__del__ magic method can't access class properties

[jvrdnd]

What is the problem?

Class properties cannot be accessed within the __del__ method.

Exception ignored in: <function MyClass.__del__ at 0x7f070cbc5e50>
Traceback (most recent call last):
  File "example.py", line 11, in __del__
AttributeError: 'ActorClass(MyClass)' object has no attribute 'x'

Running Ubuntu 20.04, Python 3.8, Ray 1.1.

Reproduction (REQUIRED)

import ray

ray.init()

@ray.remote
class MyClass(object):
  def __init__(self):
    self.x = 0

  def __del__(self):
    print(self.x)

c = MyClass.remote()
del c

This can be fixed by creating a method within the class e.g. destroy and calling that explicitly before del but this should work within the __del__ method too?

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[Suke0811]

Hi, any workaround or fix for this? This bug still exists and is a bit of an issue cause I cannot do a close operation. Thanks!

[rkooo567]

We will triage this again. I think this could be a pretty common usability issue (although there's workaround). Are there other people who also had this issue?

[Suke0811]

Hi, thanks for that!
I have this issue exists with Ray 1.12.1 on Ubuntu 20.04 and Windows 11.
Currently, as a workaround, I'm catching signals and exceptions to explicitly check if the program is terminated abnormally. However, some situations are cannot be handled well such as process kill in cross-platform environments.
Anyways, it'll be much appreciated if del is functional since it'll only require a single line code as opposed to handling various termination scenarios.

[zhe-thoughts]

(Context: I'm doing a round of cleanup of waiting-for-triage issues)

@jjyao @rkooo567 Do you think this should be P1 or P2? For now I'm putting on Core Backlog and assigning to myself

[rkooo567]

I think it's P2. But we better fix it someday..