From: Kevin Wang <kevmo314@gmail.com>
Date: Wed, 10 Dec 2025 07:29:40 +0000 (-0500)
Subject: gh-142048: Fix lost gc allocations count on thread cleanup (#142233)
X-Git-Tag: v3.15.0a3~129
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=49b1fb43f65290dadeb83ed6f7c0c74995fda7a1;p=thirdparty%2FPython%2Fcpython.git

gh-142048: Fix lost gc allocations count on thread cleanup (#142233)
---

diff --git a/Python/pystate.c b/Python/pystate.c
index 2956e785405a..4bf89a234266 100644
--- a/Python/pystate.c
+++ b/Python/pystate.c
@@ -1765,16 +1765,23 @@ PyThreadState_Clear(PyThreadState *tstate)
     struct _Py_freelists *freelists = _Py_freelists_GET();
     _PyObject_ClearFreeLists(freelists, 1);
 
+    // Flush the thread's local GC allocation count to the global count
+    // before the thread state is cleared, otherwise the count is lost.
+    _PyThreadStateImpl *tstate_impl = (_PyThreadStateImpl *)tstate;
+    _Py_atomic_add_int(&tstate->interp->gc.young.count,
+                       (int)tstate_impl->gc.alloc_count);
+    tstate_impl->gc.alloc_count = 0;
+
     // Merge our thread-local refcounts into the type's own refcount and
     // free our local refcount array.
-    _PyObject_FinalizePerThreadRefcounts((_PyThreadStateImpl *)tstate);
+    _PyObject_FinalizePerThreadRefcounts(tstate_impl);
 
     // Remove ourself from the biased reference counting table of threads.
     _Py_brc_remove_thread(tstate);
 
     // Release our thread-local copies of the bytecode for reuse by another
     // thread
-    _Py_ClearTLBCIndex((_PyThreadStateImpl *)tstate);
+    _Py_ClearTLBCIndex(tstate_impl);
 #endif
 
     // Merge our queue of pointers to be freed into the interpreter queue.