UnsafeAtomics

This package implements atomic operations for the Julia AtomicTypes( Float16,Float32,Float64,Int128,Int16,Int32,Int64,Int8,UInt128,UInt16,UInt32,UInt64,UInt8) without requiring to wrap them in a Atomic type. This allows atomic operations to be operated on a Vector without the extra indirection of a Vector{Atomic}.

UnsafeAtomics currently supports only operations on values that are in an Array{T:<AtomicTypes}.

Getting Started

export JULIA_NUM_THREADS=8
julia -e 'Pkg.clone("git@github.com:jpfairbanks/UnsafeAtomics.jl.git")'

Usage

n = 10
a = ones(Int64, n)
# this will ensure correctness
@threads for i in 1:1000n
       unsafe_atomic_add!(a, mod(div(i,n), n)+1, 1)
end
b = ones(Int64, n)
# this will give nondeterministic output
@threads for i in 1:1000n
       b[mod(div(i,n), n)+1] += 1
end
# if concurrently executed JULIA_NUM_THREADS > 1
# a != b