From 097ee8f2879d9cdedfec0f56c9a6873cbc7be203 Mon Sep 17 00:00:00 2001
From: Yizhi Liu <liuyizhi@apache.org>
Date: Tue, 22 Oct 2019 23:39:11 -0700
Subject: [PATCH] add doc for CallbackChannel

---
 src/runtime/rpc/rpc_event_impl.cc |  6 +++++-
 src/runtime/rpc/rpc_session.h     | 12 ++++--------
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/src/runtime/rpc/rpc_event_impl.cc b/src/runtime/rpc/rpc_event_impl.cc
index 3a7606f2b6b6..3f4782693d8a 100644
--- a/src/runtime/rpc/rpc_event_impl.cc
+++ b/src/runtime/rpc/rpc_event_impl.cc
@@ -32,7 +32,11 @@ namespace runtime {
 PackedFunc CreateEventDrivenServer(PackedFunc fsend,
                                    std::string name,
                                    std::string remote_key) {
-  std::unique_ptr<CallbackChannel> ch(new CallbackChannel(fsend));
+  static PackedFunc frecv([](TVMArgs args, TVMRetValue* rv) {
+    LOG(FATAL) << "Do not allow explicit receive";
+    return 0;
+  });
+  std::unique_ptr<CallbackChannel> ch(new CallbackChannel(fsend, frecv));
   std::shared_ptr<RPCSession> sess =
       RPCSession::Create(std::move(ch), name, remote_key);
   return PackedFunc([sess](TVMArgs args, TVMRetValue* rv) {
diff --git a/src/runtime/rpc/rpc_session.h b/src/runtime/rpc/rpc_session.h
index 257f395f51d2..d982f68bcb6e 100644
--- a/src/runtime/rpc/rpc_session.h
+++ b/src/runtime/rpc/rpc_session.h
@@ -253,19 +253,15 @@ class RPCSession {
   std::string remote_key_;
 };
 
+/*!
+ * \brief RPC channel which callback
+ * frontend (Python/Java/etc.)'s send & recv function
+ */
 class CallbackChannel final : public RPCChannel {
  public:
   explicit CallbackChannel(PackedFunc fsend, PackedFunc frecv)
       : fsend_(std::move(fsend)), frecv_(std::move(frecv)) {}
 
-  explicit CallbackChannel(PackedFunc fsend)
-      : fsend_(std::move(fsend)) {
-    PackedFunc frecv([](TVMArgs args, TVMRetValue* rv) {
-      LOG(FATAL) << "Do not allow explicit receive";
-      return 0;
-    });
-    frecv_ = frecv;
-  }
   ~CallbackChannel() {}
   /*!
    * \brief Send data over to the channel.