bpo-43517: Fix false positive in detection of circular imports (#24895)
diff --git a/Lib/test/test_importlib/partial/cfimport.py b/Lib/test/test_importlib/partial/cfimport.py
new file mode 100644
index 0000000..c92d2fe
--- /dev/null
+++ b/Lib/test/test_importlib/partial/cfimport.py
@@ -0,0 +1,38 @@
+import os
+import sys
+import threading
+import traceback
+
+
+NLOOPS = 50
+NTHREADS = 30
+
+
+def t1():
+ try:
+ from concurrent.futures import ThreadPoolExecutor
+ except Exception:
+ traceback.print_exc()
+ os._exit(1)
+
+def t2():
+ try:
+ from concurrent.futures.thread import ThreadPoolExecutor
+ except Exception:
+ traceback.print_exc()
+ os._exit(1)
+
+def main():
+ for j in range(NLOOPS):
+ threads = []
+ for i in range(NTHREADS):
+ threads.append(threading.Thread(target=t2 if i % 1 else t1))
+ for thread in threads:
+ thread.start()
+ for thread in threads:
+ thread.join()
+ sys.modules.pop('concurrent.futures', None)
+ sys.modules.pop('concurrent.futures.thread', None)
+
+if __name__ == "__main__":
+ main()
diff --git a/Lib/test/test_importlib/partial/pool_in_threads.py b/Lib/test/test_importlib/partial/pool_in_threads.py
new file mode 100644
index 0000000..faa7867
--- /dev/null
+++ b/Lib/test/test_importlib/partial/pool_in_threads.py
@@ -0,0 +1,27 @@
+import multiprocessing
+import os
+import threading
+import traceback
+
+
+def t():
+ try:
+ with multiprocessing.Pool(1):
+ pass
+ except Exception:
+ traceback.print_exc()
+ os._exit(1)
+
+
+def main():
+ threads = []
+ for i in range(20):
+ threads.append(threading.Thread(target=t))
+ for thread in threads:
+ thread.start()
+ for thread in threads:
+ thread.join()
+
+
+if __name__ == "__main__":
+ main()
diff --git a/Lib/test/test_importlib/test_threaded_import.py b/Lib/test/test_importlib/test_threaded_import.py
index c6a6e17..03bde96 100644
--- a/Lib/test/test_importlib/test_threaded_import.py
+++ b/Lib/test/test_importlib/test_threaded_import.py
@@ -17,7 +17,7 @@
from test.support import (verbose, run_unittest)
from test.support.import_helper import forget
from test.support.os_helper import (TESTFN, unlink, rmtree)
-from test.support import threading_helper
+from test.support import script_helper, threading_helper
def task(N, done, done_tasks, errors):
try:
@@ -245,6 +245,18 @@ def target():
__import__(TESTFN)
del sys.modules[TESTFN]
+ def test_concurrent_futures_circular_import(self):
+ # Regression test for bpo-43515
+ fn = os.path.join(os.path.dirname(__file__),
+ 'partial', 'cfimport.py')
+ script_helper.assert_python_ok(fn)
+
+ def test_multiprocessing_pool_circular_import(self):
+ # Regression test for bpo-41567
+ fn = os.path.join(os.path.dirname(__file__),
+ 'partial', 'pool_in_threads.py')
+ script_helper.assert_python_ok(fn)
+
@threading_helper.reap_threads
def test_main():
diff --git a/Misc/NEWS.d/next/Core and Builtins/2021-03-16-17-12-54.bpo-43517.zAo6Ws.rst b/Misc/NEWS.d/next/Core and Builtins/2021-03-16-17-12-54.bpo-43517.zAo6Ws.rst
new file mode 100644
index 0000000..0f9926b
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2021-03-16-17-12-54.bpo-43517.zAo6Ws.rst
@@ -0,0 +1,2 @@
+Fix misdetection of circular imports when using ``from pkg.mod import
+attr``, which caused false positives in non-trivial multi-threaded code.
diff --git a/Python/import.c b/Python/import.c
index 538db69..d92e46a 100644
--- a/Python/import.c
+++ b/Python/import.c
@@ -1593,7 +1593,7 @@ PyImport_ImportModuleLevelObject(PyObject *name, PyObject *globals,
}
if (mod != NULL && mod != Py_None) {
- if (import_ensure_initialized(tstate->interp, mod, name) < 0) {
+ if (import_ensure_initialized(tstate->interp, mod, abs_name) < 0) {
goto error;
}
}