fix swig ownership when assigning to struct pointer field #3139
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Summary: When faiss is called from SWIG, it is usually assumed that Python will do all the memory management, therefore assigning to a pointer in C++ should not transfer ownerhsip (default SWIG behavior). This diff fixed that. Differential Revision: D51529085
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This pull request was exported from Phabricator. Differential Revision: D51529085 |
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hopefully this will finally fix #2996 |
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@mdouze do we still need this one? |
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Even though the final assert fails since the ownership disappears, it seems like the memory does not increase. This typemap looks right to me when I test it. We can discuss on next steps. |
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Current status after discussion: ASAN does not seem to detect these Python memory leaks. There are no ASAN errors in a simple repro unit test like The destructor of IndexFlatL2 does not get called when We should introduce some Python unit test to catch these memory leaks. |
mnorris11
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Aug 29, 2024
…h#3704) Summary: Pull Request resolved: facebookresearch#3704 Background -- Issue: facebookresearch#2996 Prior attempted fix: https://github.com/facebookresearch/faiss/pull/3007/files#diff-d704f33c46a4ef2936c8cf2a66b05f1993e25e79ee5c19d4b63c4e0cf46b0a42 Partially copied from facebookresearch#3139 with an additional unit test. It is a confirmed and reproducible memory leak every time. There is a workaround. See the comments on facebookresearch#2996. Relevant SWIG docs: https://www.swig.org/Doc4.1/SWIGDocumentation.html#Typemaps_nn2 Current status -- `buck test faiss/tests:test_search_params -- test_ownership_2` Test prints: without SWIG fix: `[0.49, 0.82, 1.15, 1.39, 1.67, 1.88, 2.16, 2.36, 2.65, 2.85, 3.13, 3.34, 3.62, 3.82, 4.11, 4.31, 4.6, 4.8, 5.08, 5.28]` with SWIG fix: `[0.52, 0.7, 0.7, 0.7, 0.7, 0.7, 0.7, 0.7, 0.7, 0.7, 0.7, 0.7, 0.7, 0.71, 0.71, 0.71, 0.71, 0.71, 0.71, 0.71]` Note: This test is not ideal. Ideally we could enable ASAN to catch these memory leaks. But ASAN does not seem to catch these Python memory leaks. Example: ``` def test_ownership_3(self): d = 32 quantizer = faiss.IndexFlatL2(d) quantizer.this.own(False) ``` The above test produces no ASAN error, even though the `quantizer` object leaks. Differential Revision: D60151215
mnorris11
pushed a commit
to mnorris11/faiss
that referenced
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Aug 29, 2024
…h#3704) Summary: Pull Request resolved: facebookresearch#3704 Background -- Issue: facebookresearch#2996 Prior attempted fix: https://github.com/facebookresearch/faiss/pull/3007/files#diff-d704f33c46a4ef2936c8cf2a66b05f1993e25e79ee5c19d4b63c4e0cf46b0a42 Partially copied from facebookresearch#3139 with an additional unit test. It is a confirmed and reproducible memory leak every time. There is a workaround. See the comments on facebookresearch#2996. Relevant SWIG docs: https://www.swig.org/Doc4.1/SWIGDocumentation.html#Typemaps_nn2 Current status -- `buck test faiss/tests:test_search_params -- test_ownership_2` Test prints: without SWIG fix: `[0.49, 0.82, 1.15, 1.39, 1.67, 1.88, 2.16, 2.36, 2.65, 2.85, 3.13, 3.34, 3.62, 3.82, 4.11, 4.31, 4.6, 4.8, 5.08, 5.28]` with SWIG fix: `[0.52, 0.7, 0.7, 0.7, 0.7, 0.7, 0.7, 0.7, 0.7, 0.7, 0.7, 0.7, 0.7, 0.71, 0.71, 0.71, 0.71, 0.71, 0.71, 0.71]` Note: This test is not ideal. Ideally we could enable ASAN to catch these memory leaks. But ASAN does not seem to catch these Python memory leaks. Example: ``` def test_ownership_3(self): d = 32 quantizer = faiss.IndexFlatL2(d) quantizer.this.own(False) ``` The above test produces no ASAN error, even though the `quantizer` object leaks. Differential Revision: D61992599
mnorris11
pushed a commit
to mnorris11/faiss
that referenced
this pull request
Aug 29, 2024
…h#3810) Summary: Pull Request resolved: facebookresearch#3810 Pull Request resolved: facebookresearch#3704 Background -- Issue: facebookresearch#2996 Prior attempted fix: https://github.com/facebookresearch/faiss/pull/3007/files#diff-d704f33c46a4ef2936c8cf2a66b05f1993e25e79ee5c19d4b63c4e0cf46b0a42 Partially copied from facebookresearch#3139 with an additional unit test. It is a confirmed and reproducible memory leak every time. There is a workaround. See the comments on facebookresearch#2996. Relevant SWIG docs: https://www.swig.org/Doc4.1/SWIGDocumentation.html#Typemaps_nn2 Current status -- `buck test faiss/tests:test_search_params -- test_ownership_2` Test prints: without SWIG fix: `[0.49, 0.82, 1.15, 1.39, 1.67, 1.88, 2.16, 2.36, 2.65, 2.85, 3.13, 3.34, 3.62, 3.82, 4.11, 4.31, 4.6, 4.8, 5.08, 5.28]` with SWIG fix: `[0.52, 0.7, 0.7, 0.7, 0.7, 0.7, 0.7, 0.7, 0.7, 0.7, 0.7, 0.7, 0.7, 0.71, 0.71, 0.71, 0.71, 0.71, 0.71, 0.71]` Note: This test is not ideal. Ideally we could enable ASAN to catch these memory leaks. But ASAN does not seem to catch these Python memory leaks. Example: ``` def test_ownership_3(self): d = 32 quantizer = faiss.IndexFlatL2(d) quantizer.this.own(False) ``` The above test produces no ASAN error, even though the `quantizer` object leaks. Differential Revision: D61992599
