server.h

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//
//
// Copyright 2015 gRPC authors.
//
// 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.
//
//
 
#ifndef GRPCPP_SERVER_H
#define GRPCPP_SERVER_H
 
#include <grpc/compression.h>
#include <grpc/event_engine/memory_allocator.h>
#include <grpc/support/atm.h>
#include <grpc/support/port_platform.h>
#include <grpcpp/channel.h>
#include <grpcpp/completion_queue.h>
#include <grpcpp/health_check_service_interface.h>
#include <grpcpp/impl/call.h>
#include <grpcpp/impl/grpc_library.h>
#include <grpcpp/impl/rpc_service_method.h>
#include <grpcpp/security/server_credentials.h>
#include <grpcpp/server_interface.h>
#include <grpcpp/support/channel_arguments.h>
#include <grpcpp/support/client_interceptor.h>
#include <grpcpp/support/config.h>
#include <grpcpp/support/status.h>
 
#include <list>
#include <memory>
#include <vector>
 
struct grpc_server;
 
namespace grpc {
class AsyncGenericService;
class ServerContext;
class ServerInitializer;
 
namespace internal {
class ExternalConnectionAcceptorImpl;
}  // namespace internal
 
class Server : public ServerInterface, private internal::GrpcLibrary {
 public:
  ~Server() ABSL_LOCKS_EXCLUDED(mu_) override;
 
  void Wait() ABSL_LOCKS_EXCLUDED(mu_) override;
 
  class GlobalCallbacks {
   public:
    virtual ~GlobalCallbacks() {}
    virtual void UpdateArguments(ChannelArguments* /*args*/) {}
    virtual void PreSynchronousRequest(ServerContext* context) = 0;
    virtual void PostSynchronousRequest(ServerContext* context) = 0;
    virtual void PreServerStart(Server* /*server*/) {}
    virtual void AddPort(Server* /*server*/, const std::string& /*addr*/,
                         ServerCredentials* /*creds*/, int /*port*/) {}
  };
  static void SetGlobalCallbacks(GlobalCallbacks* callbacks);
 
  grpc_server* c_server();
 
  HealthCheckServiceInterface* GetHealthCheckService() const {
    return health_check_service_.get();
  }
 
  std::shared_ptr<Channel> InProcessChannel(const ChannelArguments& args);
 
  class experimental_type {
   public:
    explicit experimental_type(Server* server) : server_(server) {}
 
    std::shared_ptr<Channel> InProcessChannelWithInterceptors(
        const ChannelArguments& args,
        std::vector<
            std::unique_ptr<experimental::ClientInterceptorFactoryInterface>>
            interceptor_creators);
 
   private:
    Server* server_;
  };
 
  experimental_type experimental() { return experimental_type(this); }
 
 protected:
  bool RegisterService(const std::string* addr, Service* service) override;
 
  int AddListeningPort(const std::string& addr,
                       ServerCredentials* creds) override;
 
  Server(ChannelArguments* args,
         std::shared_ptr<std::vector<std::unique_ptr<ServerCompletionQueue>>>
             sync_server_cqs,
         int min_pollers, int max_pollers, int sync_cq_timeout_msec,
         std::vector<std::shared_ptr<internal::ExternalConnectionAcceptorImpl>>
             acceptors,
         grpc_server_config_fetcher* server_config_fetcher = nullptr,
         grpc_resource_quota* server_rq = nullptr,
         std::vector<
             std::unique_ptr<experimental::ServerInterceptorFactoryInterface>>
             interceptor_creators = std::vector<std::unique_ptr<
                 experimental::ServerInterceptorFactoryInterface>>(),
         experimental::ServerMetricRecorder* server_metric_recorder = nullptr);
 
  void Start(ServerCompletionQueue** cqs, size_t num_cqs) override;
 
  grpc_server* server() override { return server_; }
 
  void set_health_check_service(
      std::unique_ptr<HealthCheckServiceInterface> service) {
    health_check_service_ = std::move(service);
  }
 
  ContextAllocator* context_allocator() { return context_allocator_.get(); }
 
  bool health_check_service_disabled() const {
    return health_check_service_disabled_;
  }
 
  grpc_event_engine::experimental::MemoryAllocator* memory_allocator() override;
 
 private:
  std::vector<std::unique_ptr<experimental::ServerInterceptorFactoryInterface>>*
  interceptor_creators() override {
    return &interceptor_creators_;
  }
 
  friend class AsyncGenericService;
  friend class ServerBuilder;
  friend class ServerInitializer;
 
  class SyncRequest;
  class CallbackRequestBase;
  template <class ServerContextType>
  class CallbackRequest;
  class UnimplementedAsyncRequest;
  class UnimplementedAsyncResponse;
 
