1 /* 2 * 3 * Copyright 2019 gRPC authors. 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 * 17 */ 18 19 #ifndef GRPCPP_IMPL_CODEGEN_SERVER_CONTEXT_IMPL_H 20 #define GRPCPP_IMPL_CODEGEN_SERVER_CONTEXT_IMPL_H 21 22 #include <atomic> 23 #include <cassert> 24 #include <map> 25 #include <memory> 26 #include <type_traits> 27 #include <vector> 28 29 #include <grpc/impl/codegen/port_platform.h> 30 31 #include <grpc/impl/codegen/compression_types.h> 32 #include <grpcpp/impl/codegen/call.h> 33 #include <grpcpp/impl/codegen/call_op_set.h> 34 #include <grpcpp/impl/codegen/callback_common.h> 35 #include <grpcpp/impl/codegen/completion_queue_tag.h> 36 #include <grpcpp/impl/codegen/config.h> 37 #include <grpcpp/impl/codegen/create_auth_context.h> 38 #include <grpcpp/impl/codegen/message_allocator.h> 39 #include <grpcpp/impl/codegen/metadata_map.h> 40 #include <grpcpp/impl/codegen/security/auth_context.h> 41 #include <grpcpp/impl/codegen/server_callback_impl.h> 42 #include <grpcpp/impl/codegen/server_interceptor.h> 43 #include <grpcpp/impl/codegen/status.h> 44 #include <grpcpp/impl/codegen/string_ref.h> 45 #include <grpcpp/impl/codegen/time.h> 46 47 struct grpc_metadata; 48 struct grpc_call; 49 struct census_context; 50 51 namespace grpc_impl { 52 class ClientContext; 53 class CompletionQueue; 54 class Server; 55 template <class W, class R> 56 class ServerAsyncReader; 57 template <class W> 58 class ServerAsyncWriter; 59 template <class W> 60 class ServerAsyncResponseWriter; 61 template <class W, class R> 62 class ServerAsyncReaderWriter; 63 template <class R> 64 class ServerReader; 65 template <class W> 66 class ServerWriter; 67 68 namespace internal { 69 template <class ServiceType, class RequestType, class ResponseType> 70 class BidiStreamingHandler; 71 template <class RequestType, class ResponseType> 72 class CallbackUnaryHandler; 73 template <class RequestType, class ResponseType> 74 class CallbackClientStreamingHandler; 75 template <class RequestType, class ResponseType> 76 class CallbackServerStreamingHandler; 77 template <class RequestType, class ResponseType> 78 class CallbackBidiHandler; 79 template <class ServiceType, class RequestType, class ResponseType> 80 class ClientStreamingHandler; 81 template <class ServiceType, class RequestType, class ResponseType> 82 class RpcMethodHandler; 83 template <class Base> 84 class FinishOnlyReactor; 85 template <class W, class R> 86 class ServerReaderWriterBody; 87 template <class ServiceType, class RequestType, class ResponseType> 88 class ServerStreamingHandler; 89 class ServerReactor; 90 template <class Streamer, bool WriteNeeded> 91 class TemplatedBidiStreamingHandler; 92 template <::grpc::StatusCode code> 93 class ErrorMethodHandler; 94 } // namespace internal 95 96 } // namespace grpc_impl 97 namespace grpc { 98 class GenericServerContext; 99 class ServerInterface; 100 101 #ifndef GRPC_CALLBACK_API_NONEXPERIMENTAL 102 namespace experimental { 103 #endif 104 class GenericCallbackServerContext; 105 #ifndef GRPC_CALLBACK_API_NONEXPERIMENTAL 106 } // namespace experimental 107 #endif 108 namespace internal { 109 class Call; 110 } // namespace internal 111 112 namespace testing { 113 class InteropServerContextInspector; 114 class ServerContextTestSpouse; 115 class DefaultReactorTestPeer; 116 } // namespace testing 117 118 } // namespace grpc 119 120 namespace grpc_impl { 121 122 /// Base class of ServerContext. Experimental until callback API is final. 123 class ServerContextBase { 124 public: 125 virtual ~ServerContextBase(); 126 127 /// Return the deadline for the server call. deadline()128 std::chrono::system_clock::time_point deadline() const { 129 return ::grpc::Timespec2Timepoint(deadline_); 130 } 131 132 /// Return a \a gpr_timespec representation of the server call's deadline. raw_deadline()133 gpr_timespec raw_deadline() const { return deadline_; } 134 135 /// Add the (\a key, \a value) pair to the initial metadata 136 /// associated with a server call. These are made available at the client side 137 /// by the \a grpc::ClientContext::GetServerInitialMetadata() method. 