Workaround socket library import issue. (#601)
diff --git a/mobly/controllers/android_device_lib/jsonrpc_client_base.py b/mobly/controllers/android_device_lib/jsonrpc_client_base.py
index abe0bbb..1d6f7aa 100644
--- a/mobly/controllers/android_device_lib/jsonrpc_client_base.py
+++ b/mobly/controllers/android_device_lib/jsonrpc_client_base.py
@@ -41,6 +41,18 @@
from builtins import str
+# When the Python library `socket.create_connection` call is made, it indirectly
+# calls `import encodings.idna` through the `socket.getaddrinfo` method.
+# However, this chain of function calls is apparently not thread-safe in
+# embedded Python environments. So, pre-emptively import and cache the encoder.
+# See https://bugs.python.org/issue17305 for more details.
+try:
+ import encodings.idna
+except ImportError:
+ # Some implementations of Python (e.g. IronPython) do not support the`idna`
+ # encoding, so ignore import failures based on that.
+ pass
+
import json
import socket
import threading
