Add rpc_client interface. (#11154)

paddle/fluid/operators/detail/CMakeLists.txt

 if(WITH_DISTRIBUTE)
   grpc_library(sendrecvop_grpc SRCS bytebuffer_stream.cc sendrecvop_utils.cc grpc_client.cc
-      request_handler_impl.cc rpc_server.cc grpc_server.cc variable_response.cc PROTO send_recv.proto DEPS lod_tensor
+      request_handler_impl.cc rpc_client.cc rpc_server.cc grpc_server.cc variable_response.cc PROTO send_recv.proto DEPS lod_tensor
       selected_rows memory)
   set(DISTRIBUTE_COMPILE_FLAGS "-Wno-non-virtual-dtor -Wno-error=non-virtual-dtor -Wno-error=delete-non-virtual-dtor")
   set_source_files_properties(serde_test.cc grpc_server_test.cc PROPERTIES COMPILE_FLAGS ${DISTRIBUTE_COMPILE_FLAGS})

paddle/fluid/operators/detail/grpc_client.cc

@@ -25,29 +25,15 @@ namespace paddle {
 namespace operators {
 namespace detail {
 
-std::once_flag RPCClient::init_flag_;
+void GRPCClient::InitImpl() { InitEventLoop(); }
 
-std::unique_ptr<RPCClient> RPCClient::rpc_client_(nullptr);
-
-RPCClient* RPCClient::GetInstance() {
-  std::call_once(init_flag_, &RPCClient::Init);
-  return rpc_client_.get();
-}
-
-void RPCClient::Init() {
-  if (rpc_client_.get() == nullptr) {
-    rpc_client_.reset(new RPCClient());
-  }
-  rpc_client_->InitEventLoop();
-}
-
-void RPCClient::InitEventLoop() {
+void GRPCClient::InitEventLoop() {
   // start the client process thread
   // TODO(wuyi): can make this in a threadpool
-  client_thread_.reset(new std::thread(std::bind(&RPCClient::Proceed, this)));
+  client_thread_.reset(new std::thread(std::bind(&GRPCClient::Proceed, this)));
 }
 
-RPCClient::~RPCClient() {
+GRPCClient::~GRPCClient() {
   Wait();
   cq_.Shutdown();
   {
@@ -59,11 +45,10 @@ RPCClient::~RPCClient() {
   client_thread_->join();
 }
 
-bool RPCClient::AsyncSendVariable(const std::string& ep,
+bool GRPCClient::AsyncSendVar(const std::string& ep,
                               const platform::DeviceContext& ctx,
                               const framework::Scope& scope,
-                                  const std::string& var_name,
-                                  int64_t time_out) {
+                              const std::string& var_name, int64_t time_out) {
   const platform::DeviceContext* p_ctx = &ctx;
   const std::string ep_val = ep;
   const std::string var_name_val = var_name;
@@ -113,11 +98,10 @@ void RequestToByteBuffer(const T& proto, ::grpc::ByteBuffer* result) {
   result->Swap(&tmp);
 }
 
-bool RPCClient::AsyncGetVariable(const std::string& ep,
+bool GRPCClient::AsyncGetVar(const std::string& ep,
                              const platform::DeviceContext& ctx,
                              const framework::Scope& scope,
-                                 const std::string& var_name,
-                                 int64_t time_out) {
+                             const std::string& var_name, int64_t time_out) {
   const platform::DeviceContext* p_ctx = &ctx;
   const std::string ep_val = ep;
   const std::string var_name_val = var_name;
@@ -155,7 +139,7 @@ bool RPCClient::AsyncGetVariable(const std::string& ep,
   return true;
 }
 
-bool RPCClient::AsyncPrefetchVariable(const std::string& ep,
+bool GRPCClient::AsyncPrefetchVar(const std::string& ep,
                                   const platform::DeviceContext& ctx,
                                   const framework::Scope& scope,
                                   const std::string& in_var_name,
@@ -198,7 +182,8 @@ bool RPCClient::AsyncPrefetchVariable(const std::string& ep,
   return true;
 }
 
-void RPCClient::AsyncSendBatchBarrier(const std::string& ep, int64_t time_out) {
+void GRPCClient::AsyncSendBatchBarrier(const std::string& ep,
+                                       int64_t time_out) {
   const auto ch = GetChannel(ep);
 