138 /// 139 /// \warning This method should only be called before sending initial metadata 140 /// to the client (which can happen explicitly, or implicitly when sending a 141 /// a response message or status to the client). 142 /// 143 /// \param key The metadata key. If \a value is binary data, it must 144 /// end in "-bin". 145 /// \param value The metadata value. If its value is binary, the key name 146 /// must end in "-bin". 147 /// 148 /// Metadata must conform to the following format: 149 /// Custom-Metadata -> Binary-Header / ASCII-Header 150 /// Binary-Header -> {Header-Name "-bin" } {binary value} 151 /// ASCII-Header -> Header-Name ASCII-Value 152 /// Header-Name -> 1*( %x30-39 / %x61-7A / "_" / "-" / ".") ; 0-9 a-z _ - . 153 /// ASCII-Value -> 1*( %x20-%x7E ) ; space and printable ASCII 154 void AddInitialMetadata(const grpc::string& key, const grpc::string& value); 155 156 /// Add the (\a key, \a value) pair to the initial metadata 157 /// associated with a server call. These are made available at the client 158 /// side by the \a grpc::ClientContext::GetServerTrailingMetadata() method. 159 /// 160 /// \warning This method should only be called before sending trailing 161 /// metadata to the client (which happens when the call is finished and a 162 /// status is sent to the client). 163 /// 164 /// \param key The metadata key. If \a value is binary data, 165 /// it must end in "-bin". 166 /// \param value The metadata value. If its value is binary, the key name 167 /// must end in "-bin". 168 /// 169 /// Metadata must conform to the following format: 170 /// Custom-Metadata -> Binary-Header / ASCII-Header 171 /// Binary-Header -> {Header-Name "-bin" } {binary value} 172 /// ASCII-Header -> Header-Name ASCII-Value 173 /// Header-Name -> 1*( %x30-39 / %x61-7A / "_" / "-" / ".") ; 0-9 a-z _ - . 174 /// ASCII-Value -> 1*( %x20-%x7E ) ; space and printable ASCII 175 void AddTrailingMetadata(const grpc::string& key, const grpc::string& value); 176 177 /// IsCancelled is always safe to call when using sync or callback API. 178 /// When using async API, it is only safe to call IsCancelled after 179 /// the AsyncNotifyWhenDone tag has been delivered. Thread-safe. 180 bool IsCancelled() const; 181 182 /// Cancel the Call from the server. This is a best-effort API and 183 /// depending on when it is called, the RPC may still appear successful to 184 /// the client. 185 /// For example, if TryCancel() is called on a separate thread, it might race 186 /// with the server handler which might return success to the client before 187 /// TryCancel() was even started by the thread. 188 /// 189 /// It is the caller's responsibility to prevent such races and ensure that if 190 /// TryCancel() is called, the serverhandler must return Status::CANCELLED. 191 /// The only exception is that if the serverhandler is already returning an 192 /// error status code, it is ok to not return Status::CANCELLED even if 193 /// TryCancel() was called. 194 /// 195 /// Note that TryCancel() does not change any of the tags that are pending 196 /// on the completion queue. All pending tags will still be delivered 197 /// (though their ok result may reflect the effect of cancellation). 198 void TryCancel() const; 199 200 /// Return a collection of initial metadata key-value pairs sent from the 201 /// client. Note that keys may happen more than 202 /// once (ie, a \a std::multimap is returned). 203 /// 204 /// It is safe to use this method after initial metadata has been received, 205 /// Calls always begin with the client sending initial metadata, so this is 206 /// safe to access as soon as the call has begun on the server side. 207 /// 208 /// \return A multimap of initial metadata key-value pairs from the server. client_metadata()209 const std::multimap<grpc::string_ref, grpc::string_ref>& client_metadata() 210 const { 211 return *client_metadata_.map(); 212 } 213 214 /// Return the compression algorithm to be used by the server call. compression_level()215 grpc_compression_level compression_level() const { 216 return compression_level_; 217 } 218 219 /// Set \a level to be the compression level used for the server call. 220 /// 221 /// \param level The compression level used for the server