test_threading: use Popen.communicate() instead of .wait()
Popen.communicate() avoids deadlocks and close the pipes when done. This commit
fixes a ResourceWarning(unclosed pipe).
diff --git a/Lib/test/test_threading.py b/Lib/test/test_threading.py
index f3d5a4c..46d2f47 100644
--- a/Lib/test/test_threading.py
+++ b/Lib/test/test_threading.py
@@ -512,9 +512,9 @@
def assertScriptHasOutput(self, script, expected_output):
p = subprocess.Popen([sys.executable, "-c", script],
stdout=subprocess.PIPE)
- rc = p.wait()
- data = p.stdout.read().decode().replace('\r', '')
- self.assertEqual(rc, 0, "Unexpected error")
+ stdout, stderr = p.communicate()
+ data = stdout.decode().replace('\r', '')
+ self.assertEqual(p.returncode, 0, "Unexpected error")
self.assertEqual(data, expected_output)
@unittest.skipUnless(hasattr(os, 'fork'), "needs os.fork()")