Add unittest for C++ RPC (#566)

src/graph/network/socket_communicator.h

@@ -96,7 +96,7 @@ class SocketSender : public Sender {
   /*!
    * \brief data buffer
    */ 
-  char* buffer_;
+  char* buffer_ = nullptr;
 };
 
 /*!
@@ -174,7 +174,7 @@ class SocketReceiver : public Receiver {
   /*!
    * \brief data buffer
    */ 
-  char* buffer_;
+  char* buffer_ = nullptr;
 
   /*!
    * \brief Process received message in independent threads

tests/cpp/socket_communicator_test.cc

+/*!
+ *  Copyright (c) 2019 by Contributors
+ * \file msg_queue.cc
+ * \brief Message queue for DGL distributed training.
+ */
+#include <gtest/gtest.h>
+#include <string.h>
+#include <unistd.h>
+#include <string>
+
+#include "../src/graph/network/socket_communicator.h"
+
+using std::string;
+using dgl::network::SocketSender;
+using dgl::network::SocketReceiver;
+
+TEST(SocketCommunicatorTest, SendAndRecv) {
+  int pid = fork();
+  const char * msg = "0123456789";
+  ASSERT_GE(pid, 0);
+  if (pid > 0) {  // parent: server
+  	char serbuff[10];
+    memset(serbuff, '\0', 10);
+  	SocketReceiver receiver;
+  	receiver.Wait("127.0.0.1", 50051, 1, 500);
+    receiver.Recv(serbuff, 10);
+    ASSERT_EQ(string("0123456789"), string(serbuff, 10));
+    receiver.Finalize();
+  } else {  // child: client
+    sleep(1);
+  	SocketSender sender;
+  	sender.AddReceiver("127.0.0.1", 50051, 0);
+  	sender.Connect();
+  	sender.Send(msg, 10, 0);
+  	sender.Finalize();
+  }
+}
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tests/cpp/tcp_socket_test.cc

@@ -75,7 +75,7 @@ TEST(TCPSocket, SendRecieve) {
       sent_bytes += tmp;
     }
   } else {  // child: client
-    sleep(3);   // wait for server
+    sleep(1);   // wait for server
     TCPSocket client;
     ASSERT_TRUE(client.Connect("127.0.0.1", 2049));
     char clibuff[10];
@@ -124,5 +124,4 @@ TEST(TCPSocket, SendRecieve) {
       ASSERT_EQ(bigbuff[i], 'x');
     }
   }
-  wait(0);
 }
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