ReadOnlyAttribute

描述

将作业中使用的结构体成员标记为只读。

在作业中使用时，原生容器默认为读写。这意味着您无法同时安排两个引用相同容器的作业。在作业结构体中的原生容器字段中添加 ReadOnly 属性以将其标记为只读。这允许两个作业并行运行并从相同的原生容器读取数据。

其他资源：IJob，IJobParallelFor。

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

public struct MyJob : IJob
{
    [ReadOnly]
    public NativeArray<int> input;

    public NativeArray<int> output;

    public void Execute()
    {
        for (var i = 0; i < output.Length; ++i)
            output[i] = input[i];
    }
}

public class ParallelReplicator : MonoBehaviour
{
    public void OnUpdate()
    {
        const int n = 10000;
        var original = new NativeArray<int>(n, Allocator.Persistent);
        var clone1 = new NativeArray<int>(n, Allocator.Persistent);
        var clone2 = new NativeArray<int>(n, Allocator.Persistent);

        var job1 = new MyJob
        {
            input = original,
            output = clone1
        };
        var job2 = new MyJob
        {
            input = original,
            output = clone2
        };

        var jobX = new MyJob
        {
            input = original,
            output = clone2
        };

        // Run the jobs in parallel.
        var jobs = JobHandle.CombineDependencies(job1.Schedule(), job2.Schedule());

        // jobX.Schedule(); // Not allowed, throws exception because job2 is writing into clone2.

        jobs.Complete();

        jobX.Schedule().Complete(); // Allowed, because job2 has been completed by now.

        original.Dispose();
        clone1.Dispose();
        clone2.Dispose();
    }
}