Version: 2021.3
LanguageEnglish
  • C#

IJob

interface in Unity.Jobs

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Description

Use IJob to schedule a single job that runs in parallel to other jobs and the main thread.

When a job is scheduled, the job's Execute method is invoked on a worker thread. You can use the returned JobHandle to make sure that the job has completed. It can also be passed to other jobs as a dependency, therefore ensuring the jobs are executed one after another on the worker threads.

Additional resources: IJobForExtensions.Schedule

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

class ApplyVelocitySample : MonoBehaviour { struct VelocityJob : IJob { // Jobs declare all data that will be accessed in the job // By declaring it as read only, multiple jobs are allowed to access the data in parallel [ReadOnly] public NativeArray<Vector3> velocity;

// By default containers are assumed to be read & write public NativeArray<Vector3> position;

// Delta time must be copied to the job since jobs generally don't have concept of a frame. // The main thread waits for the job on the same frame or the next frame, but the job should // perform work in a deterministic and independent way when running on worker threads. public float deltaTime;

// The code actually running on the job public void Execute() { // Move the positions based on delta time and velocity for (var i = 0; i < position.Length; i++) position[i] = position[i] + velocity[i] * deltaTime; } }

public void Update() { var position = new NativeArray<Vector3>(500, Allocator.Persistent);

var velocity = new NativeArray<Vector3>(500, Allocator.Persistent); for (var i = 0; i < velocity.Length; i++) velocity[i] = new Vector3(0, 10, 0);

// Initialize the job data var job = new VelocityJob() { deltaTime = Time.deltaTime, position = position, velocity = velocity };

// Schedule the job, returns the JobHandle which can be waited upon later on JobHandle jobHandle = job.Schedule();

// Ensure the job has completed // It is not recommended to Complete a job immediately, // since that gives you no actual parallelism. // You optimally want to schedule a job early in a frame and then wait for it later in the frame. jobHandle.Complete();

Debug.Log(job.position[0]);

// Native arrays must be disposed manually position.Dispose(); velocity.Dispose(); } }

Public Methods

ExecuteImplement this method to perform work on a worker thread.