Message397741
asyncio will only keep weak references to alive tasks (in `_all_tasks`). If a user does not keep a reference to a task and the task is not currently executing or sleeping, the user may get "Task was destroyed but it is pending!".
I would suggest adding the following paragraph to `create_task()` documentation:
Python only keeps weak references to the scheduled tasks. To avoid the task being destroyed by the garbage collector while still pending, a reference to it should be kept until the task is done.
And maybe an example in case a user wants something "fire and forget"?
```python
running_tasks = set()
# [...]
task = asyncio.create_task(some_background_function())
running_tasks.add(task)
task.add_done_callback(lambda t: running_tasks.remove(t))
```
The same applies to ensure_future as it now uses create_task, so maybe a "See create_task()". |
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Date |
User |
Action |
Args |
2021-07-18 06:01:26 | bernat | set | recipients:
+ bernat, docs@python |
2021-07-18 06:01:26 | bernat | set | messageid: <1626588086.28.0.802457585502.issue44665@roundup.psfhosted.org> |
2021-07-18 06:01:26 | bernat | link | issue44665 messages |
2021-07-18 06:01:25 | bernat | create | |
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