JIT Assertion failure `_POP_TOP_INT.c:119: _Py_CODEUNIT *_JIT_ENTRY(_PyInterpreterFrame *, _PyStackRef *, PyThreadState *): Assertion 'PyLong_CheckExact(PyStackRef_AsPyObjectBorrow(value))' failed`

[YuanchengJiang]

Crash report

What happened?

from concurrent.futures import ThreadPoolExecutor
from unittest import TestCase
NTHREADS = 6
BOTTOM = 0
TOP = 0xffffffffffffffff
class A:
 attr = 10**1000
class TestType(TestCase):
 def read(id0):
 for _ in range(BOTTOM, TOP):
 A.attr
 def write(id0):
 x = A.attr
 x += 1
 A.attr = x
 with ThreadPoolExecutor(NTHREADS) as pool:
 pool.submit(read, (1,))
 pool.submit(write, (1,))

python: _POP_TOP_INT.c:119: _Py_CODEUNIT *_JIT_ENTRY(_PyInterpreterFrame *, _PyStackRef *, PyThreadState *): Assertion `PyLong_CheckExact(PyStackRef_AsPyObjectBorrow(value))' failed.

CPython versions tested on:

CPython main branch

Operating systems tested on:

Linux

Output from running 'python -VV' on the command line:

No response

Linked PRs

• gh-142276: Watch attribute loads when promoting JIT constants #142303

[Fidget-Spinner]

This is a real bug. I can reproduce it too. Thank you.

[Fidget-Spinner]

Thanks again for the reproducer! This was an interesting one.