Difference between revisions of "User:Cmpxchg"
| Line 1: | Line 1: | ||
{{Members | {{Members | ||
|Nickname=cmpxchg | |Nickname=cmpxchg | ||
| − | |Memberstatus= | + | |Memberstatus=board |
|Project=UsbTinyIsp | |Project=UsbTinyIsp | ||
}} | }} | ||
Revision as of 19:29, 22 March 2017
| TechInc Member | |
|---|---|
| nickname | cmpxchg |
| Memberstatus | board |
| Part of Projects | UsbTinyIsp |
CMPXCHG
In computer science, compare-and-swap (CAS) is an atomic instruction used in multithreading to achieve synchronization. It compares the contents of a memory location to a given value and, only if they are the same, modifies the contents of that memory location to a given new value. The atomicity guarantees that the new value is calculated based on up-to-date information; if the value had been updated by another thread in the meantime, the write would fail. The result of the operation must indicate whether it performed the substitution; this can be done either with a simple Boolean response (this variant is often called compare-and-set), or by returning the value read from the memory location (not the value written to it).
