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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Initialize/Finalize Python multiple time and import datetime each time lead to a memory corruption","articleBody":"# Crash report\r\n\r\n### What happened?\r\n\r\nExample on Windows (debug build):\r\n\r\n```py\r\n# Taken from _ctypes issue: #116467\r\nimport subprocess\r\nprogram = r\"PCbuild\\amd64\\_testembed_d.exe\"\r\ncmd = [program, \"test_repeated_init_exec\", \"import datetime\"]   # or _datetime\r\n\r\nfor i in range(1, 11):\r\n    print(f\"   == Process #{i} ===\")\r\n    proc = subprocess.run(cmd)\r\n    exitcode = proc.returncode\r\n    print(f\"=\u003e exitcode {exitcode}\")\r\n    if exitcode:\r\n        break\r\n    print()\r\n```\r\n\r\n\r\nOutput (7bbce383fa207ad83a6221bf70678c75c3c92142: CI failures with a similar test):\r\n```\r\nRunning Debug|x64 interpreter...\r\n   == Process #1 ===\r\n--- Loop #1 ---\r\n--- Loop #2 ---\r\nAssertion failed: PyUnicode_CheckExact(ep_key), file C:\\a\\Objects\\dictobject.c, line 1119\r\n=\u003e exitcode 3\r\n```\r\n\r\n\r\nIt is an expected error on a debug build, which comes form [`_PyUnicode_ClearInterned()`](https://github.com/python/cpython/blob/ea2c0016502472aa8baa3149050ada776d17a009/Objects/unicodeobject.c#L14679) in `unicodeobject.c` of the commit ea2c001:\r\n\r\n```c\r\nvoid\r\n_PyUnicode_ClearInterned(PyInterpreterState *interp)\r\n{\r\n    ...\r\n    /* TODO:\r\n     * Currently, the runtime is not able to guarantee that it can exit without\r\n     * allocations that carry over to a future initialization of Python within\r\n     * the same process. i.e:\r\n     *   ./python -X showrefcount -c 'import itertools'\r\n     *   [237 refs, 237 blocks]\r\n     *\r\n     * Therefore, this should remain disabled for until there is a strict guarantee\r\n     * that no memory will be left after `Py_Finalize`.\r\n     */\r\n#ifdef Py_DEBUG\r\n    ...\r\n```\r\nCurrently, release builds avoid the `datetime` crash by leaking all interned strings.  Both the crash and the leak should be fixed before shipping 3.13 final.\r\n\r\n\u003cbr\u003e\r\n\r\nThis dedicated issue is requested in:\r\n\r\n* #103092\r\n\r\n### CPython versions tested on:\r\n\r\n3.12, CPython main branch\r\n\r\n### Operating systems tested on:\r\n\r\nLinux, macOS, Windows\r\n\r\n\u003c!-- gh-linked-prs --\u003e\r\n### Linked PRs\r\n* gh-118531\r\n\u003c!-- /gh-linked-prs --\u003e\r\n","author":{"url":"https://github.com/neonene","@type":"Person","name":"neonene"},"datePublished":"2024-05-05T20:00:26.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":10},"url":"https://github.com/118608/cpython/issues/118608"}