mnorris11
pushed a commit
to mnorris11/faiss
that referenced
this pull request
Sep 12, 2024
…h#3810) Summary: Pull Request resolved: facebookresearch#3810 Pull Request resolved: facebookresearch#3704 Background -- Issue: facebookresearch#2996 Prior attempted fix: https://github.com/facebookresearch/faiss/pull/3007/files#diff-d704f33c46a4ef2936c8cf2a66b05f1993e25e79ee5c19d4b63c4e0cf46b0a42 Partially copied from facebookresearch#3139 with an additional unit test. It is a confirmed and reproducible memory leak every time. There is a workaround. See the comments on facebookresearch#2996. Relevant SWIG docs: https://www.swig.org/Doc4.1/SWIGDocumentation.html#Typemaps_nn2 Current status -- `buck test faiss/tests:test_search_params -- test_ownership_2` Test prints: without SWIG fix: `[0.49, 0.82, 1.15, 1.39, 1.67, 1.88, 2.16, 2.36, 2.65, 2.85, 3.13, 3.34, 3.62, 3.82, 4.11, 4.31, 4.6, 4.8, 5.08, 5.28]` with SWIG fix: `[0.52, 0.7, 0.7, 0.7, 0.7, 0.7, 0.7, 0.7, 0.7, 0.7, 0.7, 0.7, 0.7, 0.71, 0.71, 0.71, 0.71, 0.71, 0.71, 0.71]` Note: This test is not ideal. Ideally we could enable ASAN to catch these memory leaks. But ASAN does not seem to catch these Python memory leaks. Example: ``` def test_ownership_3(self): d = 32 quantizer = faiss.IndexFlatL2(d) quantizer.this.own(False) ``` The above test produces no ASAN error, even though the `quantizer` object leaks. Why change HNSW test? -- This fix causes the HNSW test to fail with heap-use-after-free. This is because the index.storage.get_distance_computer() somehow gets freed during clone_index, but only when reassigning to the same variable like `index.storage = clone(index.storage)`. I checked in https://fburl.com/code/qw6fznjt, and it is non-null before returning on the CPP side. After adding the temp variable, I also had to set `index.own_fields = False`, otherwise we get a heap-use-after-free again due to it being deleted already. Differential Revision: D61992599
mnorris11
pushed a commit
to mnorris11/faiss
that referenced
this pull request
Sep 12, 2024
…h#3810) Summary: Pull Request resolved: facebookresearch#3810 Pull Request resolved: facebookresearch#3704 Background -- Issue: facebookresearch#2996 Prior attempted fix: https://github.com/facebookresearch/faiss/pull/3007/files#diff-d704f33c46a4ef2936c8cf2a66b05f1993e25e79ee5c19d4b63c4e0cf46b0a42 Partially copied from facebookresearch#3139 with an additional unit test. It is a confirmed and reproducible memory leak every time. There is a workaround. See the comments on facebookresearch#2996. Relevant SWIG docs: https://www.swig.org/Doc4.1/SWIGDocumentation.html#Typemaps_nn2 Current status -- `buck test faiss/tests:test_search_params -- test_ownership_2` Test prints: without SWIG fix: `[0.49, 0.82, 1.15, 1.39, 1.67, 1.88, 2.16, 2.36, 2.65, 2.85, 3.13, 3.34, 3.62, 3.82, 4.11, 4.31, 4.6, 4.8, 5.08, 5.28]` with SWIG fix: `[0.52, 0.7, 0.7, 0.7, 0.7, 0.7, 0.7, 0.7, 0.7, 0.7, 0.7, 0.7, 0.7, 0.71, 0.71, 0.71, 0.71, 0.71, 0.71, 0.71]` Note: This test is not ideal. Ideally we could enable ASAN to catch these memory leaks. But ASAN does not seem to catch these Python memory leaks. Example: ``` def test_ownership_3(self): d = 32 quantizer = faiss.IndexFlatL2(d) quantizer.this.own(False) ``` The above test produces no ASAN error, even though the `quantizer` object leaks. Why change HNSW test? -- This fix causes the HNSW test to fail with heap-use-after-free. This is because the index.storage.get_distance_computer() somehow gets freed during clone_index, but only when reassigning to the same variable like `index.storage = clone(index.storage)`. I checked in https://fburl.com/code/qw6fznjt, and it is non-null before returning on the CPP side. After adding the temp variable, I also had to set `index.own_fields = False`, otherwise we get a heap-use-after-free again due to it being deleted already. Differential Revision: D61992599
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Summary: When faiss is called from SWIG, it is usually assumed that Python will do all the memory management, therefore assigning to a pointer in C++ should not transfer ownerhsip (default SWIG behavior). This diff fixed that.
Differential Revision: D51529085