Closed
Description
Bug report
Bug description:
In the following code it appears we race on the dk_nentries of a split keys dict.
import concurrent.futures
import functools
import threading
import _testcapi
num_threads = 32
def closure(b, i):
b.wait()
h = _testcapi.HeapCTypeWithManagedDict()
h.__dict__[f"asdf{i}"] = "bar"
with concurrent.futures.ThreadPoolExecutor(max_workers=num_threads) as executor:
for i in range(1000):
b = threading.Barrier(num_threads)
for i in range(num_threads):
executor.submit(functools.partial(closure, b, i))TSAN report:
WARNING: ThreadSanitizer: data race (pid=3466735)
Read of size 8 at 0x7ffa06cba218 by thread T32:
#0 dict_dealloc /usr/local/google/home/phawkins/p/cpython/Objects/dictobject.c:3170:42 (python3.13+0x26b02f) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#1 _Py_Dealloc /usr/local/google/home/phawkins/p/cpython/Objects/object.c:2935:5 (python3.13+0x2906a2) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#2 _Py_MergeZeroLocalRefcount /usr/local/google/home/phawkins/p/cpython/Objects/object.c (python3.13+0x2906a2)
#3 Py_DECREF /usr/local/google/home/phawkins/p/cpython/./Include/object.h:913:13 (python3.13+0x271cf7) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#4 Py_XDECREF /usr/local/google/home/phawkins/p/cpython/./Include/object.h:1042:9 (python3.13+0x271cf7)
#5 _PyObject_SetManagedDict /usr/local/google/home/phawkins/p/cpython/Objects/dictobject.c:7151:13 (python3.13+0x271cf7)
#6 PyObject_ClearManagedDict /usr/local/google/home/phawkins/p/cpython/Objects/dictobject.c:7175:9 (python3.13+0x272317) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#7 heapmanaged_dealloc /usr/local/google/home/phawkins/p/cpython/./Modules/_testcapi/heaptype.c:822:5 (_testcapi.cpython-313t-x86_64-linux-gnu.so+0x21566) (BuildId: bcb92e2e6763ccff2c40c066ebaf418e7c3dee07)
#8 _Py_Dealloc /usr/local/google/home/phawkins/p/cpython/Objects/object.c:2935:5 (python3.13+0x2906a2) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#9 _Py_MergeZeroLocalRefcount /usr/local/google/home/phawkins/p/cpython/Objects/object.c (python3.13+0x2906a2)
#10 Py_DECREF /usr/local/google/home/phawkins/p/cpython/./Include/object.h:913:13 (python3.13+0x227b98) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#11 frame_dealloc /usr/local/google/home/phawkins/p/cpython/Objects/frameobject.c:1728:13 (python3.13+0x227b98)
#12 _Py_Dealloc /usr/local/google/home/phawkins/p/cpython/Objects/object.c:2935:5 (python3.13+0x2906a2) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#13 _Py_MergeZeroLocalRefcount /usr/local/google/home/phawkins/p/cpython/Objects/object.c (python3.13+0x2906a2)
#14 Py_DECREF /usr/local/google/home/phawkins/p/cpython/./Include/object.h:913:13 (python3.13+0x4bde23) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#15 Py_XDECREF /usr/local/google/home/phawkins/p/cpython/./Include/object.h:1042:9 (python3.13+0x4bde23)
#16 tb_dealloc /usr/local/google/home/phawkins/p/cpython/Python/traceback.c:188:5 (python3.13+0x4bde23)
#17 _Py_Dealloc /usr/local/google/home/phawkins/p/cpython/Objects/object.c:2935:5 (python3.13+0x2906a2) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#18 _Py_MergeZeroLocalRefcount /usr/local/google/home/phawkins/p/cpython/Objects/object.c (python3.13+0x2906a2)
#19 Py_DECREF /usr/local/google/home/phawkins/p/cpython/./Include/object.h:913:13 (python3.13+0x4bdda3) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#20 Py_XDECREF /usr/local/google/home/phawkins/p/cpython/./Include/object.h:1042:9 (python3.13+0x4bdda3)
#21 tb_dealloc /usr/local/google/home/phawkins/p/cpython/Python/traceback.c:187:5 (python3.13+0x4bdda3)
#22 _Py_Dealloc /usr/local/google/home/phawkins/p/cpython/Objects/object.c:2935:5 (python3.13+0x2906a2) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#23 _Py_MergeZeroLocalRefcount /usr/local/google/home/phawkins/p/cpython/Objects/object.c (python3.13+0x2906a2)
#24 Py_DECREF /usr/local/google/home/phawkins/p/cpython/./Include/object.h:913:13 (python3.13+0x209a86) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#25 BaseException_clear /usr/local/google/home/phawkins/p/cpython/Objects/exceptions.c:87:5 (python3.13+0x209a86)
