Extend tests a little, add suppressions with links to GH issues.

Author: Yhg1s

Lib/test/test_free_threading/test_iteration.py

@@ -1,4 +1,3 @@
-import sys
 import threading
 import unittest
 from test import support
@@ -14,7 +13,7 @@
     NUMTHREADS = 2
 else:
     NUMITEMS = 100000
-    NUMTHREADS = 3
+    NUMTHREADS = 5
 NUMMUTATORS = 2
 
 class ContendedTupleIterationTest(unittest.TestCase):
@@ -88,7 +87,10 @@ def mutator():
             replacement = (orig * 3)[NUMITEMS//2:]
             start.wait()
             while not endmutate.is_set():
-                seq[:] = replacement
+                seq.extend(replacement)
+                seq[:0] = orig
+                seq.__imul__(2)
+                seq.extend(seq)
                 seq[:] = orig
         def worker():
             items = []
@@ -124,7 +126,7 @@ def assert_iterator_results(self, results, expected):
         for item in extra_items:
             self.assertEqual((item - expected.start) % expected.step, 0)
 
-# Long iterators are not thread-safe yet.
+# Long range iterators are not thread-safe yet.
 # class ContendedLongRangeIterationTest(ContendedTupleIterationTest):
 #     def make_testdata(self, n):
 #         return range(0, sys.maxsize*n, sys.maxsize)

Objects/listobject.c

@@ -784,7 +784,8 @@ list_repeat_lock_held(PyListObject *a, Py_ssize_t n)
             _Py_RefcntAdd(*src, n);
             *dest++ = *src++;
         }
-
+        // TODO: _Py_memory_repeat calls are not safe for shared lists in
+        // GIL_DISABLED builds. (See issue #129069)
         _Py_memory_repeat((char *)np->ob_item, sizeof(PyObject *)*output_size,
                                         sizeof(PyObject *)*input_size);
     }
@@ -920,7 +921,7 @@ list_ass_slice_lock_held(PyListObject *a, Py_ssize_t ilow, Py_ssize_t ihigh, PyO
         Py_ssize_t tail;
         tail = (Py_SIZE(a) - ihigh) * sizeof(PyObject *);
         // TODO: these memmove/memcpy calls are not safe for shared lists in
-        // GIL_DISABLED builds.
+        // GIL_DISABLED builds. (See issue #129069)
         memmove(&item[ihigh+d], &item[ihigh], tail);
         if (list_resize(a, Py_SIZE(a) + d) < 0) {
             memmove(&item[ihigh], &item[ihigh+d], tail);
@@ -935,7 +936,7 @@ list_ass_slice_lock_held(PyListObject *a, Py_ssize_t ilow, Py_ssize_t ihigh, PyO
             goto Error;
         item = a->ob_item;
         // TODO: these memmove/memcpy calls are not safe for shared lists in
-        // GIL_DISABLED builds.
+        // GIL_DISABLED builds. (See issue #129069)
         memmove(&item[ihigh+d], &item[ihigh],
             (k - ihigh)*sizeof(PyObject *));
     }
@@ -1021,6 +1022,8 @@ list_inplace_repeat_lock_held(PyListObject *self, Py_ssize_t n)
     for (Py_ssize_t j = 0; j < input_size; j++) {
         _Py_RefcntAdd(items[j], n-1);
     }
+    // TODO: _Py_memory_repeat calls are not safe for shared lists in
+    // GIL_DISABLED builds. (See issue #129069)
     _Py_memory_repeat((char *)items, sizeof(PyObject *)*output_size,
                       sizeof(PyObject *)*input_size);
     return 0;

Tools/tsan/suppressions_free_threading.txt

@@ -18,13 +18,11 @@ race:set_allocator_unlocked
 # https://gist.github.com/swtaarrs/08dfe7883b4c975c31ecb39388987a67
 race:free_threadstate
 
-
 # These warnings trigger directly in a CPython function.
 
 race_top:assign_version_tag
 race_top:new_reference
 race_top:_multiprocessing_SemLock_acquire_impl
-race_top:list_get_item_ref
 race_top:_Py_slot_tp_getattr_hook
 race_top:add_threadstate
 race_top:dump_traceback
@@ -46,3 +44,12 @@ race_top:set_default_allocator_unlocked
 
 # https://gist.github.com/mpage/6962e8870606cfc960e159b407a0cb40
 thread:pthread_create
+
+# Range iteration is not thread-safe yet (issue #129068)
+race_top:rangeiter_next
+
+# List resizing happens through different paths ending in memcpy or memmove
+# (for efficiency), which will probably need to rewritten as explicit loops
+# of ptr-sized copies to be thread-safe. (Issue #129069)
+race:list_ass_slice_lock_held
+race:list_inplace_repeat_lock_held