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Created on 2018-07-07 17:11 by serhiy.storchaka, last changed 2022-04-11 14:59 by admin. This issue is now closed.
| Pull Requests | |||
|---|---|---|---|
| URL | Status | Linked | Edit |
| PR 8159 | merged | serhiy.storchaka, 2018-07-07 17:21 | |
| PR 8197 | merged | miss-islington, 2018-07-09 12:41 | |
| PR 8198 | merged | serhiy.storchaka, 2018-07-09 12:51 | |
| Messages (5) | |||
|---|---|---|---|
| msg321224 - (view) | Author: Serhiy Storchaka (serhiy.storchaka) *  |
Date: 2018-07-07 17:11 | |
The bytecode generated for "with open()":
with open(path) as file:
data = file.read()
1 0 LOAD_NAME 0 (open)
2 LOAD_NAME 1 (path)
4 CALL_FUNCTION 1
6 SETUP_WITH 14 (to 22)
8 STORE_NAME 2 (file)
2 10 LOAD_NAME 2 (file)
12 LOAD_METHOD 3 (read)
14 CALL_METHOD 0
16 STORE_NAME 4 (data)
18 POP_BLOCK
20 BEGIN_FINALLY
>> 22 WITH_CLEANUP_START
24 WITH_CLEANUP_FINISH
26 END_FINALLY
28 LOAD_CONST 0 (None)
30 RETURN_VALUE
The execution can be interrupted by Ctrl-C between calling open() and entering the 'with' block. In this case the file object will be created, but its __enter__ and __exit__ methods will be not executed. As a result it will be closed after disappearing a reference to it and a ResourceWarning will be emitted.
The solution is disabling interruption before the SETUP_WITH opcode. It is already disabled before SETUP_FINALLY and YIELD_FROM. It is worth to disable it before BEFORE_ASYNC_WITH for consistency although I don't have examples for it.
See also issue29988.
|
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| msg321288 - (view) | Author: Serhiy Storchaka (serhiy.storchaka) * |
Date: 2018-07-08 20:07 | |
Maybe it is worth to disable interrupting before more opcodes. For example for fixing a problem with the contextlib.nullcontext example (issue34067) we need to disable interrupting before STORE_FAST, LOAD_FAST and JUMP_FORWARD. |
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| msg321314 - (view) | Author: Alyssa Coghlan (ncoghlan) * |
Date: 2018-07-09 12:40 | |
New changeset 3f4d90d4d72921f16babd3f52d7df804916af224 by Nick Coghlan (Serhiy Storchaka) in branch 'master': bpo-34066: Disabled interruption before SETUP_WITH and BEFORE_ASYNC_WITH. (GH-8159) https://github.com/python/cpython/commit/3f4d90d4d72921f16babd3f52d7df804916af224 |
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| msg321316 - (view) | Author: miss-islington (miss-islington) | Date: 2018-07-09 13:31 | |
New changeset f5197ddfd0f2c5da848af57196448810bd18bb82 by Miss Islington (bot) in branch '3.7': bpo-34066: Disabled interruption before SETUP_WITH and BEFORE_ASYNC_WITH. (GH-8159) https://github.com/python/cpython/commit/f5197ddfd0f2c5da848af57196448810bd18bb82 |
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| msg321328 - (view) | Author: Serhiy Storchaka (serhiy.storchaka) * |
Date: 2018-07-09 16:02 | |
New changeset eeaae26ce5abce56292330c29459337d6bd57aaf by Serhiy Storchaka in branch '3.6': [3.6] bpo-34066: Disabled interruption before SETUP_WITH and BEFORE_ASYNC_WITH. (GH-8159) (GH-8198) https://github.com/python/cpython/commit/eeaae26ce5abce56292330c29459337d6bd57aaf |
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| History | |||
|---|---|---|---|
| Date | User | Action | Args |
| 2022-04-11 14:59:02 | admin | set | github: 78247 |
| 2018-07-13 16:19:58 | jwilk | set | nosy:
+ jwilk |
| 2018-07-09 16:03:41 | serhiy.storchaka | set | status: open -> closed resolution: fixed stage: patch review -> resolved |
| 2018-07-09 16:02:28 | serhiy.storchaka | set | messages: + msg321328 |
| 2018-07-09 13:31:07 | miss-islington | set | nosy:
+ miss-islington messages: + msg321316 |
| 2018-07-09 12:51:37 | serhiy.storchaka | set | pull_requests: + pull_request7750 |
| 2018-07-09 12:41:28 | miss-islington | set | pull_requests: + pull_request7749 |
| 2018-07-09 12:40:17 | ncoghlan | set | messages: + msg321314 |
| 2018-07-08 20:07:04 | serhiy.storchaka | set | messages: + msg321288 |
| 2018-07-07 17:21:22 | serhiy.storchaka | set | keywords:
+ patch stage: patch review pull_requests: + pull_request7723 |
| 2018-07-07 17:11:52 | serhiy.storchaka | create | |