1 /* Copyright 2016 The TensorFlow Authors. All Rights Reserved. 2 3 Licensed under the Apache License, Version 2.0 (the "License"); 4 you may not use this file except in compliance with the License. 5 You may obtain a copy of the License at 6 7 http://www.apache.org/licenses/LICENSE-2.0 8 9 Unless required by applicable law or agreed to in writing, software 10 distributed under the License is distributed on an "AS IS" BASIS, 11 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 See the License for the specific language governing permissions and 13 limitations under the License. 14 ==============================================================================*/ 15 16 #ifndef TENSORFLOW_CORE_DISTRIBUTED_RUNTIME_SERVER_LIB_H_ 17 #define TENSORFLOW_CORE_DISTRIBUTED_RUNTIME_SERVER_LIB_H_ 18 19 #include <memory> 20 21 #include "tensorflow/core/lib/core/status.h" 22 #include "tensorflow/core/platform/macros.h" 23 #include "tensorflow/core/protobuf/tensorflow_server.pb.h" 24 25 namespace tensorflow { 26 27 // This library supports a registration/factory-based mechanism for 28 // creating TensorFlow server objects. Each server implementation must 29 // have an accompanying implementation of ServerFactory, and create a 30 // static "registrar" object that calls `ServerFactory::Register()` 31 // with an instance of the factory class. See "rpc/grpc_server_lib.cc" 32 // for an example. 33 34 // Represents a single TensorFlow server that exports Master and Worker 35 // services. 36 class ServerInterface { 37 public: 38 ServerInterface() {} 39 virtual ~ServerInterface() {} 40 41 // Starts the server running asynchronously. Returns OK on success, otherwise 42 // returns an error. 43 virtual Status Start() = 0; 44 45 // Stops the server asynchronously. Returns OK on success, otherwise returns 46 // an error. 47 // 48 // After calling `Stop()`, the caller may call `Join()` to block until the 49 // server has stopped. 50 virtual Status Stop() = 0; 51 52 // Blocks until the server has stopped. Returns OK on success, otherwise 53 // returns an error. 54 virtual Status Join() = 0; 55 56 // Returns a target string that can be used to connect to this server using 57 // `tensorflow::NewSession()`. 58 virtual const string target() const = 0; 59 60 private: 61 TF_DISALLOW_COPY_AND_ASSIGN(ServerInterface); 62 }; 63 64 class ServerFactory { 65 public: 66 // Creates a new server based on the given `server_def`, and stores 67 // it in `*out_server`. Returns OK on success, otherwise returns an 68 // error. 69 virtual Status NewServer(const ServerDef& server_def, 70 std::unique_ptr<ServerInterface>* out_server) = 0; 71 72 // Returns true if and only if this factory can create a server 73 // based on the given `server_def`. 74 virtual bool AcceptsOptions(const ServerDef& server_def) = 0; 75 76 virtual ~ServerFactory() {} 77 78 // For each `ServerFactory` subclass, an instance of that class must 79 // be registered by calling this method. 80 // 81 // The `server_type` must be unique to the server factory. 82 static void Register(const string& server_type, ServerFactory* factory); 83 84 // Looks up a factory that can create a server based on the given 85 // `server_def`, and stores it in `*out_factory`. Returns OK on 86 // success, otherwise returns an error. 87 static Status GetFactory(const ServerDef& server_def, 88 ServerFactory** out_factory); 89 }; 90 91 // Creates a server based on the given `server_def`, and stores it in 92 // `*out_server`. Returns OK on success, otherwise returns an error. 93 Status NewServer(const ServerDef& server_def, 94 std::unique_ptr<ServerInterface>* out_server); 95 96 } // namespace tensorflow 97 98 #endif // TENSORFLOW_CORE_DISTRIBUTED_RUNTIME_SERVER_LIB_H_ 99
