Question Check whether a C# job has been completed?

Hello,
I've been using C# job system for a while now and I had a query. I know for a case like:

Code (CSharp):

1. public struct SomeJob : Unity.Jobs.IJob
2. {
3.     public void Execute()
4.     {
5.         UnityEngine.Debug.Log("Hello world!");
6.     }
7. }

I can use

Code (CSharp):

1. public void System.Collections.IEnumerator PerformSomeJob()
2. {
3.     var job = new SomeJob();
4.     var jobHandle = Unity.Jobs.IJobExtensions.Schedule<SomeJob>(job);
5.     yield return null;
6.     yield return null;
7.     jobHandle.Complete();
8. }

to make sure that the job is completed before I access its data, but is there a way I can query whether or not the job is done? I have a system that does allow for a couple frame delay, but one frame delay would be more preferable. And I was wondering if there was a way I can query this to the job scheduler. Something like:

Code (CSharp):

1. public void System.Collections.IEnumerator PerformSomeJob()
2. {
3.     var job = new SomeJob();
4.     var jobHandle = Unity.Jobs.IJobExtensions.Schedule<SomeJob>(job);
5.  
6.     yield return null;
7.  
8.     if (jobHandle.IsDone) // <-- THIS IS WHAT I WOULD LIKE TO DO
9.     {
10.         // do something to collect the results from the job
11.         yield break;
12.     }
13.  
14.     yield return null;
15.  
16.     jobHandle.Complete();
17.     // do something to collect the results from the job
18. }

 

I don't know if you've tried this, but couldn't you just have the job change some bool value at the end, which you check?

 

The only possible ways I know to persist the modifications of any job are:
1. SharedStatic<T> - doesn't work because I have several instances of this job running at the same time
2. NativeArray<T> - doesn't work because of atomic safety handle

The only way I can think of is creating a native array of 1 byte on the main thread, pass it as a pointer to the job, disable native unsafe pointer restriction, and then read it on the main thread. I'm not sure how good an idea that is without a locking mechanism though.

 

Is what I mentioned the target use-case for this?

I did come across this through IDE auto-completion, but I was under the impression that the target use-case for this API is to check if JobHandle.Complete() has already been called, and not whether the job itself has been completed. I have not personally tried this out, but I remember discarding it a few months back because of my assumption, and didn't remember until I saw this link.

If it indeed is the target use-case (to check whether the job has been completed before calling JobHandle.Complete()), then please confirm.

 

sorry for a 5 month late reply

JobHandle.IsCompleted works fine.

If someone else finds this thread, don't forget to call JobHandle.Complete() afterwards to regain NativeArray access on main thread.