The LocalAtomicObject is a very simple abstraction that is optimized to ignore the locale portion of a wide pointer (and act directly on the addr), and perform normal 64-bit atomic operations that way. It is a simple yet efficient solution. Also provided is a solution for the ABA problem that relies on CMPXCHG16B Intel instruction for Double-Word Compare-And-Swap. We require unmanaged classes; currently this will leak memory if you do not have safe memory-management solution. Originally developed during the Distributed Data Structures effort for GSoC 2017 and now continued in the Concurrent-Safe Memory Reclamation Systems effort for GSoC 2019.

Dependencies

Intel's CMPXCHG16B must be supported on your system (it is on ~99% of machines these days) for double-word compare-and-swap. As well, when you compile you must build with CHPL_LLVM set (I.E to CHPL_LLVM=llvm or CHPL_LLVM=system) as the program uses extern blocks.