CAS is used for implementing synchronization primitives like semaphores and mutexes, likewise more sophisticated lock-free and wait-free algorithms. Maurice Herlihy (1991) proved that CAS can implement more of these algorithms than atomic read, write, or fetch-and-add, and assuming a fairly large amount of memory, that it can implement all of them.
Algorithms built around CAS typically read some key memory location and remember the old value. Based on that old value, they compute some new value. Then they try to swap in the new value using CAS, where the comparison checks for the location still being equal to the old value. If CAS indicates that the attempt has failed, it has to be repeated from the beginning: the location is re-read, a new value is re-computed and the CAS is tried again.
Read more about this topic: Compare-and-swap
Other articles related to "usage":
... In older Javanese usage and in modern Balinese usage, gong is used to identify an ensemble of instruments ... In contemporary central Javanese usage, the term gamelan is preferred and the term gong is reserved for the gong ageng, the largest instrument of the type, or for surrogate instruments such as ... In Balinese usage, gong refers to Gamelan Gong Kebyar ...
... "The first person we know of who made usage refer to language was Daniel Defoe, at the end of the seventeenth century" ...
... the "U", or upper-class, and "non-U" classification of linguistic usage and behaviour (see U and non-U English) — although this is something she saw as a tease and she ... frequently portrayed her as the snobbish inventor and main preserver of this usage ... of the phrase, as an example of upper-class linguistic usage ...
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