1 // 2 // Copyright 2015 gRPC authors. 3 // 4 // Licensed under the Apache License, Version 2.0 (the "License"); 5 // you may not use this file except in compliance with the License. 6 // You may obtain a copy of the License at 7 // 8 // http://www.apache.org/licenses/LICENSE-2.0 9 // 10 // Unless required by applicable law or agreed to in writing, software 11 // distributed under the License is distributed on an "AS IS" BASIS, 12 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 // See the License for the specific language governing permissions and 14 // limitations under the License. 15 // 16 17 #ifndef GRPC_SRC_CORE_LIB_IOMGR_RESOLVE_ADDRESS_IMPL_H 18 #define GRPC_SRC_CORE_LIB_IOMGR_RESOLVE_ADDRESS_IMPL_H 19 20 #include <grpc/support/port_platform.h> 21 #include <stddef.h> 22 23 #include "src/core/lib/iomgr/exec_ctx.h" 24 #include "src/core/lib/iomgr/port.h" 25 #include "src/core/lib/iomgr/resolve_address.h" 26 27 namespace grpc_core { 28 29 // A fire and forget class to schedule DNS resolution callbacks on the ExecCtx, 30 // which is frequently necessary to avoid lock inversion related problems. 31 class DNSCallbackExecCtxScheduler { 32 public: DNSCallbackExecCtxScheduler(std::function<void (absl::StatusOr<std::vector<grpc_resolved_address>>)> on_done,absl::StatusOr<std::vector<grpc_resolved_address>> param)33 DNSCallbackExecCtxScheduler( 34 std::function<void(absl::StatusOr<std::vector<grpc_resolved_address>>)> 35 on_done, 36 absl::StatusOr<std::vector<grpc_resolved_address>> param) 37 : on_done_(std::move(on_done)), param_(std::move(param)) { 38 GRPC_CLOSURE_INIT(&closure_, RunCallback, this, grpc_schedule_on_exec_ctx); 39 ExecCtx::Run(DEBUG_LOCATION, &closure_, absl::OkStatus()); 40 } 41 42 private: RunCallback(void * arg,grpc_error_handle)43 static void RunCallback(void* arg, grpc_error_handle /* error */) { 44 DNSCallbackExecCtxScheduler* self = 45 static_cast<DNSCallbackExecCtxScheduler*>(arg); 46 self->on_done_(std::move(self->param_)); 47 delete self; 48 } 49 50 const std::function<void(absl::StatusOr<std::vector<grpc_resolved_address>>)> 51 on_done_; 52 absl::StatusOr<std::vector<grpc_resolved_address>> param_; 53 grpc_closure closure_; 54 }; 55 56 } // namespace grpc_core 57 58 #endif // GRPC_SRC_CORE_LIB_IOMGR_RESOLVE_ADDRESS_IMPL_H 59