Patent ID: 7539678
Filing Date: 2009-05-26
Classification: G06F,Y10S

Abstract:
1. A method of controlling access to a first data structure, the method comprising: providing a data field within a header of the first data structure stored in a computer memory, the data field containing information about the accessibility of the first data structure, the data field representing a primary lock, wherein the primary lock is configured to indicate a single state of a plurality of states at a given time by changing a plurality of bits used to quickly determine the state of the primary lock, the plurality of states comprising: in response to a first thread accessing the first data structure, changing the information about the accessibility of the first data structure in the data field to indicate that the first data structure is not accessible by indicating the identification of the first thread; and in response to an attempt to access the first data structure by a second competing thread while the first thread is accessing the first data structure: a recursion count data field that stores a counter that indicates how many times competing threads have recursively acquired the primary lock: and