Patent ID: 7111298

Claim:
In a data-storage system having resources to be shared among processors, a method for asserting exclusive access to a resource by a first processor, said method comprising: selecting an extent of a first interval on the basis of a time required for the processors to read from and write to a location accessible to the processors; determining whether there exists a competing claim to exclusive access to said resource by another processor; posting, at the location accessible to the processors, a claim to exclusive access to said resource by said first processor; determining whether there exists a competing claim to exclusive access to said resource by another processor, following lapse of said first interval that begins with the posting of the claim; and determining whether there exists a competing claim to exclusive access to said resource by another processor, following lapse of a second interval that begins after the lapse of the first interval, wherein the second interval is selected on the basis of an expected usage time for said resource.