gh-106078: Convert _decimal types to heap types

[CharlieZhao95]

• Establish a global module state
• Convert _decimal types to heap types

Co-authored-by: Erlend E. Aasland erlend.aasland@protonmail.com

• Issue: Isolate the _decimal extension module #106078

[CharlieZhao95]

cc: @kumaraditya303 @erlend-aasland

[kumaraditya303]

Mostly LGTM but there are some compiler warnings to be taken care of.

[bedevere-bot]

🤖 New build scheduled with the buildbot fleet by @kumaraditya303 for commit bb4e191 🤖

If you want to schedule another build, you need to add the 🔨 test-with-buildbots label again.

[erlend-aasland]

Can you please add tests for basic type qualities:

• immutability
• disallow instantiation

[kumaraditya303]

Refleaks looks good:

0:00:00 load avg: 2.73 Run tests sequentially
0:00:00 load avg: 2.73 [1/1] test_decimal
beginning 6 repetitions
123456
......

== Tests result: SUCCESS ==

1 test OK.

Total duration: 26.0 sec
Tests result: SUCCESS

[CharlieZhao95]

I found another interesting problem while testing. The following code will causes a segmentation fault:

>>> import decimal
>>> tp = type(decimal.Context().flags)  # SignalDict type
>>> tp()  # Segmentation fault

I guess that the problem is caused by accessing the wild pointer when executing the signaldict_repr function. But this problem is not caused by this PR. I tested version Python 3.10 on Linux, and this problem exists as well. Maybe this problem is worth to open a new issue.

[serhiy-storchaka]

There are currently two test classes for the C implementation: CWhitebox and SignatureTest. None of them are suitable for new tests?

[erlend-aasland]

There are currently two test classes for the C implementation: CWhitebox and SignatureTest. None of them are suitable for new tests?

Good point; I think the added tests can fit in the CWhitebox test case.

[kumaraditya303]

I'll merge this later today after a refleak test.

[bedevere-bot]

🤖 New build scheduled with the buildbot fleet by @kumaraditya303 for commit 2f4f538 🤖

If you want to schedule another build, you need to add the 🔨 test-with-refleak-buildbots label again.

[erlend-aasland]

I'll merge this later today after a refleak test.

@kumaraditya303, let me amend the tests before merging.

[serhiy-storchaka]

It would be nice to wait until #106209¹ be merged.

Footnotes

1. Amended with correct link by Erlend ↩

[erlend-aasland]

Good job, @CharlieZhao95!

[CharlieZhao95]

Good job, @CharlieZhao95!

Thanks all! Let's move on to the next! :)