   BatchBarrierProcessor* s = new BatchBarrierProcessor(ch);
@@ -211,7 +196,8 @@ void RPCClient::AsyncSendBatchBarrier(const std::string& ep, int64_t time_out) {
   req_count_++;
 }
 
-void RPCClient::AsyncSendFetchBarrier(const std::string& ep, int64_t time_out) {
+void GRPCClient::AsyncSendFetchBarrier(const std::string& ep,
+                                       int64_t time_out) {
   const auto ch = GetChannel(ep);
   FetchBarrierProcessor* s = new FetchBarrierProcessor(ch);
   s->Prepare(time_out);
@@ -223,12 +209,12 @@ void RPCClient::AsyncSendFetchBarrier(const std::string& ep, int64_t time_out) {
   req_count_++;
 }
 
-void RPCClient::Wait() {
+void GRPCClient::Wait() {
   std::unique_lock<std::mutex> lk(sync_mutex_);
   sync_cond_.wait(lk, [this] { return req_count_ == 0; });
 }
 
-void RPCClient::Proceed() {
+void GRPCClient::Proceed() {
   void* tag = nullptr;
   bool ok = false;
 
@@ -251,7 +237,7 @@ void RPCClient::Proceed() {
   }
 }
 
-std::shared_ptr<grpc::Channel> RPCClient::GetChannel(const std::string& ep) {
+std::shared_ptr<grpc::Channel> GRPCClient::GetChannel(const std::string& ep) {
   // TODO(Yancey1989): make grpc client completely thread-safe
   std::lock_guard<std::mutex> guard(chan_mutex_);
   auto it = channels_.find(ep);

paddle/fluid/operators/detail/grpc_client.h

@@ -38,6 +38,7 @@ limitations under the License. */
 #include "paddle/fluid/framework/lod_tensor.h"
 #include "paddle/fluid/framework/scope.h"
 #include "paddle/fluid/framework/selected_rows.h"
+#include "paddle/fluid/operators/detail/rpc_client.h"
 #include "paddle/fluid/operators/detail/sendrecvop_utils.h"
 #include "paddle/fluid/platform/macros.h"  // for DISABLE_COPY_AND_ASSIGN
 
@@ -164,47 +165,46 @@ class FetchBarrierProcessor : public BaseProcessor {
   std::unique_ptr<sendrecv::SendRecvService::Stub> stub_;
 };
 
-class RPCClient {
+class GRPCClient : public RPCClient {
  public:
-  RPCClient() {}
-  ~RPCClient();
+  GRPCClient() {}
+  virtual ~GRPCClient();
 
-  static RPCClient* GetInstance();
+  bool AsyncSendVar(const std::string& ep, const platform::DeviceContext& ctx,
+                    const framework::Scope& scope, const std::string& var_name,
+                    int64_t time_out = RPCClient::rpc_time_out) override;
 
-  bool AsyncSendVariable(const std::string& ep,
-                         const platform::DeviceContext& ctx,
-                         const framework::Scope& scope,
-                         const std::string& var_name,
-                         int64_t time_out = 600 * 1000);
-
-  bool AsyncGetVariable(const std::string& ep,
-                        const platform::DeviceContext& ctx,
-                        const framework::Scope& scope,
-                        const std::string& var_name,
-                        int64_t time_out = 600 * 1000);
+  bool AsyncGetVar(const std::string& ep, const platform::DeviceContext& ctx,
+                   const framework::Scope& scope, const std::string& var_name,
+                   int64_t time_out = RPCClient::rpc_time_out) override;
 
-  bool AsyncPrefetchVariable(const std::string& ep,
+  bool AsyncPrefetchVar(const std::string& ep,
                         const platform::DeviceContext& ctx,
                         const framework::Scope& scope,
                         const std::string& in_var_name,
                         const std::string& out_var_name,
-                             int64_t time_out = 600 * 1000);
+                        int64_t time_out = RPCClient::rpc_time_out) override;
 
-  void AsyncSendBatchBarrier(const std::string& ep,
-                             int64_t time_out = 600 * 1000);
+  void AsyncSendBatchBarrier(
+      const std::string& ep,
+      int64_t time_out = RPCClient::rpc_time_out) override;
 
