# How to know when a task is done?
**URL:** https://discourse.julialang.org/t/how-to-know-when-a-task-is-done/63978
**Category:** General Usage
**Tags:** question, task
**Created:** [July 3, 2021, 7:16am UTC](https://discourse.julialang.org/t/how-to-know-when-a-task-is-done/63978 "2021-07-03T07:16:11Z")
**Posts on this page:** 11
**Page:** 1
### Author:  [@singularitti](https://discourse.julialang.org/u/singularitti)
#### Post date: [July 3, 2021, 7:16am UTC](https://discourse.julialang.org/t/how-to-know-when-a-task-is-done/63978/1 "2021-07-03T07:16:11Z")
If I create a `Task` using `@async`, and want to do something (like changing some status) immediately after that task is done, how do I do that? I guess `istaskdone` can only let me check everytime manually. I don’t quite understand `notify` & `Condition`, do they just notify me, or I can run some functions?
---
### Author:  [@findmyway](https://discourse.julialang.org/u/findmyway)
#### Post date: [July 3, 2021, 7:37am UTC](https://discourse.julialang.org/t/how-to-know-when-a-task-is-done/63978/2 "2021-07-03T07:37:33Z")
You can [`wait`](https://docs.julialang.org/en/v1/base/parallel/#Base.wait) the task to finish.
---
### Author:  [@singularitti](https://discourse.julialang.org/u/singularitti)
#### Post date: [July 4, 2021, 7:20am UTC](https://discourse.julialang.org/t/how-to-know-when-a-task-is-done/63978/3 "2021-07-04T07:20:26Z")
How? I don’t want `wait` to block my following commands. What I want is scheduling a `Task` and then do my things. When the `Task` is done, it will notify me, or do more things, like writing some text to a file, etc.
---
### Author:  [@findmyway](https://discourse.julialang.org/u/findmyway)
#### Post date: [July 4, 2021, 8:03am UTC](https://discourse.julialang.org/t/how-to-know-when-a-task-is-done/63978/4 "2021-07-04T08:03:40Z")
> [@singularitti](#):
>
> I don’t want `wait` to block my following commands. What I want is scheduling a `Task` and then do my things.
Then you can simply create another `Task`, inside of which you `wait` for the previous task.
---
### Author:  [@Skoffer](https://discourse.julialang.org/u/Skoffer)
#### Post date: [July 4, 2021, 9:16am UTC](https://discourse.julialang.org/t/how-to-know-when-a-task-is-done/63978/6 "2021-07-04T09:16:40Z")
Also you can just add this command inside your task
```julia
@async begin
# commands of your original task
# do something, when previous commands are complete
end
```
---
### Author:  [@Sukera](https://discourse.julialang.org/u/Sukera)
#### Post date: [July 4, 2021, 9:18am UTC](https://discourse.julialang.org/t/how-to-know-when-a-task-is-done/63978/7 "2021-07-04T09:18:21Z")
> [@singularitti](#):
>
> When the `Task` is done, it will notify me, or do more things, like writing some text to a file, etc.
What do you mean by “notify me”?
---
### Author:  [@singularitti](https://discourse.julialang.org/u/singularitti)
#### Post date: [July 4, 2021, 5:47pm UTC](https://discourse.julialang.org/t/how-to-know-when-a-task-is-done/63978/10 "2021-07-04T17:47:48Z")
> What do you mean by “notify me”?
Sorry if I was unclear. I want a `Task` that can handle some jobs for me while not blocking what I am doing ( `@async` ). But when that `Task` is done, I can immediately know it instead of checking with `istaskdone` each time manually. Also, I may want it to change the status of the job from `Running` to `Succeeded` or `Failed` , etc. And I may also want to do some other things immediately when the `Task` is done.
You can see my code [here](https://github.com/MineralsCloud/SimpleWorkflow.jl/blob/170b2b14f920e2f338f1f393d2052d7f001f1990/src/SimpleWorkflow.jl#L91-L101). I used `@spawn` to do this, but it is not the most simple way, I think.
---
### Author:  [@jzr](https://discourse.julialang.org/u/jzr)
#### Post date: [July 4, 2021, 6:06pm UTC](https://discourse.julialang.org/t/how-to-know-when-a-task-is-done/63978/11 "2021-07-04T18:06:03Z")
Is this for use in an interactive Julia environment, or for a program to run by itself?
---
### Author:  [@singularitti](https://discourse.julialang.org/u/singularitti)
#### Post date: [July 4, 2021, 6:23pm UTC](https://discourse.julialang.org/t/how-to-know-when-a-task-is-done/63978/12 "2021-07-04T18:23:27Z")
Both. I want it to be programmable as scripts and also interactive.
---
### Author:  [@Sukera](https://discourse.julialang.org/u/Sukera)
#### Post date: [July 5, 2021, 7:39am UTC](https://discourse.julialang.org/t/how-to-know-when-a-task-is-done/63978/13 "2021-07-05T07:39:17Z")
The problem is that, even with your clarification, “notify me” is ill defined. You are not your program after all - there is no automatic message queue or notification bar or something like that, you’ll have to create something that handles finished tasks for you. This is what @findmyway meant when they mentioned you have to create another Task that handles those for you. One way to achieve that is to have each task you spawned take e.g. a Channel to put results, errors etc. into and have a number of other tasks pull results out of that channel and act according to whatever that result is (e.g. spawn new tasks, write them to a file, etc.)
If you want it to work interactively, I’d look into [ReplMaker.jl](https://juliahub.com/ui/Packages/ReplMaker/TRU6e/0.2.5). You will have to decouple the interactive part from the standalone part, else your code will probably beome a lot harder to maintain.
---
### Author:  [@kristoffer.carlsson](https://discourse.julialang.org/u/kristoffer.carlsson)
#### Post date: [July 5, 2021, 11:23am UTC](https://discourse.julialang.org/t/how-to-know-when-a-task-is-done/63978/14 "2021-07-05T11:23:16Z")
Something like
```julia
@sync begin
c = Condition()
@async begin
for i in 1:5
println("I am doing work in the background...")
sleep(0.5)
end
notify(c)
end
@async begin
wait(c)
println("I got notified")
end
end
```
with output:
```julia
I am doing work in the background...
I am doing work in the background...
I am doing work in the background...
I am doing work in the background...
I am doing work in the background...
I got notified
```
?