AllocTest.cs

using Unity.Collections;
using Unity.Jobs;
using UnityEngine;

public class AllocTest : MonoBehaviour
{
    GetResultJob job;
    JobHandle handle;

    void Update ()
    {
        var size = Random.Range(1000, 10000);

        // 毎フレームNativeArrayを生成
        var array1 = new NativeArray<int>(size, Allocator.TempJob);
        var plusHandle = new PlusJob() { array = array1 }.Schedule(size, 64);
        job = new GetResultJob() { array = array1, result = new NativeArray<int>(1, Allocator.Temp) };
        handle = job.Schedule(plusHandle);
    }
    void LateUpdate()
    {
        handle.Complete();
        var result = job.result[0];
        job.result.Dispose(); // resultはtempなので自分で開放する

        Debug.Log(result);
    }

    [ComputeJobOptimization]
    struct PlusJob : IJobParallelFor
    {
        public NativeArray<int> array;

        public void Execute(int index)
        {
            array[index]++;
        }
    }

    [ComputeJobOptimization]
    struct GetResultJob : IJob
    {
        [DeallocateOnJobCompletion]
        [ReadOnly] public NativeArray<int> array; // arrayは自動的に開放する
        [WriteOnly] public NativeArray<int> result;

        public void Execute()
        {
            int res = 0;
            for(int i=0; i<array.Length; i++)
                res += array[i];

            result[0] = res;
        }
    }

}