 | This article includes a list of general references, but it lacks sufficient corresponding inline citations. (February 2015) |
In computer science, load-linked/store-conditional[1] (LL/SC), sometimes known as load-reserved/store-conditional[2] (LR/SC), are a pair of instructions used in multithreading to achieve synchronization. Load-link returns the current value of a memory location, while a subsequent store-conditional to the same memory location will store a new value only if no updates have occurred to that location since the load-link. Together, this implements a lock-free, atomic, read-modify-write operation.
"Load-linked" is also known as load-link,[3] load-reserved,[2] and load-locked.[citation needed]
LL/SC was originally[4] proposed by Jensen, Hagensen, and Broughton for the S-1 AAP multiprocessor[1] at Lawrence Livermore National Laboratory.
- ^ a b Cite error: The named reference
S-1was invoked but never defined (see the help page). - ^ a b Cite error: The named reference
RISCVwas invoked but never defined (see the help page). - ^ US20030217115A1, Rowlands, Joseph, "Load-linked/store conditional mechanism in a CC-NUMA system", issued 2003-11-20
- ^ Herlihy, Maurice (1993-11-01). "A methodology for implementing highly concurrent data objects". ACM Transactions on Programming Languages and Systems. 15 (5): 745–770. doi:10.1145/161468.161469. ISSN 0164-0925.