#26 NameError_clear /usr/local/google/home/phawkins/p/cpython/Objects/exceptions.c:2228:12 (python3.13+0x210fac) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#27 NameError_dealloc /usr/local/google/home/phawkins/p/cpython/Objects/exceptions.c:2235:5 (python3.13+0x210fac)
#28 _Py_Dealloc /usr/local/google/home/phawkins/p/cpython/Objects/object.c:2935:5 (python3.13+0x2904a5) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#29 merge_queued_objects /usr/local/google/home/phawkins/p/cpython/Python/brc.c:110:13 (python3.13+0x3dca2a) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#30 _Py_brc_merge_refcounts /usr/local/google/home/phawkins/p/cpython/Python/brc.c:131:5 (python3.13+0x3dca2a)
#31 _Py_HandlePending /usr/local/google/home/phawkins/p/cpython/Python/ceval_gil.c:1289:9 (python3.13+0x45358e) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#32 _PyEval_EvalFrameDefault /usr/local/google/home/phawkins/p/cpython/Python/generated_cases.c.h:5160:17 (python3.13+0x3f2f00) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#33 _PyEval_EvalFrame /usr/local/google/home/phawkins/p/cpython/./Include/internal/pycore_ceval.h:119:16 (python3.13+0x3de77a) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#34 _PyEval_Vector /usr/local/google/home/phawkins/p/cpython/Python/ceval.c:1812:12 (python3.13+0x3de77a)
#35 _PyFunction_Vectorcall /usr/local/google/home/phawkins/p/cpython/Objects/call.c (python3.13+0x1eb3bf) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#36 _PyObject_VectorcallTstate /usr/local/google/home/phawkins/p/cpython/./Include/internal/pycore_call.h:168:11 (python3.13+0x1ef2d5) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#37 method_vectorcall /usr/local/google/home/phawkins/p/cpython/Objects/classobject.c:62:18 (python3.13+0x1ef2d5)
#38 _PyObject_VectorcallTstate /usr/local/google/home/phawkins/p/cpython/./Include/internal/pycore_call.h:168:11 (python3.13+0x1ead4a) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#39 PyObject_Vectorcall /usr/local/google/home/phawkins/p/cpython/Objects/call.c:327:12 (python3.13+0x1ead4a)
#40 _PyEval_EvalFrameDefault /usr/local/google/home/phawkins/p/cpython/Python/generated_cases.c.h:813:23 (python3.13+0x3e264b) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#41 _PyEval_EvalFrame /usr/local/google/home/phawkins/p/cpython/./Include/internal/pycore_ceval.h:119:16 (python3.13+0x3de77a) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#42 _PyEval_Vector /usr/local/google/home/phawkins/p/cpython/Python/ceval.c:1812:12 (python3.13+0x3de77a)
#43 _PyFunction_Vectorcall /usr/local/google/home/phawkins/p/cpython/Objects/call.c (python3.13+0x1eb3bf) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#44 _PyObject_VectorcallTstate /usr/local/google/home/phawkins/p/cpython/./Include/internal/pycore_call.h:168:11 (python3.13+0x1ef38f) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#45 method_vectorcall /usr/local/google/home/phawkins/p/cpython/Objects/classobject.c:70:20 (python3.13+0x1ef38f)
#46 _PyVectorcall_Call /usr/local/google/home/phawkins/p/cpython/Objects/call.c:273:16 (python3.13+0x1eb033) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#47 _PyObject_Call /usr/local/google/home/phawkins/p/cpython/Objects/call.c:348:16 (python3.13+0x1eb033)
#48 PyObject_Call /usr/local/google/home/phawkins/p/cpython/Objects/call.c:373:12 (python3.13+0x1eb0b5) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#49 thread_run /usr/local/google/home/phawkins/p/cpython/./Modules/_threadmodule.c:337:21 (python3.13+0x5649a2) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#50 pythread_wrapper /usr/local/google/home/phawkins/p/cpython/Python/thread_pthread.h:243:5 (python3.13+0x4bdca7) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
Previous atomic write of size 8 at 0x7ffa06cba218 by thread T2:
#0 _Py_atomic_store_ssize_relaxed /usr/local/google/home/phawkins/p/cpython/./Include/cpython/pyatomic_gcc.h:481:3 (python3.13+0x273284) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#1 split_keys_entry_added /usr/local/google/home/phawkins/p/cpython/Objects/dictobject.c:225:5 (python3.13+0x273284)
