摘要:
A fast crash safe method and apparatus for enforcing mutually exclusive access to shared resources in a computer system through the use of semaphores. The acquisition and release of the semaphores is implemented at the user process level. An overestimate and underestimate of semaphore ownership are maintained in memory by library provided semaphore acquisition and release code. A cleanup routine reconciles the overestimate and underestimate to determine the ownership status of the semaphores.
摘要:
Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for providing geographically relevant search results. In one aspect, a method includes receiving a geotoken for a resource. The geotoken can be a resource token that references a geographic location. A semantic geotoken can be selected using the received geotoken. The semantic geotoken is a standardized representation of the geographic location that includes one or more location-specific terms. The semantic geotoken is stored with a reference to the resource. Neighboring locations for the geographic location are determined. The neighboring locations are within a predetermined distance of the geographic location. Semantic geotokens for the neighboring locations are selected and stored with the reference to the resource. Data specifying the semantic geotokens and the reference to the resource are provided.