-  void AsyncSendFetchBarrier(const std::string& ep,
-                             int64_t time_out = 600 * 1000);
+  void AsyncSendFetchBarrier(
+      const std::string& ep,
+      int64_t time_out = RPCClient::rpc_time_out) override;
 
-  void Wait();
+  void Wait() override;
+
+ protected:
+  void InitImpl() override;
+
+ private:
   // InitEventLoop should only be called by Init()
   void InitEventLoop();
 
- private:
   void Proceed();
+
   std::shared_ptr<grpc::Channel> GetChannel(const std::string& ep);
-  // Init is called by GetInstance.
-  static void Init();
 
  private:
   grpc::CompletionQueue cq_;
@@ -218,9 +218,7 @@ class RPCClient {
 
   // mutex for GetChannel thread safety
   std::mutex chan_mutex_;
-  static std::unique_ptr<RPCClient> rpc_client_;
-  static std::once_flag init_flag_;
-  DISABLE_COPY_AND_ASSIGN(RPCClient);
+  DISABLE_COPY_AND_ASSIGN(GRPCClient);
 };
 
 }  // namespace detail

paddle/fluid/operators/detail/grpc_server_test.cc

@@ -19,6 +19,7 @@ limitations under the License. */
 #include "gtest/gtest.h"
 #include "paddle/fluid/operators/detail/grpc_client.h"
 #include "paddle/fluid/operators/detail/grpc_server.h"
+#include "paddle/fluid/operators/detail/rpc_client.h"
 
 #include "paddle/fluid/framework/block_desc.h"
 #include "paddle/fluid/framework/op_registry.h"
@@ -123,7 +124,8 @@ TEST(PREFETCH, CPU) {
   std::thread server_thread(StartServer);
   g_rpc_service->WaitServerReady();
 
-  detail::RPCClient* client = detail::RPCClient::GetInstance();
+  detail::RPCClient* client =
+      detail::RPCClient::GetInstance<detail::GRPCClient>();
   int port = g_rpc_service->GetSelectedPort();
   std::string ep = paddle::string::Sprintf("127.0.0.1:%d", port);
 
@@ -137,7 +139,7 @@ TEST(PREFETCH, CPU) {
     std::string in_var_name("ids");
     std::string out_var_name("out");
 
-    client->AsyncPrefetchVariable(ep, ctx, scope, in_var_name, out_var_name);
+    client->AsyncPrefetchVar(ep, ctx, scope, in_var_name, out_var_name);
     client->Wait();
     auto var = scope.Var(out_var_name);
     auto value = var->GetMutable<framework::SelectedRows>()->value();

paddle/fluid/operators/detail/rpc_client.cc

+// Copyright (c) 2018 PaddlePaddle Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "paddle/fluid/operators/detail/rpc_client.h"
+
+namespace paddle {
+namespace operators {
+namespace detail {
+
+std::once_flag RPCClient::init_flag_;
+std::unique_ptr<RPCClient> RPCClient::rpc_client_(nullptr);
+
+}  // namespace detail
+}  // namespace operators
+}  // namespace paddle

