Warning: macos 10.12.* bug with SharedArray: shm_open() failed

The following program triggers a bug in macos 10.12.*, but not in 10.13.* :

(nprocs()>1) || addprocs(1)

function sharedarray_parallel_sum()
    sa = SharedArray{Float64}(5)
    @sync @parallel for i=1:5; sa[i] = timingfun(); end#for

@everywhere function timingfun();  return sqrt(2.0); end;

println("Number of Processors: $(nprocs()).")

## works with 100, but dies with 1000
for i=1:1_000; sharedarray_parallel_sum(); end

the precise bug is

Number of Processors: 2.
ERROR: LoadError: On worker 2:
SystemError: shm_open() failed for /jl047505QBT91bdhwS4cz86EgGYm: Too many open files
_link_pipe at /Applications/Julia-0.6.app/Contents/Resources/julia/lib/julia/sys.dylib:?

I have run it up to 100_000 on 10.13.*, and it does not trigger this bug.

Any updates on this issue, a work around o something?. I hit the same problem. In my case sometimes works for 100, but for 200 definitely fails. And I am using MacOs 10.14.2

Never mind. I just called * finalize * once the SharedArray is not longer needed, and it works just fine.

No. Sometimes works other don’t. The minimal example that I’m using is the following.

Late reply, but might be relevant.

I recently had a similar error in Linux. What I found that there is a limit on the number of files you can create at a time in an operating system. And a shared array is like “creating a new file” in the memory.

Therefore, we can have a certain number of shared arrays at a time. I suggest rather than creating many small-sized shared arrays, create a few big-sized shared arrays.