reduction with push!! not working (in contrast to append!!)?

[mauricelanghinrichs]

Hey,

I'm currently trying to get into multi-threading and I was excited to find your package/macros to do this. So first thanks for making all this!

Following up on the odds/even floop from the docs I noticed a behaviour where I'm not sure if it's a bug or supposed to be that way. When replacing the append!! with an equivalent push!! code, the output is wrong in multi-threaded execution.

using FLoops
using BangBang
using Random

function run_append(niter; ex=ThreadedEx())
    @floop ex for i in 1:niter
        @init θ = zeros(1)
        θ .= rand()
        @reduce(θsamples = append!!(Vector{Float64}(), θ))
    end
    θsamples
end

# returns Vector{Float64} with 1000 elements as expected
run_append(1000)

function run_push(niter; ex=ThreadedEx())
    @floop ex for i in 1:niter
        @init θ = zeros(1)
        θ .= rand()
        @reduce(θsamples = push!!(Vector{Float64}(), θ[1]))
    end
    θsamples
end

# returns Vector{Any} with some 252 elements (unexpected)
run_push(1000)

# would run correctly in single-thread
run_push(1000, ex=SequentialEx())

Would be really happy to understand what's going on!
Best