bpo-19696: Move threaded_import_hangers (GH-14655)

Move `threaded_import_hangers`, a dependency of `test_threaded_import`, to the directory `test_importlib/`. Also update the import references for `threaded_import_hangers` in `test_threaded_import`.





https://bugs.python.org/issue19696

2 files changed, 48 insertions, 3 deletions

diff --git a/Lib/test/test_importlib/test_threaded_import.py b/Lib/test/test_importlib/test_threaded_import.py
index 8607f36..d1f64c7 100644
--- a/Lib/test/test_importlib/test_threaded_import.py
+++ b/Lib/test/test_importlib/test_threaded_import.py
@@ -178,11 +178,11 @@ class ThreadedImportTests(unittest.TestCase):
         # In case this test is run again, make sure the helper module
         # gets loaded from scratch again.
         try:
-            del sys.modules['test.threaded_import_hangers']
+            del sys.modules['test.test_importlib.threaded_import_hangers']
         except KeyError:
             pass
-        import test.threaded_import_hangers
-        self.assertFalse(test.threaded_import_hangers.errors)
+        import test.test_importlib.threaded_import_hangers
+        self.assertFalse(test.test_importlib.threaded_import_hangers.errors)
 
     def test_circular_imports(self):
         # The goal of this test is to exercise implementations of the import
diff --git a/Lib/test/test_importlib/threaded_import_hangers.py b/Lib/test/test_importlib/threaded_import_hangers.py
new file mode 100644
index 0000000..5484e60
--- /dev/null
+++ b/Lib/test/test_importlib/threaded_import_hangers.py
@@ -0,0 +1,45 @@
+# This is a helper module for test_threaded_import.  The test imports this
+# module, and this module tries to run various Python library functions in
+# their own thread, as a side effect of being imported.  If the spawned
+# thread doesn't complete in TIMEOUT seconds, an "appeared to hang" message
+# is appended to the module-global `errors` list.  That list remains empty
+# if (and only if) all functions tested complete.
+
+TIMEOUT = 10
+
+import threading
+
+import tempfile
+import os.path
+
+errors = []
+
+# This class merely runs a function in its own thread T.  The thread importing
+# this module holds the import lock, so if the function called by T tries
+# to do its own imports it will block waiting for this module's import
+# to complete.
+class Worker(threading.Thread):
+    def __init__(self, function, args):
+        threading.Thread.__init__(self)
+        self.function = function
+        self.args = args
+
+    def run(self):
+        self.function(*self.args)
+
+for name, func, args in [
+        # Bug 147376:  TemporaryFile hung on Windows, starting in Python 2.4.
+        ("tempfile.TemporaryFile", lambda: tempfile.TemporaryFile().close(), ()),
+
+        # The real cause for bug 147376:  ntpath.abspath() caused the hang.
+        ("os.path.abspath", os.path.abspath, ('.',)),
+        ]:
+
+    try:
+        t = Worker(func, args)
+        t.start()
+        t.join(TIMEOUT)
+        if t.is_alive():
+            errors.append("%s appeared to hang" % name)
+    finally:
+        del t