How to ensure async subprocess ends with Julia?

General Usage
1

Suppose I do something like this

proc = open(`long_running_command`)

How can I ensure that the process exits when Julia does?

If I just open it, the process will outlive Julia.

2

Is the process something you can communicate with to signal it should shut down itself, or are you looking to just kill it?

3

Just need to kill it.

The process starts a webserver that I send requests to, but doesn’t have any state that requires it to shut down gracefully.

Something like @at_julia_end kill(proc) would be great if @at_julia_end registers the argument to be run at shutdown

4

Either of these should work:

help?> atexit
search: atexit CapturedException InvalidStateException

  atexit(f)

  Register a zero-argument function f() to be called at process exit. atexit() hooks are called in last in first out (LIFO) order and run before object finalizers.

help?> finalizer
search: finalizer UndefInitializer finalize

  finalizer(f, x)

  Register a function f(x) to be called when there are no program-accessible references to x, and return x. The type of x must be a mutable struct, otherwise the behavior of this function is unpredictable.

You’d have to register a function that’s manually killing the process you created though.

1 Like
5

Excellent, thank you!