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Generator .close does not release resources #118272
Description
Bug report
Bug description:
Sending a generator .close() in Python 3.12 does not release resources used by local variables as it used to do in earlier versions of Python. Wrapping the generator content in a try: ... except GeneratorExit: pass releases the resources as expected.
The following shows the difference in space usage between wrapping the code with try-except and not.
def generator_using_a_lot_of_space():
a_big_set = set(range(10_000_000))
yield 42
g = generator_using_a_lot_of_space()
input('A <press enter>') # 13.4 MB
print(next(g))
input('B <press enter>') # 576.6 MB
g.close()
input('C <press enter>') # 576.6 MB <== space usage used to drop to 13-14 MB
def generator_using_a_lot_of_space():
a_big_set = set(range(10_000_000))
try:
yield 42
except GeneratorExit:
pass
g = generator_using_a_lot_of_space()
input('D <press enter>') # 14.6 MB
print(next(g))
input('E <press enter>') # 575.6 MB
g.close()
input('F <press enter>') # 14.6 MB <== drop in space usage as expectedThe above space measurements were done with
Python 3.12.3 (tags/v3.12.3:f6650f9, Apr 9 2024, 14:05:25) [MSC v.1938 64 bit (AMD64)] on win32
and looking at the space usage reported by the Windows 11 Task Manager.
CPython versions tested on:
3.12
Operating systems tested on:
Windows
Activity
graingert commentedon Apr 25, 2024
bisected to eb4774d using:
outputs:
should output:
passes on 3.11, fails on 3.12 and 3.13a6
pythongh-118272: Clear generator frame's locals when the generator is…
iritkatriel commentedon Apr 25, 2024
Thank you, @gsbrodal for the report, and @graingert for the investigation.
gh-118272: Clear generator frame's locals when the generator is closed (
pythongh-118272: Clear generator frame's locals when the generator is…
pythongh-118272: set stacktop to 0 before freeing contents, to avoid …
gh-118272: set stacktop to 0 before freeing contents, to avoid access…
[3.12] gh-118272: Clear generator frame's locals when the generator i…
pythongh-118272: Clear generator frame's locals when the generator is…
pythongh-118272: set stacktop to 0 before freeing contents, to avoid …
Revert "[3.12] pythongh-118272: Clear generator frame's locals when t…