/*
*
* 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 <condition_variable>
#include <list>
#include <memory>
#include <mutex>
#include <vector>
#include <grpc/compression.h>
#include <grpcpp/completion_queue.h>
#include <grpcpp/impl/call.h>
#include <grpcpp/impl/codegen/grpc_library.h>
#include <grpcpp/impl/codegen/server_interface.h>
#include <grpcpp/impl/rpc_service_method.h>
#include <grpcpp/security/server_credentials.h>
#include <grpcpp/support/channel_arguments.h>
#include <grpcpp/support/config.h>
#include <grpcpp/support/status.h>
struct grpc_server;
namespace grpc {
class AsyncGenericService;
class HealthCheckServiceInterface;
class ServerContext;
class ServerInitializer;
/// Represents a gRPC server.
///
/// Use a \a grpc::ServerBuilder to create, configure, and start
/// \a Server instances.
class Server : public ServerInterface, private GrpcLibraryCodegen {
public:
~Server();
/// Block until the server shuts down.
///
/// \warning The server must be either shutting down or some other thread must
/// call \a Shutdown for this function to ever return.
void Wait() override;
/// Global callbacks are a set of hooks that are called when server
/// events occur. \a SetGlobalCallbacks method is used to register
/// the hooks with gRPC. Note that
/// the \a GlobalCallbacks instance will be shared among all
/// \a Server instances in an application and can be set exactly
/// once per application.
class GlobalCallbacks {
public:
virtual ~GlobalCallbacks() {}
/// Called before server is created.
virtual void UpdateArguments(ChannelArguments* args) {}
/// Called before application callback for each synchronous server request
virtual void PreSynchronousRequest(ServerContext* context) = 0;
/// Called after application callback for each synchronous server request
virtual void PostSynchronousRequest(ServerContext* context) = 0;
/// Called before server is started.
virtual void PreServerStart(Server* server) {}
/// Called after a server port is added.
virtual void AddPort(Server* server, const grpc::string& addr,
ServerCredentials* creds, int port) {}
};
/// Set the global callback object. Can only be called once per application.
/// Does not take ownership of callbacks, and expects the pointed to object
/// to be alive until all server objects in the process have been destroyed.
/// The same \a GlobalCallbacks object will be used throughout the
/// application and is shared among all \a Server objects.
static void SetGlobalCallbacks(GlobalCallbacks* callbacks);
/// Returns a \em raw pointer to the underlying \a grpc_server instance.
/// EXPERIMENTAL: for internal/test use only
grpc_server* c_server();
/// Returns the health check service.
HealthCheckServiceInterface* GetHealthCheckService() const {
return health_check_service_.get();
}
/// Establish a channel for in-process communication
std::shared_ptr<Channel> InProcessChannel(const ChannelArguments& args);
protected:
/// Register a service. This call does not take ownership of the service.
/// The service must exist for the lifetime of the Server instance.
bool RegisterService(const grpc::string* host, Service* service) override;
/// Try binding the server to the given \a addr endpoint
/// (port, and optionally including IP address to bind to).
///
/// It can be invoked multiple times. Should be used before
/// starting the server.
///
/// \param addr The address to try to bind to the server (eg, localhost:1234,
/// 192.168.1.1:31416, [::1]:27182, etc.).
/// \param creds The credentials associated with the server.
///
/// \return bound port number on success, 0 on failure.
///
/// \warning It is an error to call this method on an already started server.
int AddListeningPort(const grpc::string& addr,
ServerCredentials* creds) override;
/// NOTE: This is *NOT* a public API. The server constructors are supposed to
/// be used by \a ServerBuilder class only. The constructor will be made
/// 'private' very soon.
///
/// Server constructors. To be used by \a ServerBuilder only.
///
/// \param max_message_size Maximum message length that the channel can
/// receive.
///
/// \param args The channel args
///
/// \param sync_server_cqs The completion queues to use if the server is a
/// synchronous server (or a hybrid server). The server polls for new RPCs on
/// these queues
///
/// \param min_pollers The minimum number of polling threads per server
/// completion queue (in param sync_server_cqs) to use for listening to
/// incoming requests (used only in case of sync server)
///
/// \param max_pollers The maximum number of polling threads per server
/// completion queue (in param sync_server_cqs) to use for listening to
/// incoming requests (used only in case of sync server)
///
/// \param sync_cq_timeout_msec The timeout to use when calling AsyncNext() on
/// server completion queues passed via sync_server_cqs param.
Server(int max_message_size, 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,
grpc_resource_quota* server_rq = nullptr);
/// Start the server.
///
/// \param cqs Completion queues for handling asynchronous services. The
/// caller is required to keep all completion queues live until the server is
/// destroyed.
/// \param num_cqs How many completion queues does \a cqs hold.
void Start(ServerCompletionQueue** cqs, size_t num_cqs) override;
grpc_server* server() override { return server_; };
private:
friend class AsyncGenericService;
friend class ServerBuilder;
friend class ServerInitializer;
class SyncRequest;
class UnimplementedAsyncRequest;
class UnimplementedAsyncResponse;
/// SyncRequestThreadManager is an implementation of ThreadManager. This class
/// is responsible for polling for incoming RPCs and calling the RPC handlers.
/// This is only used in case of a Sync server (i.e a server exposing a sync
/// interface)
class SyncRequestThreadManager;
/// Register a generic service. This call does not take ownership of the
/// service. The service must exist for the lifetime of the Server instance.
void RegisterAsyncGenericService(AsyncGenericService* service) override;
void PerformOpsOnCall(internal::CallOpSetInterface* ops,
internal::Call* call) override;
void ShutdownInternal(gpr_timespec deadline) override;
int max_receive_message_size() const override {
return max_receive_message_size_;
};
ServerInitializer* initializer();
const int max_receive_message_size_;
/// The following completion queues are ONLY used in case of Sync API
/// i.e. if the server has any services with sync methods. The server uses
/// these completion queues to poll for new RPCs
std::shared_ptr<std::vector<std::unique_ptr<ServerCompletionQueue>>>
sync_server_cqs_;
/// List of \a ThreadManager instances (one for each cq in
/// the \a sync_server_cqs)
std::vector<std::unique_ptr<SyncRequestThreadManager>> sync_req_mgrs_;
// Server status
std::mutex mu_;
bool started_;
bool shutdown_;
bool shutdown_notified_; // Was notify called on the shutdown_cv_
std::condition_variable shutdown_cv_;
std::shared_ptr<GlobalCallbacks> global_callbacks_;
std::vector<grpc::string> services_;
bool has_generic_service_;
// Pointer to the wrapped grpc_server.
grpc_server* server_;
std::unique_ptr<ServerInitializer> server_initializer_;
std::unique_ptr<HealthCheckServiceInterface> health_check_service_;
bool health_check_service_disabled_;
// A special handler for resource exhausted in sync case
std::unique_ptr<internal::MethodHandler> resource_exhausted_handler_;
};
} // namespace grpc
#endif // GRPCPP_SERVER_H