#2 insert_split_key /usr/local/google/home/phawkins/p/cpython/Objects/dictobject.c:1743:9 (python3.13+0x273284)
#3 insertdict /usr/local/google/home/phawkins/p/cpython/Objects/dictobject.c:1796:25 (python3.13+0x263496) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#4 setitem_take2_lock_held /usr/local/google/home/phawkins/p/cpython/Objects/dictobject.c:2507:12 (python3.13+0x262996) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#5 _PyDict_SetItem_Take2 /usr/local/google/home/phawkins/p/cpython/Objects/dictobject.c:2515:11 (python3.13+0x262bcf) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#6 PyDict_SetItem /usr/local/google/home/phawkins/p/cpython/Objects/dictobject.c:2535:12 (python3.13+0x262bcf)
#7 dict_ass_sub /usr/local/google/home/phawkins/p/cpython/Objects/dictobject.c:3340:16 (python3.13+0x27557a) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#8 PyObject_SetItem /usr/local/google/home/phawkins/p/cpython/Objects/abstract.c:232:19 (python3.13+0x1b9488) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#9 _PyEval_EvalFrameDefault /usr/local/google/home/phawkins/p/cpython/Python/generated_cases.c.h:5777:27 (python3.13+0x3f5d0b) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#10 _PyEval_EvalFrame /usr/local/google/home/phawkins/p/cpython/./Include/internal/pycore_ceval.h:119:16 (python3.13+0x3de77a) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#11 _PyEval_Vector /usr/local/google/home/phawkins/p/cpython/Python/ceval.c:1812:12 (python3.13+0x3de77a)
#12 _PyFunction_Vectorcall /usr/local/google/home/phawkins/p/cpython/Objects/call.c (python3.13+0x1eb3bf) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#13 _PyObject_VectorcallTstate /usr/local/google/home/phawkins/p/cpython/./Include/internal/pycore_call.h:168:11 (python3.13+0x5722c2) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#14 partial_vectorcall /usr/local/google/home/phawkins/p/cpython/./Modules/_functoolsmodule.c:252:16 (python3.13+0x5722c2)
#15 _PyVectorcall_Call /usr/local/google/home/phawkins/p/cpython/Objects/call.c:273:16 (python3.13+0x1eb033) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#16 _PyObject_Call /usr/local/google/home/phawkins/p/cpython/Objects/call.c:348:16 (python3.13+0x1eb033)
#17 PyObject_Call /usr/local/google/home/phawkins/p/cpython/Objects/call.c:373:12 (python3.13+0x1eb0b5) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#18 _PyEval_EvalFrameDefault /usr/local/google/home/phawkins/p/cpython/Python/generated_cases.c.h:1355:26 (python3.13+0x3e4832) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#19 _PyEval_EvalFrame /usr/local/google/home/phawkins/p/cpython/./Include/internal/pycore_ceval.h:119:16 (python3.13+0x3de77a) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#20 _PyEval_Vector /usr/local/google/home/phawkins/p/cpython/Python/ceval.c:1812:12 (python3.13+0x3de77a)
#21 _PyFunction_Vectorcall /usr/local/google/home/phawkins/p/cpython/Objects/call.c (python3.13+0x1eb3bf) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#22 _PyObject_VectorcallTstate /usr/local/google/home/phawkins/p/cpython/./Include/internal/pycore_call.h:168:11 (python3.13+0x1ef38f) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#23 method_vectorcall /usr/local/google/home/phawkins/p/cpython/Objects/classobject.c:70:20 (python3.13+0x1ef38f)
#24 _PyVectorcall_Call /usr/local/google/home/phawkins/p/cpython/Objects/call.c:273:16 (python3.13+0x1eb033) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#25 _PyObject_Call /usr/local/google/home/phawkins/p/cpython/Objects/call.c:348:16 (python3.13+0x1eb033)
#26 PyObject_Call /usr/local/google/home/phawkins/p/cpython/Objects/call.c:373:12 (python3.13+0x1eb0b5) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#27 thread_run /usr/local/google/home/phawkins/p/cpython/./Modules/_threadmodule.c:337:21 (python3.13+0x5649a2) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
#28 pythread_wrapper /usr/local/google/home/phawkins/p/cpython/Python/thread_pthread.h:243:5 (python3.13+0x4bdca7) (BuildId: eba64ecb5d6238e288495b7377dad10e1b152da3)
CPython versions tested on:
3.13
Operating systems tested on:
Linux