Fix profiling in Python 3.10 #259
Merged
Conversation
This file contains 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 cframe member was always being initialized from the PyThreadState's root_cframe, which doesn't properly have use_tracing set, so new greenlets didn't get tracing. Here, we do exactly what CPython's ceval.c does and stack-allocate a new CFrame object in g_initialstub and copy the use_tracing value from the currently executing thread state. This seems to solve the tracing issue, but further tests are needed; none of the existing tests failed with the broken behaviour. In addition to adding an example from #256, we need to test that the use_tracing flag properly propagates up and down when a profiler is set inside a greenlet, likewise I've only been testing switch, need to test throw, and need to test several variations on calling g.run(): as a method, just a target function, an object assigned to a greenlet, etc.
This proves that propagating the tracer *upward* (to a parent greenlet) in Cpython 3.10 fails. However, 4287a40 did fix propagating it downward (to a new greenlet). Likely, propagating among sibling greenlets is also broken.
Because it's stack based, we need to store it separately.
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Outdated suggestions cannot be applied.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.
This required some additional state management and several new tests.
Fixes #256.