paddle/fluid/operators/detail/rpc_client.h

+// Copyright (c) 2018 PaddlePaddle Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#pragma once
+
+#include <string>
+
+#include "paddle/fluid/framework/data_type.h"
+#include "paddle/fluid/framework/lod_tensor.h"
+#include "paddle/fluid/framework/scope.h"
+
+namespace paddle {
+namespace operators {
+namespace detail {
+
+class RPCClient {
+ public:
+  virtual bool AsyncSendVar(const std::string& ep,
+                            const platform::DeviceContext& ctx,
+                            const framework::Scope& scope,
+                            const std::string& var_name,
+                            int64_t time_out = rpc_time_out) = 0;
+
+  virtual bool AsyncGetVar(const std::string& ep,
+                           const platform::DeviceContext& ctx,
+                           const framework::Scope& scope,
+                           const std::string& var_name,
+                           int64_t time_out = rpc_time_out) = 0;
+
+  virtual bool AsyncPrefetchVar(const std::string& ep,
+                                const platform::DeviceContext& ctx,
+                                const framework::Scope& scope,
+                                const std::string& in_var_name,
+                                const std::string& out_var_name,
+                                int64_t time_out = rpc_time_out) = 0;
+
+  virtual void AsyncSendBatchBarrier(const std::string& ep,
+                                     int64_t time_out = rpc_time_out) = 0;
+
+  virtual void AsyncSendFetchBarrier(const std::string& ep,
+                                     int64_t time_out = rpc_time_out) = 0;
+
+  virtual void Wait() = 0;
+
+  static constexpr int64_t rpc_time_out = 120 * 1000;
+
+  template <typename T>
+  static RPCClient* GetInstance() {
+    std::call_once(init_flag_, &RPCClient::Init<T>);
+    return rpc_client_.get();
+  }
+
+  // Init is called by GetInstance.
+  template <typename T>
+  static void Init() {
+    if (rpc_client_.get() == nullptr) {
+      rpc_client_.reset(new T());
+      rpc_client_->InitImpl();
+    }
+  }
+
+ protected:
+  virtual void InitImpl() {}
+
+ private:
+  static std::once_flag init_flag_;
+  static std::unique_ptr<RPCClient> rpc_client_;
+};
+}  // namespace detail
+}  // namespace operators
+}  // namespace paddle

paddle/fluid/operators/fetch_barrier_op.cc

@@ -21,6 +21,7 @@ limitations under the License. */
 #include "paddle/fluid/framework/op_registry.h"
 
 #include "paddle/fluid/operators/detail/grpc_client.h"
+#include "paddle/fluid/operators/detail/rpc_client.h"
 #include "paddle/fluid/platform/profiler.h"
 
 namespace paddle {
@@ -43,7 +44,8 @@ class FetchBarrierOp : public framework::OperatorBase {
     // For profiling
     platform::RecordEvent record_event(Type(), &ctx);
 
-    auto rpc_client = detail::RPCClient::GetInstance();
+    detail::RPCClient* rpc_client =
+        detail::RPCClient::GetInstance<detail::GRPCClient>();
 
     rpc_client->Wait();
 

paddle/fluid/operators/gen_nccl_id_op.cc

@@ -61,12 +61,13 @@ class GenNCCLIdOp : public framework::OperatorBase {
 
     std::vector<std::string> endpoint_list =
         Attr<std::vector<std::string>>("endpoint_list");
-    detail::RPCClient client;
+    detail::RPCClient* client =
+        detail::RPCClient::GetInstance<detail::GRPCClient>();
     for (auto& ep : endpoint_list) {
       VLOG(3) << "sending nccl id to " << ep;
-      client.AsyncSendVariable(ep, dev_ctx, *scope, NCCL_ID_VARNAME);
+      client->AsyncSendVar(ep, dev_ctx, *scope, NCCL_ID_VARNAME);
     }
-    client.Wait();
+    client->Wait();
     VLOG(3) << "sending completed...";
   }
 

paddle/fluid/operators/prefetch_op.cc

@@ -41,14 +41,14 @@ class PrefetchOp : public framework::OperatorBase {
     platform::DeviceContextPool& pool = platform::DeviceContextPool::Instance();
     auto& ctx = *pool.Get(place);
 
-    auto rpc_client = detail::RPCClient::GetInstance();
+    detail::RPCClient* rpc_client =
+        detail::RPCClient::GetInstance<detail::GRPCClient>();
 
     for (size_t i = 0; i < ins.size(); i++) {
       if (NeedSend(scope, ins[i])) {
         VLOG(3) << "sending " << ins[i] << " to " << epmap[i] << " to get "
                 << outs[i] << " back";
-        rpc_client->AsyncPrefetchVariable(epmap[i], ctx, scope, ins[i],
-                                          outs[i]);
+        rpc_client->AsyncPrefetchVar(epmap[i], ctx, scope, ins[i], outs[i]);
       } else {
         VLOG(3) << "don't send no-initialied variable: " << ins[i];
       }

paddle/fluid/operators/recv_op.cc

@@ -44,11 +44,12 @@ class RecvOp : public framework::OperatorBase {
     // For profiling
     platform::RecordEvent record_event(Type(), &ctx);
 