  class SyncRequestThreadManager;
 
  void RegisterAsyncGenericService(AsyncGenericService* service) override;
 
  void RegisterCallbackGenericService(CallbackGenericService* service) override;
 
  void RegisterContextAllocator(
      std::unique_ptr<ContextAllocator> context_allocator) {
    context_allocator_ = std::move(context_allocator);
  }
 
  void PerformOpsOnCall(internal::CallOpSetInterface* ops,
                        internal::Call* call) override;
 
  void ShutdownInternal(gpr_timespec deadline)
      ABSL_LOCKS_EXCLUDED(mu_) override;
 
  int max_receive_message_size() const override {
    return max_receive_message_size_;
  }
 
  bool call_metric_recording_enabled() const override {
    return call_metric_recording_enabled_;
  }
 
  experimental::ServerMetricRecorder* server_metric_recorder() const override {
    return server_metric_recorder_;
  }
 
  CompletionQueue* CallbackCQ() ABSL_LOCKS_EXCLUDED(mu_) override;
 
  ServerInitializer* initializer();
 
  // Functions to manage the server shutdown ref count. Things that increase
  // the ref count are the running state of the server (take a ref at start and
  // drop it at shutdown) and each running callback RPC.
  void Ref();
  void UnrefWithPossibleNotify() ABSL_LOCKS_EXCLUDED(mu_);
  void UnrefAndWaitLocked() ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_);
 
  std::vector<std::shared_ptr<internal::ExternalConnectionAcceptorImpl>>
      acceptors_;
 
  // A vector of interceptor factory objects.
  // This should be destroyed after health_check_service_ and this requirement
  // is satisfied by declaring interceptor_creators_ before
  // health_check_service_. (C++ mandates that member objects be destroyed in
  // the reverse order of initialization.)
  std::vector<std::unique_ptr<experimental::ServerInterceptorFactoryInterface>>
      interceptor_creators_;
 
  int max_receive_message_size_;
 
  std::shared_ptr<std::vector<std::unique_ptr<ServerCompletionQueue>>>
      sync_server_cqs_;
 
  std::vector<std::unique_ptr<SyncRequestThreadManager>> sync_req_mgrs_;
 
  // Memory allocator for the server.
  grpc_event_engine::experimental::MemoryAllocator memory_allocator_;
 
  // Server status
  mutable internal::Mutex mu_;
  bool started_;
  bool shutdown_ ABSL_GUARDED_BY(mu_);
  bool shutdown_notified_
      ABSL_GUARDED_BY(mu_);  // Was notify called on the shutdown_cv_
  internal::CondVar shutdown_done_cv_;
  bool shutdown_done_ ABSL_GUARDED_BY(mu_) = false;
  std::atomic_int shutdown_refs_outstanding_{1};
 
  internal::CondVar shutdown_cv_;
 
  std::shared_ptr<GlobalCallbacks> global_callbacks_;
 
  std::vector<std::string> services_;
  bool has_async_generic_service_ = false;
  bool has_callback_generic_service_ = false;
  bool has_callback_methods_ = false;
 
  // Pointer to the wrapped grpc_server.
  grpc_server* server_;
 
  std::unique_ptr<ServerInitializer> server_initializer_;
 
  std::unique_ptr<ContextAllocator> context_allocator_;
 
  std::unique_ptr<HealthCheckServiceInterface> health_check_service_;
  bool health_check_service_disabled_;
 
  // When appropriate, use a default callback generic service to handle
  // unimplemented methods
  std::unique_ptr<CallbackGenericService> unimplemented_service_;
 
  // A special handler for resource exhausted in sync case
  std::unique_ptr<internal::MethodHandler> resource_exhausted_handler_;
 
  // Handler for callback generic service, if any
  std::unique_ptr<internal::MethodHandler> generic_handler_;
 
  // callback_cq_ references the callbackable completion queue associated
  // with this server (if any). It is set on the first call to CallbackCQ().
  // It is _not owned_ by the server; ownership belongs with its internal
  // shutdown callback tag (invoked when the CQ is fully shutdown).
  std::atomic<CompletionQueue*> callback_cq_{nullptr};
 
  // List of CQs passed in by user that must be Shutdown only after Server is
  // Shutdown.  Even though this is only used with NDEBUG, instantiate it in all
  // cases since otherwise the size will be inconsistent.
  std::vector<CompletionQueue*> cq_list_;
 
  // Whetner per-call load reporting is enabled.
  bool call_metric_recording_enabled_ = false;
 
  // Interface to read or update server-wide metrics. Optional.
  experimental::ServerMetricRecorder* server_metric_recorder_ = nullptr;
};
 
}  // namespace grpc
 
#endif  // GRPCPP_SERVER_H