Mock recvmmsg in AsyncUDPSocket

Summary: as title, just to add a mock function

Reviewed By: yfeldblum, lnicco

Differential Revision: D20130909

fbshipit-source-id: 469d904cce93dc8e88c5dc4728b1f1fbd0baf798

folly/io/async/test/MockAsyncUDPSocket.h

@@ -55,6 +55,9 @@ struct MockAsyncUDPSocket : public AsyncUDPSocket {
   MOCK_METHOD0(getGSO, int());
   MOCK_METHOD1(setGSO, bool(int));
   MOCK_METHOD2(recvmsg, ssize_t(struct msghdr*, int));
+  MOCK_METHOD4(
+      recvmmsg,
+      int(struct mmsghdr*, unsigned int, unsigned int, struct timespec*));
 };
 
 } // namespace test