[3.14] gh-136396: Include instrumentation when creating new copies of the bytecode (GH-136525) #136657
Conversation
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
…the bytecode (pythonGH-136525) Previously, we assumed that instrumentation would happen for all copies of the bytecode if the instrumentation version on the code object didn't match the per-interpreter instrumentation version. That assumption was incorrect: instrumentation will exit early if there are no new "events," even if there is an instrumentation version mismatch. To fix this, include the instrumented opcodes when creating new copies of the bytecode, rather than replacing them with their uninstrumented variants. I don't think we have to worry about races between instrumentation and creating new copies of the bytecode: instrumentation and new bytecode creation cannot happen concurrently. Instrumentation requires that either the world is stopped or the code object's per-object lock is held and new bytecode creation requires holding the code object's per-object lock. (cherry picked from commit d995922) Co-authored-by: mpage <mpage@meta.com>
This was referenced Jul 14, 2025
colesbury
approved these changes
Jul 15, 2025
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Previously, we assumed that instrumentation would happen for all copies of
the bytecode if the instrumentation version on the code object didn't match
the per-interpreter instrumentation version. That assumption was incorrect:
instrumentation will exit early if there are no new "events," even if there
is an instrumentation version mismatch.
To fix this, include the instrumented opcodes when creating new copies of
the bytecode, rather than replacing them with their uninstrumented variants.
I don't think we have to worry about races between instrumentation and creating
new copies of the bytecode: instrumentation and new bytecode creation cannot happen
concurrently. Instrumentation requires that either the world is stopped or the
code object's per-object lock is held and new bytecode creation requires holding
the code object's per-object lock.
(cherry picked from commit d995922)
Co-authored-by: mpage mpage@meta.com