Difference between revisions of "User:Cmpxchg"
m (fixed case-sensitivity) |
|||
| Line 2: | Line 2: | ||
|Nickname=cmpxchg | |Nickname=cmpxchg | ||
|Memberstatus=lurker | |Memberstatus=lurker | ||
| − | |Project= | + | |Project=UsbTinyIsp |
}} | }} | ||
CMPXCHG | 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). | 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). | ||
Revision as of 16:59, 17 December 2012
| TechInc Member | |
|---|---|
| nickname | cmpxchg |
| Memberstatus | lurker |
| 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).
