8000 [3.13] gh-128717: Stop-the-world when setting the recursion limit (GH… · python/cpython@1ec36a6 · GitHub
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[3.13] gh-128717: Stop-the-world when setting the recursion limit (GH-128741) (#128757)
[3.13] gh-128717: Stop-the-world when setting the recursion limit (GH-128741) (cherry picked from commit f6c61bf) Co-authored-by: Peter Bierma <zintensitydev@gmail.com>
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‎Lib/test/test_sys.py

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@@ -362,6 +362,36 @@ def test_setrecursionlimit_to_depth(self):
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finally:
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sys.setrecursionlimit(old_limit)
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@unittest.skipUnless(support.Py_GIL_DISABLED, "only meaningful if the GIL is disabled")
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@threading_helper.requires_working_threading()
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def test_racing_recursion_limit(self):
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from threading import Thread
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def something_recursive():
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def count(n):
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if n > 0:
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return count(n - 1) + 1
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return 0
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count(50)
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def set_recursion_limit():
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for limit in range(100, 200):
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sys.setrecursionlimit(limit)
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threads = []
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for _ in range(5):
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threads.append(Thread(target=set_recursion_limit))
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for _ in range(5):
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threads.append(Thread(target=something_recursive))
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with threading_helper.catch_threading_exception() as cm:
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with threading_helper.start_threads(threads):
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pass
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if cm.exc_value:
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raise cm.exc_value
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def test_getwindowsversion(self):
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# Raise SkipTest if sys doesn't have getwindowsversion attribute
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test.support.get_attribute(sys, "getwindowsversion")

‎Misc/NEWS.d/next/Core_and_Builtins/2025-01-11-12-39-17.gh-issue-128717.i65d06.rst

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Fix a crash when setting the recursion limit while other threads are active
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on the :term:`free threaded <free threading>` build.

‎Python/ceval.c

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@@ -265,12 +265,16 @@ void
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Py_SetRecursionLimit(int new_limit)
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{
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PyInterpreterState *interp = _PyInterpreterState_GET();
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_PyEval_StopTheWorld(interp);
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HEAD_LOCK(interp->runtime);
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interp->ceval.recursion_limit = new_limit;
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for (PyThreadState *p = interp->threads.head; p != NULL; p = p->next) {
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int depth = p->py_recursion_limit - p->py_recursion_remaining;
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p->py_recursion_limit = new_limit;
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p->py_recursion_remaining = new_limit - depth;
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}
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HEAD_UNLOCK(interp->runtime);
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_PyEval_StartTheWorld(interp);
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}
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/* The function _Py_EnterRecursiveCallTstate() only calls _Py_CheckRecursiveCall()

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