/* * * Copyright 2016 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 GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_DNS_C_ARES_GRPC_ARES_EV_DRIVER_H #define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_DNS_C_ARES_GRPC_ARES_EV_DRIVER_H #include <grpc/support/port_platform.h> #include <ares.h> #include "src/core/lib/iomgr/pollset_set.h" #include "src/core/lib/iomgr/work_serializer.h" namespace grpc_core { /* A wrapped fd that integrates with the grpc iomgr of the current platform. * A GrpcPolledFd knows how to create grpc platform-specific iomgr endpoints * from "ares_socket_t" sockets, and then sign up for readability/writeability * with that poller, and do shutdown and destruction. */ class GrpcPolledFd { public: virtual ~GrpcPolledFd() {} /* Called when c-ares library is interested and there's no pending callback */ virtual void RegisterForOnReadableLocked(grpc_closure* read_closure) = 0; /* Called when c-ares library is interested and there's no pending callback */ virtual void RegisterForOnWriteableLocked(grpc_closure* write_closure) = 0; /* Indicates if there is data left even after just being read from */ virtual bool IsFdStillReadableLocked() = 0; /* Called once and only once. Must cause cancellation of any pending * read/write callbacks. */ virtual void ShutdownLocked(grpc_error_handle error) = 0; /* Get the underlying ares_socket_t that this was created from */ virtual ares_socket_t GetWrappedAresSocketLocked() = 0; /* A unique name, for logging */ virtual const char* GetName() = 0; }; /* A GrpcPolledFdFactory is 1-to-1 with and owned by the * ares event driver. It knows how to create GrpcPolledFd's * for the current platform, and the ares driver uses it for all of * its fd's. */ class GrpcPolledFdFactory { public: virtual ~GrpcPolledFdFactory() {} /* Creates a new wrapped fd for the current platform */ virtual GrpcPolledFd* NewGrpcPolledFdLocked( ares_socket_t as, grpc_pollset_set* driver_pollset_set, std::shared_ptr<grpc_core::WorkSerializer> work_serializer) = 0; /* Optionally configures the ares channel after creation */ virtual void ConfigureAresChannelLocked(ares_channel channel) = 0; }; std::unique_ptr<GrpcPolledFdFactory> NewGrpcPolledFdFactory( std::shared_ptr<grpc_core::WorkSerializer> work_serializer); } // namespace grpc_core #endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RESOLVER_DNS_C_ARES_GRPC_ARES_EV_DRIVER_H \ */