-    auto rpc_client = detail::RPCClient::GetInstance();
+    detail::RPCClient* rpc_client =
+        detail::RPCClient::GetInstance<detail::GRPCClient>();
 
     for (size_t i = 0; i < outs.size(); i++) {
       VLOG(3) << "getting " << outs[i] << " from " << epmap[i];
-      rpc_client->AsyncGetVariable(epmap[i], ctx, scope, outs[i]);
+      rpc_client->AsyncGetVar(epmap[i], ctx, scope, outs[i]);
     }
     if (sync_mode) {
       rpc_client->Wait();

paddle/fluid/operators/send_barrier_op.cc

@@ -44,7 +44,8 @@ class SendBarrierOp : public framework::OperatorBase {
     // For profiling
     platform::RecordEvent record_event(Type(), &ctx);
 
-    auto rpc_client = detail::RPCClient::GetInstance();
+    detail::RPCClient* rpc_client =
+        detail::RPCClient::GetInstance<detail::GRPCClient>();
 
     VLOG(3) << "SendBarrierOp sync_mode:" << sync_mode;
 

paddle/fluid/operators/send_op.cc

@@ -49,12 +49,13 @@ class SendOp : public framework::OperatorBase {
     // For profiling
     platform::RecordEvent record_event(Type(), &ctx);
 
-    auto rpc_client = detail::RPCClient::GetInstance();
+    detail::RPCClient* rpc_client =
+        detail::RPCClient::GetInstance<detail::GRPCClient>();
 
     for (size_t i = 0; i < ins.size(); i++) {
       if (NeedSend(scope, ins[i])) {
         VLOG(3) << "sending " << ins[i] << " to " << epmap[i];
-        rpc_client->AsyncSendVariable(epmap[i], ctx, scope, ins[i]);
+        rpc_client->AsyncSendVar(epmap[i], ctx, scope, ins[i]);
       } else {
         VLOG(3) << "don't send no-initialied variable: " << ins[i];
       }
@@ -72,7 +73,7 @@ class SendOp : public framework::OperatorBase {
     if (outs.size() > 0) {
       for (size_t i = 0; i < outs.size(); i++) {
         VLOG(2) << "getting " << outs[i] << " from " << epmap[i];
-        rpc_client->AsyncGetVariable(epmap[i], ctx, scope, outs[i]);
+        rpc_client->AsyncGetVar(epmap[i], ctx, scope, outs[i]);
       }
       rpc_client->Wait();
       // tell pservers that current trainer have called fetch

paddle/fluid/operators/send_vars_op.cc

@@ -45,14 +45,15 @@ class SendVarsOp : public framework::OperatorBase {
     // For profiling
     platform::RecordEvent record_event(Type(), &ctx);
 
-    auto rpc_client = detail::RPCClient::GetInstance();
+    detail::RPCClient* rpc_client =
+        detail::RPCClient::GetInstance<detail::GRPCClient>();
 
     for (size_t i = 0; i < ins.size(); i++) {
       if (NeedSend(scope, ins[i])) {
         VLOG(3) << "sending " << ins[i] << " to " << epmap[i];
         // TODO(Yancey1989): we need to use an IO threadpool which has
         // a larger number of threads than the computing threadpool.
-        rpc_client->AsyncSendVariable(epmap[i], ctx, scope, ins[i]);
+        rpc_client->AsyncSendVar(epmap[i], ctx, scope, ins[i]);
       } else {
         VLOG(3) << "don't send no-initialied variable: " << ins[i];
       }

paddle/fluid/operators/test_send_nccl_id.cc

@@ -87,9 +87,10 @@ TEST(SendNcclId, GrpcServer) {
   int port = g_rpc_service->GetSelectedPort();
 
   std::string ep = string::Sprintf("127.0.0.1:%d", port);
-  detail::RPCClient* client = detail::RPCClient::GetInstance();
-  LOG(INFO) << "connect to server " << ep;
-  client->AsyncSendVariable(ep, dev_ctx, scope, NCCL_ID_VARNAME);
+  detail::RPCClient* client =
+      detail::RPCClient::GetInstance<detail::GRPCClient>();
+  LOG(INFO) << "connect to server" << ep;
+  client->AsyncSendVar(ep, dev_ctx, scope, NCCL_ID_VARNAME);
   client->Wait();
   client->AsyncSendBatchBarrier(ep);
   client->Wait();