| // Licensed to the Apache Software Foundation (ASF) under one |
| // or more contributor license agreements. See the NOTICE file |
| // distributed with this work for additional information |
| // regarding copyright ownership. The ASF licenses this file |
| // to you 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. |
| #pragma once |
| |
| #include <cstdint> |
| #include <string> |
| #include <vector> |
| |
| #include "kudu/clock/time_service.h" |
| #include "kudu/gutil/macros.h" |
| #include "kudu/util/status.h" |
| |
| namespace kudu { |
| namespace clock { |
| |
| // TimeService implementation which uses the 'ntp_adjtime' call (corresponding to the |
| // 'adjtimex' syscall) to consult the Linux kernel for the current time |
| // and error bound. |
| // |
| // This implementation relies on the ntpd service running on the local host |
| // to keep the kernel's timekeeping up to date and in sync. |
| class SystemNtp : public TimeService { |
| public: |
| SystemNtp(); |
| |
| Status Init() override; |
| |
| Status WalltimeWithError(uint64_t* now_usec, uint64_t* error_usec) override; |
| |
| int64_t skew_ppm() const override { |
| return skew_ppm_; |
| } |
| |
| void DumpDiagnostics(std::vector<std::string>* log) const override; |
| |
| private: |
| // The maximum possible clock frequency skew rate reported by the kernel, |
| // parts-per-million (PPM). |
| int64_t skew_ppm_; |
| |
| DISALLOW_COPY_AND_ASSIGN(SystemNtp); |
| }; |
| |
| } // namespace clock |
| } // namespace kudu |