Copy an atomic variable as a regular variable

General Usage
, ,
1

Hello,

I am trying to read the value of an atomic (shared) variable as a local (on the current thread) variable.

Here is what I tried.

julia> a = Threads.Atomic{Int}(2)
Base.Threads.Atomic{Int64}(2)

julia> b = convert(Int, a)
ERROR: MethodError: Cannot `convert` an object of type Base.Threads.Atomic{Int64} to an object of type Int64
Closest candidates are:
  convert(::Type{T}, ::T) where T<:Number at number.jl:6
  convert(::Type{T}, ::Number) where T<:Number at number.jl:7
  convert(::Type{T}, ::Base.TwicePrecision) where T<:Number at twiceprecision.jl:250
  ...
Stacktrace:
 [1] top-level scope

Do you know how I can snapshot the shared variable to use it locally on the Thread ?
For more information, I try to do something like this.

Have a nice day

2

Code:

a = Threads.Atomic{Int}(2)
b = a[]

Output:

2

Code:

using Printf
@show Threads.nthreads()
@show a = Threads.Atomic{Int}(99)
Threads.@threads for i in 1:10
    a[] = i
    @printf "(id: %2d)  i = %2d,  a[] = %2d\n" Threads.threadid() i a[]
    b = a[]
    @printf "(id: %2d)  i = %2d,  b = %2d\n" Threads.threadid() i b
end

Output:

Threads.nthreads() = 6
a = Threads.Atomic{Int}(99) = Base.Threads.Atomic{Int64}(99)
(id:  1)  i =  1,  a[] =  1
(id:  5)  i =  9,  a[] =  9
(id:  2)  i =  3,  a[] =  3
(id:  3)  i =  5,  a[] =  5
(id:  4)  i =  7,  a[] =  7
(id:  6)  i = 10,  a[] = 10
(id:  1)  i =  1,  b =  5
(id:  5)  i =  9,  b =  5
(id:  2)  i =  3,  b =  5
(id:  3)  i =  5,  b =  5
(id:  4)  i =  7,  b =  5
(id:  6)  i = 10,  b =  5
(id:  1)  i =  2,  a[] =  2
(id:  3)  i =  6,  a[] =  6
(id:  4)  i =  8,  a[] =  8
(id:  2)  i =  4,  a[] =  4
(id:  3)  i =  6,  b =  4
(id:  4)  i =  8,  b =  4
(id:  1)  i =  2,  b =  4
(id:  2)  i =  4,  b =  4
1 Like