call. set_compression_level(grpc_compression_level level)222 void set_compression_level(grpc_compression_level level) { 223 compression_level_set_ = true; 224 compression_level_ = level; 225 } 226 227 /// Return a bool indicating whether the compression level for this call 228 /// has been set (either implicitly or through a previous call to 229 /// \a set_compression_level. compression_level_set()230 bool compression_level_set() const { return compression_level_set_; } 231 232 /// Return the compression algorithm the server call will request be used. 233 /// Note that the gRPC runtime may decide to ignore this request, for example, 234 /// due to resource constraints, or if the server is aware the client doesn't 235 /// support the requested algorithm. compression_algorithm()236 grpc_compression_algorithm compression_algorithm() const { 237 return compression_algorithm_; 238 } 239 /// Set \a algorithm to be the compression algorithm used for the server call. 240 /// 241 /// \param algorithm The compression algorithm used for the server call. 242 void set_compression_algorithm(grpc_compression_algorithm algorithm); 243 244 /// Set the serialized load reporting costs in \a cost_data for the call. 245 void SetLoadReportingCosts(const std::vector<grpc::string>& cost_data); 246 247 /// Return the authentication context for this server call. 248 /// 249 /// \see grpc::AuthContext. auth_context()250 std::shared_ptr<const ::grpc::AuthContext> auth_context() const { 251 if (auth_context_.get() == nullptr) { 252 auth_context_ = ::grpc::CreateAuthContext(call_); 253 } 254 return auth_context_; 255 } 256 257 /// Return the peer uri in a string. 258 /// WARNING: this value is never authenticated or subject to any security 259 /// related code. It must not be used for any authentication related 260 /// functionality. Instead, use auth_context. 261 grpc::string peer() const; 262 263 /// Get the census context associated with this server call. 264 const struct census_context* census_context() const; 265 266 /// Should be used for framework-level extensions only. 267 /// Applications never need to call this method. c_call()268 grpc_call* c_call() { return call_; } 269 270 protected: 271 /// Async only. Has to be called before the rpc starts. 272 /// Returns the tag in completion queue when the rpc finishes. 273 /// IsCancelled() can then be called to check whether the rpc was cancelled. 274 /// TODO(vjpai): Fix this so that the tag is returned even if the call never 275 /// starts (https://github.com/grpc/grpc/issues/10136). AsyncNotifyWhenDone(void * tag)276 void AsyncNotifyWhenDone(void* tag) { 277 has_notify_when_done_tag_ = true; 278 async_notify_when_done_tag_ = tag; 279 } 280 281 /// NOTE: This is an API for advanced users who need custom allocators. 282 /// Get and maybe mutate the allocator state associated with the current RPC. 283 /// Currently only applicable for callback unary RPC methods. 284 /// WARNING: This is experimental API and could be changed or removed. GetRpcAllocatorState()285 ::grpc::experimental::RpcAllocatorState* GetRpcAllocatorState() { 286 return message_allocator_state_; 287 } 288 289 /// Get a library-owned default unary reactor for use in minimal reaction 290 /// cases. This supports typical unary RPC usage of providing a response and 291 /// status. It supports immediate Finish (finish from within the method 292 /// handler) or delayed Finish (finish called after the method handler 293 /// invocation). It does not support reacting to cancellation or completion, 294 /// or early sending of initial metadata. Since this is a library-owned 295 /// reactor, it should not be delete'd or freed in any way. This is more 296 /// efficient than creating a user-owned reactor both because of avoiding an 297 /// allocation and because its minimal reactions are optimized using a core 298 /// surface flag that allows their reactions to run inline without any 299 /// thread-hop. 300 /// 301 /// This method should not be called more than once or called after return 302 /// from the method handler. 