlock situation, each client that attempts to access the divided resource will issue a globally unique identifier to the divided resource. If more than one client system attempts to access portions of the same computer resource then the globally unique identifier will be used to arbitrate disputes and thus prevent deadlock.

Claims15

Dependent claims

A method of allowing access to a shared resource, said method comprising:

receiving a first request for a file in a first portion of said shared resource, said first request containing a first token value from a first client system;
receiving a second request for said file in a second portion of said shared resource, said second request containing said first token value from said first client system one of said first portion or said second portion being a primary storage location for said file and a remaining portion being a secondary storage location for said file;
performing a first comparison in said first portion of said shared resource based on more than one request being received in said first portion of said shared resource, said first comparison comparing said first token value with a second token value received from a second client system, said token value comprises a globally unique identifier value;
and
issuing a no-lock response to said second client system from said first portion of said shared resource based on said first token value comparing favorably against said second token value and issuing a lock response to said first client system from said second portion based on said first token value comparing favorably against said second token value, both said first portion and said second portion being required in order for said first client system to access said shared resource.

2 more elements

A network accessible shared resource, said network accessible shared resource comprising:

a first portion of said shared resource;
a second portion of said shared resource, both said first portion and said second portion being required in order for a client system to access said shared resource, one of said first portion or said second portion being a primary storage location for a file and a remaining portion being a secondary storage location for said file;
and
a first comparison unit in said first portion of said shared resource, said first portion of said resource receiving a first request containing a first token value from a first client system and a second request containing a second token value from a second client system, said first comparison unit performing a first comparison comparing said first token value with said second token value, said token comprises a globally unique identifier value;
said first comparison unit issuing a no-lock response to said second client system from said first portion of said shared resource based on said first token value comparing favorably against said second token value and issuing a lock response to said first client system from said second portion based on said first token value comparing favorably against said second token value.

2 more elements

A non-transitory computer-readable medium, said computer-readable medium comprising a set of instructions that, when executed by one or more processors implement a method of allowing access to a shared resource, said method comprising:

receiving a first request for a file in a first portion of said shared resource, said first request containing a first token value from a first client system;
receiving a second request for said file in a second portion of said shared resource, said second request containing said first token value from said first client system, one of said first portion or said second portion being a primary storage location for said file and a remaining portion being a secondary storage location for said file;
performing a first comparison in said first portion of said shared resource based on more than one request being received in said first portion of said shared resource, said first comparison comparing said first token value with a second token value received from a second client system, said token comprises a globally unique identifier value;
issuing a no-lock response to said second client system from said first portion of said shared resource based on said first token value comparing favorably against said second token value;
and
issuing a lock response to said first client system from said second portion based on said first token value comparing favorably against said second token value, both said first portion and said second portion being required in order for said first client system to access said shared resource.

3 more elements

Dependencies are inferred from the claim text.