FazBrowse GitHub Viewer | Trending |
URL:
| Home
Tools: [Download Repo ZIP]   [Original HTTPS Page]

GH-125174: Mark objects as statically allocated. by markshannon · Pull Request #127797 · python/cpython · GitHub

  1. python
  2. cpython

Repository navigation

GH-125174: Mark objects as statically allocated. - #127797

Merged
markshannon merged 11 commits into
python:mainfrom
faster-cpython:refcnt-with-flags
Dec 11, 2024
ConversationCommits (11)ChecksFiles changed
Merged

GH-125174: Mark objects as statically allocated.#127797
markshannon merged 11 commits into
python:mainfrom
faster-cpython:refcnt-with-flags

Conversation

markshannon commented Dec 10, 2024 •
edited by bedevere-app Bot
Loading

Copy link
Copy Markdown
Member

This PR is a follow up to #125251 which made checking for immortal objects more robust.

This adds the ability to check whether objects are statically allocated or not, which should assist finalization and safety checks.

bedevere-app Bot mentioned this pull request Dec 10, 2024
Closed
ericsnowcurrently reviewed Dec 10, 2024
View reviewed changes

ericsnowcurrently left a comment

Copy link
Copy Markdown
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Choose a reason Spam Abuse Off Topic Outdated Duplicate Resolved Low Quality

Mostly LGTM. I've left a couple of minor comments. This will be a nice improvement.

Comment thread Include/refcount.h

ZeroIntensity commented Dec 11, 2024

Copy link
Copy Markdown
Member

Out of curiosity, how disruptive is adding a new field to the object structure?

markshannon commented Dec 11, 2024

Copy link
Copy Markdown
Member Author

Out of curiosity, how disruptive is adding a new field to the object structure?

It doesn't change the size of the PyObject struct or the offsets of ob_refcnt and ob_type.
Changing any of those would be very disruptive.

ericsnowcurrently approved these changes Dec 11, 2024
View reviewed changes

ericsnowcurrently left a comment

Copy link
Copy Markdown
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Choose a reason Spam Abuse Off Topic Outdated Duplicate Resolved Low Quality

LGTM

markshannon merged commit bc262de into python:main Dec 11, 2024

AlexWaygood commented Dec 11, 2024

Copy link
Copy Markdown
Member

This appears to be causing lots of compiler warnings on Windows. Here's what the "Files changed tab looks like on this PR:

These warnings are now showing up on the "files changed" tab on every PR

markshannon mentioned this pull request Dec 12, 2024
Merged
encukou reviewed Dec 12, 2024
View reviewed changes
Comment thread Include/refcount.h
#if SIZEOF_VOID_P > 4
/* If an object has been freed, it will have a negative full refcnt
* If it has not it been freed, will have a very large refcnt */
if (op->ob_refcnt_full <= 0 || op->ob_refcnt > (UINT32_MAX - (1<<20))) {

encukou Dec 12, 2024

Copy link
Copy Markdown
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Choose a reason Spam Abuse Off Topic Outdated Duplicate Resolved Low Quality

Apparently UINT32_MAX is not defined in all builds, so this breaks a buildbot.

markshannon Dec 12, 2024

Copy link
Copy Markdown
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Choose a reason Spam Abuse Off Topic Outdated Duplicate Resolved Low Quality

We use UINT32_MAX all over the place, so it must be defined. Maybe we're missing a #include somewhere.

markshannon Dec 12, 2024

Copy link
Copy Markdown
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Choose a reason Spam Abuse Off Topic Outdated Duplicate Resolved Low Quality

Looks like it's a C++ build that failing, which might explain it

markshannon Dec 12, 2024

Copy link
Copy Markdown
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Choose a reason Spam Abuse Off Topic Outdated Duplicate Resolved Low Quality

#127863

mpage mentioned this pull request Dec 12, 2024
Closed
ZeroIntensity mentioned this pull request Dec 18, 2024
Closed
srinivasreddy pushed a commit to srinivasreddy/cpython that referenced this pull request Jan 8, 2025
pythonGH-125174: Mark objects as statically allocated. (python#127797)
fb66075 
* Set a bit in the unused part of the refcount on 64 bit machines and the free-threaded build.

* Use the top of the refcount range on 32 bit machines
markshannon deleted the refcnt-with-flags branch January 10, 2025 16:23
willy-b added a commit to willy-b/cpython-fork-for-sending-documentation-fixes that referenced this pull request Sep 23, 2026
pythonGH-157724 - more GC documentation cleanup
b15b577 
- Replace "pad" field with "ob_flags":
  At python@bc262de#diff-87272721a5cf1cd9915d6f503f6a7bbefa2f26c935c7ce83ca78706afd0ad05aR155
  it seems _padding was replaced with ob_flags as part of python#127797

- Add backticks around some new mentions of flag and field names to be consistent in styling
This was referenced Sep 23, 2026
Open
Open
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters
Show hidden characters
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Reviewers

encukou encukou left review comments
ericsnowcurrently ericsnowcurrently approved these changes

Assignees

No one assigned

Labels

skip news

Projects

None yet

Milestone

No milestone

Development

Successfully merging this pull request may close these issues.

5 participants

Back | FazBrowse Home | New Git URL