303 /// 304 /// WARNING: This is experimental API and could be changed or removed. DefaultReactor()305 ::grpc_impl::ServerUnaryReactor* DefaultReactor() { 306 // Short-circuit the case where a default reactor was already set up by 307 // the TestPeer. 308 if (test_unary_ != nullptr) { 309 return reinterpret_cast<Reactor*>(&default_reactor_); 310 } 311 new (&default_reactor_) Reactor; 312 #ifndef NDEBUG 313 bool old = false; 314 assert(default_reactor_used_.compare_exchange_strong( 315 old, true, std::memory_order_relaxed)); 316 #else 317 default_reactor_used_.store(true, std::memory_order_relaxed); 318 #endif 319 return reinterpret_cast<Reactor*>(&default_reactor_); 320 } 321 322 /// Constructors for use by derived classes 323 ServerContextBase(); 324 ServerContextBase(gpr_timespec deadline, grpc_metadata_array* arr); 325 326 private: 327 friend class ::grpc::testing::InteropServerContextInspector; 328 friend class ::grpc::testing::ServerContextTestSpouse; 329 friend class ::grpc::testing::DefaultReactorTestPeer; 330 friend class ::grpc::ServerInterface; 331 friend class ::grpc_impl::Server; 332 template <class W, class R> 333 friend class ::grpc_impl::ServerAsyncReader; 334 template <class W> 335 friend class ::grpc_impl::ServerAsyncWriter; 336 template <class W> 337 friend class ::grpc_impl::ServerAsyncResponseWriter; 338 template <class W, class R> 339 friend class ::grpc_impl::ServerAsyncReaderWriter; 340 template <class R> 341 friend class ::grpc_impl::ServerReader; 342 template <class W> 343 friend class ::grpc_impl::ServerWriter; 344 template <class W, class R> 345 friend class ::grpc_impl::internal::ServerReaderWriterBody; 346 template <class ServiceType, class RequestType, class ResponseType> 347 friend class ::grpc_impl::internal::RpcMethodHandler; 348 template <class ServiceType, class RequestType, class ResponseType> 349 friend class ::grpc_impl::internal::ClientStreamingHandler; 350 template <class ServiceType, class RequestType, class ResponseType> 351 friend class ::grpc_impl::internal::ServerStreamingHandler; 352 template <class Streamer, bool WriteNeeded> 353 friend class ::grpc_impl::internal::TemplatedBidiStreamingHandler; 354 template <class RequestType, class ResponseType> 355 friend class ::grpc_impl::internal::CallbackUnaryHandler; 356 template <class RequestType, class ResponseType> 357 friend class ::grpc_impl::internal::CallbackClientStreamingHandler; 358 template <class RequestType, class ResponseType> 359 friend class ::grpc_impl::internal::CallbackServerStreamingHandler; 360 template <class RequestType, class ResponseType> 361 friend class ::grpc_impl::internal::CallbackBidiHandler; 362 template <::grpc::StatusCode code> 363 friend class ::grpc_impl::internal::ErrorMethodHandler; 364 template <class Base> 365 friend class ::grpc_impl::internal::FinishOnlyReactor; 366 friend class ::grpc_impl::ClientContext; 367 friend class ::grpc::GenericServerContext; 368 #ifdef GRPC_CALLBACK_API_NONEXPERIMENTAL 369 friend class ::grpc::GenericCallbackServerContext; 370 #else 371 friend class ::grpc::experimental::GenericCallbackServerContext; 372 #endif 373 374 /// Prevent copying. 375 ServerContextBase(const ServerContextBase&); 376 ServerContextBase& operator=(const ServerContextBase&); 377 378 class CompletionOp; 379 380 void BeginCompletionOp( 381 ::grpc::internal::Call* call, std::function<void(bool)> callback, 382 ::grpc_impl::internal::ServerCallbackCall* callback_controller); 383 /// Return the tag queued by BeginCompletionOp() 384 ::grpc::internal::CompletionQueueTag* GetCompletionOpTag(); 385 set_call(grpc_call * call)386 void set_call(grpc_call* call) { call_ = call; } 387 388 void BindDeadlineAndMetadata(gpr_timespec deadline, grpc_metadata_array* arr); 389 390 void Clear(); 391 392 void Setup(gpr_timespec deadline); 393 initial_metadata_flags()394 uint32_t initial_metadata_flags() const { return 0; } 395 set_server_rpc_info(const char * method,::grpc::internal::RpcMethod::RpcType type,const std::vector<std::unique_ptr<::grpc::experimental::ServerInterceptorFactoryInterface>> & creators)396 ::grpc::experimental::ServerRpcInfo* set_server_rpc_info( 397 const char* method, ::grpc::internal::RpcMethod::RpcType type, 398 const std::vector<std::unique_ptr< 399 ::grpc::experimental::ServerInterceptorFactoryInterface>>& creators) { 400 if (creators.size() != 0) { 401 rpc_info_ = new ::grpc::experimental::ServerRpcInfo(this, method, type); 402 rpc_info_->RegisterInterceptors(creators); 403 } 404 return rpc_info_; 405 } 406 set_message_allocator_state(::grpc::experimental::RpcAllocatorState * allocator_state)407 void set_message_allocator_state( 408 ::grpc::experimental::RpcAllocatorState* allocator_state) { 409 message_allocator_state_ = allocator_state; 410 } 411 412 CompletionOp* completion_op_; 413 bool has_notify_when_done_tag_; 414 void* async_notify_when_done_tag_; 415 ::grpc::internal::CallbackWithSuccessTag completion_tag_; 416 417 gpr_timespec deadline_; 418 grpc_call* call_; 419 ::grpc_impl::CompletionQueue* cq_; 420 bool sent_initial_metadata_; 421 mutable std::shared_ptr<const ::grpc::AuthContext> auth_context_; 422 mutable ::grpc::internal::MetadataMap client_metadata_; 423 std::multimap<grpc::string, grpc::string> initial_metadata_; 424 std::multimap<grpc::string, grpc::string> trailing_metadata_; 425 426 bool compression_level_set_; 427 grpc_compression_level compression_level_; 428 grpc_compression_algorithm compression_algorithm_; 429 430 ::grpc::internal::CallOpSet<::grpc::internal::CallOpSendInitialMetadata, 431 ::grpc::internal::CallOpSendMessage> 432 pending_ops_; 433 bool has_pending_ops_; 434 435 ::grpc::experimental::ServerRpcInfo* rpc_info_; 436 ::grpc::experimental::RpcAllocatorState* message_allocator_state_ = nullptr; 437 438 class Reactor : public ServerUnaryReactor { 439 public: OnCancel()440 void OnCancel() override {} OnDone()441 void OnDone() override {} 442 // Override InternalInlineable for this class since its reactions are 443 // trivial and thus do not need to be run from the executor (triggering a 444 // thread hop). This should only be used by internal reactors (thus the 445 // name) and not by user application code. InternalInlineable()446 bool InternalInlineable() override { return true; } 447 }; 448 SetupTestDefaultReactor(std::function<void (::grpc::Status)> func)449 void SetupTestDefaultReactor(std::function<void(::grpc::Status)> func) { 450 test_unary_.reset(new TestServerCallbackUnary(this, std::move(func))); 451 } test_status_set()452 bool test_status_set() const { 453 return (test_unary_ != nullptr) && test_unary_->status_set(); 454 } test_status()455 ::grpc::Status test_status() const { return test_unary_->status(); } 456 457 class TestServerCallbackUnary : public ::grpc_impl::ServerCallbackUnary { 458 public: TestServerCallbackUnary(ServerContextBase * ctx,std::function<void (::grpc::Status)> func)459 TestServerCallbackUnary(ServerContextBase* ctx, 460 std::function<void(::grpc::Status)> func) 461 : reactor_(ctx->DefaultReactor()), func_(std::move(func)) { 462 this->BindReactor(reactor_); 463 } Finish(::grpc::Status s)464 void Finish(::grpc::Status s) override { 465 status_ = s; 466 func_(std::move(s)); 467 status_set_.store(true, std::memory_order_release); 468 } SendInitialMetadata()469 void SendInitialMetadata() override {} 470 status_set()471 bool status_set() const { 472 return status_set_.load(std::memory_order_acquire); 473 } status()474 ::grpc::Status status() const { return status_; } 475 476 private: CallOnDone()477 void CallOnDone() override {} reactor()478 ::grpc_impl::internal::ServerReactor* reactor() override { 479 return reactor_; 480 } 481 482 ::grpc_impl::ServerUnaryReactor* const reactor_; 483 std::atomic_bool status_set_{false}; 484 ::grpc::Status status_; 485 const std::function<void(::grpc::Status s)> func_; 486 }; 487 488 typename std::aligned_storage<sizeof(Reactor), alignof(Reactor)>::type 489 default_reactor_; 490 std::atomic_bool default_reactor_used_{false}; 491 std::unique_ptr<TestServerCallbackUnary> test_unary_; 492 }; 493 494 /// A ServerContext or CallbackServerContext allows the code implementing a 495 /// service handler to: 496 /// 497 /// - Add custom initial and trailing metadata key-value pairs that will 498 /// propagated to the client side. 499 /// - Control call settings such as compression and authentication. 500 /// - Access metadata coming from the client. 501 /// - Get performance metrics (ie, census). 