GitHub

Getting Started

This page covers the minimum path to install Parables, build a small DAG, and run it safely.

Installation

import Pkg
Pkg.add("Parables")

For local development in this repository:

import Pkg
Pkg.develop(path=".")

First DAG

using Parables

obj = Ref(0)

dag = Parables.@dag begin
    Parables.@spawn Parables.@task "init" begin
        Parables.@accesses begin
            (obj, Write(), Whole())
        end
        obj[] = 1
    end

    Parables.@spawn Parables.@task "bump" begin
        Parables.@accesses begin
            (obj, ReadWrite(), Whole())
        end
        obj[] += 1
    end

    Parables.@spawn Parables.@task "read" begin
        Parables.@accesses begin
            (obj, Read(), Whole())
        end
        println("value = ", obj[])
    end
end

print_dag(dag)
execute_serial!(dag)

Expected output includes value = 2.

Then Run On Threads

execute_threads!(dag)

Set Julia thread count before startup, for example:

JULIA_NUM_THREADS=8 julia

Common first checks

  • If behavior is unexpected, run execute_serial! first.
  • Use print_dag(dag) to inspect inferred dependencies.
  • Verify @access/@accesses declarations match what task code actually touches.

Next Steps