[python] Ensure GIL is held during CPython API call#22402
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vepadulano merged 1 commit intoMay 27, 2026
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Test Results 22 files 22 suites 3d 12h 45m 1s ⏱️ Results for commit fc87fa7. ♻️ This comment has been updated with latest results. |
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Thank you very much for the fix!
ROOT's CPython extension defines a custom error handler that tries to use Python standard warnings when possible. In such cases, the CPython API is called and thus the GIL must be held. If the calling Python function had previously released the GIL it will result in trouble. This is the case for the TH1.Fit method which has been changed to always releasing the GIL, under the assumption that everything happening during the call happens in C++, but that's not true. This commit proposes to restore the GIL for the call to the CPython API to raise the warning.
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/backport to 6.40 |
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Preparing to backport PR #22402 to branch 6.40 requested by vepadulano |
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This PR has been backported to branch 6.40: #22408 |
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### Briefly, what does this PR introduce? Please link to any relevant presentations or discussions. This PR backports root-project/root#22402 into 6.38.02 through 6.40.00, in order to avoid failures in https://eicweb.phy.anl.gov/EIC/benchmarks/detector_benchmarks/-/jobs/7889057. ### What is the urgency of this PR? - [ ] High (please describe reason below) - [x] Medium - [ ] Low ### What kind of change does this PR introduce? - [x] Bug fix (issue: https://eicweb.phy.anl.gov/EIC/benchmarks/detector_benchmarks/-/jobs/7889057) - [ ] New feature (issue #__) - [ ] Optimization (issue #__) - [ ] Updated documentation - [ ] other: __ ### Please check if any of the following apply - [ ] This PR introduces breaking changes. Please describe changes users need to make below. - [ ] This PR changes default behavior. Please describe changes below. - [ ] AI was used in preparing this PR. Please describe usage below.
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ROOT's CPython extension defines a custom error handler that tries to use Python standard warnings when possible. In such cases, the CPython API is called and thus the GIL must be held. If the calling Python function had previously released the GIL it will result in trouble. This is the case for the TH1.Fit method which has been changed to always releasing the GIL, under the assumption that everything happening during the call happens in C++, but that's not true. This commit proposes to restore the GIL for the call to the CPython API to raise the warning.