502 /// 503 /// Context settings are only relevant to the call handler they are supplied to, 504 /// that is to say, they aren't sticky across multiple calls. Some of these 505 /// settings, such as the compression options, can be made persistent at server 506 /// construction time by specifying the appropriate \a ChannelArguments 507 /// to a \a grpc::ServerBuilder, via \a ServerBuilder::AddChannelArgument. 508 /// 509 /// \warning ServerContext instances should \em not be reused across rpcs. 510 class ServerContext : public ServerContextBase { 511 public: ServerContext()512 ServerContext() {} // for async calls 513 514 using ServerContextBase::AddInitialMetadata; 515 using ServerContextBase::AddTrailingMetadata; 516 using ServerContextBase::auth_context; 517 using ServerContextBase::c_call; 518 using ServerContextBase::census_context; 519 using ServerContextBase::client_metadata; 520 using ServerContextBase::compression_algorithm; 521 using ServerContextBase::compression_level; 522 using ServerContextBase::compression_level_set; 523 using ServerContextBase::deadline; 524 using ServerContextBase::IsCancelled; 525 using ServerContextBase::peer; 526 using ServerContextBase::raw_deadline; 527 using ServerContextBase::set_compression_algorithm; 528 using ServerContextBase::set_compression_level; 529 using ServerContextBase::SetLoadReportingCosts; 530 using ServerContextBase::TryCancel; 531 532 // Sync/CQ-based Async ServerContext only 533 using ServerContextBase::AsyncNotifyWhenDone; 534 535 private: 536 // Constructor for internal use by server only 537 friend class ::grpc_impl::Server; ServerContext(gpr_timespec deadline,grpc_metadata_array * arr)538 ServerContext(gpr_timespec deadline, grpc_metadata_array* arr) 539 : ServerContextBase(deadline, arr) {} 540 541 // CallbackServerContext only 542 using ServerContextBase::DefaultReactor; 543 using ServerContextBase::GetRpcAllocatorState; 544 545 /// Prevent copying. 546 ServerContext(const ServerContext&) = delete; 547 ServerContext& operator=(const ServerContext&) = delete; 548 }; 549 550 class CallbackServerContext : public ServerContextBase { 551 public: 552 /// Public constructors are for direct use only by mocking tests. In practice, 553 /// these objects will be owned by the library. CallbackServerContext()554 CallbackServerContext() {} 555 556 using ServerContextBase::AddInitialMetadata; 557 using ServerContextBase::AddTrailingMetadata; 558 using ServerContextBase::auth_context; 559 using ServerContextBase::c_call; 560 using ServerContextBase::census_context; 561 using ServerContextBase::client_metadata; 562 using ServerContextBase::compression_algorithm; 563 using ServerContextBase::compression_level; 564 using ServerContextBase::compression_level_set; 565 using ServerContextBase::deadline; 566 using ServerContextBase::IsCancelled; 567 using ServerContextBase::peer; 568 using ServerContextBase::raw_deadline; 569 using ServerContextBase::set_compression_algorithm; 570 using ServerContextBase::set_compression_level; 571 using ServerContextBase::SetLoadReportingCosts; 572 using ServerContextBase::TryCancel; 573 574 // CallbackServerContext only 575 using ServerContextBase::DefaultReactor; 576 using ServerContextBase::GetRpcAllocatorState; 577 578 private: 579 // Sync/CQ-based Async ServerContext only 580 using ServerContextBase::AsyncNotifyWhenDone; 581 582 /// Prevent copying. 583 CallbackServerContext(const CallbackServerContext&) = delete; 584 CallbackServerContext& operator=(const CallbackServerContext&) = delete; 585 }; 586 587 } // namespace grpc_impl 588 589 static_assert(std::is_base_of<::grpc_impl::ServerContextBase, 590 ::grpc_impl::ServerContext>::value, 591 "improper base class"); 592 static_assert(std::is_base_of<::grpc_impl::ServerContextBase, 593 ::grpc_impl::CallbackServerContext>::value, 594 "improper base class"); 595 static_assert(sizeof(::grpc_impl::ServerContextBase) == 596 sizeof(::grpc_impl::ServerContext), 597 "wrong size"); 598 static_assert(sizeof(::grpc_impl::ServerContextBase) == 599 sizeof(::grpc_impl::CallbackServerContext), 600 "wrong size"); 601 602 #endif // GRPCPP_IMPL_CODEGEN_SERVER_CONTEXT_IMPL_H 603