gh-116738: Move run_concurrently() to threading_helper

Author: yoney

Lib/test/support/threading_helper.py

@@ -248,3 +248,27 @@ def requires_working_threading(*, module=False):
             raise unittest.SkipTest(msg)
     else:
         return unittest.skipUnless(can_start_thread, msg)
+
+
+def run_concurrently(worker_func, args, nthreads):
+    """
+    Run the worker function concurrently in multiple threads.
+    """
+    barrier = threading.Barrier(nthreads)
+
+    def wrapper_func(*args):
+        # Wait for all threads to reach this point before proceeding.
+        barrier.wait()
+        worker_func(*args)
+
+    with catch_threading_exception() as cm:
+        workers = (
+            threading.Thread(target=wrapper_func, args=args)
+            for _ in range(nthreads)
+        )
+        with start_threads(workers):
+            pass
+
+        # If a worker thread raises an exception, re-raise it.
+        if cm.exc_value is not None:
+            raise cm.exc_value

Lib/test/test_free_threading/test_ft.py

@@ -1,7 +1,7 @@
 import unittest
 
 from test.support import import_helper, threading_helper
-from test.test_free_threading.test_ft import run_concurrently
+from test.support.threading_helper import run_concurrently
 
 grp = import_helper.import_module("grp")
 

Lib/test/test_free_threading/test_grp.py

@@ -7,7 +7,7 @@
 from random import shuffle, randint
 
 from test.support import threading_helper
-from test.test_free_threading.test_ft import run_concurrently
+from test.support.threading_helper import run_concurrently
 from test import test_heapq