1 // Copyright 2020 The Pigweed Authors 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); you may not 4 // use this file except in compliance with the License. You may obtain a copy of 5 // the License at 6 // 7 // https://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 11 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 12 // License for the specific language governing permissions and limitations under 13 // the License. 14 #pragma once 15 16 // Ideally we'd use std::chrono::steady_clock::period, however this is not 17 // something we can expose to the C API. Instead we assume it has nanosecond 18 // compatibility and we rely on implicit conversion to tell us at compile time 19 // whether this is incompatible. 20 #define PW_CHRONO_SYSTEM_CLOCK_PERIOD_SECONDS_NUMERATOR 1 21 #define PW_CHRONO_SYSTEM_CLOCK_PERIOD_SECONDS_DENOMINATOR 100'000'0000 22 23 #ifdef __cplusplus 24 25 #include "pw_chrono/epoch.h" 26 27 namespace pw::chrono::backend { 28 29 // The std::chrono::steady_clock does not have a defined epoch. 30 constexpr inline Epoch kSystemClockEpoch = pw::chrono::Epoch::kUnknown; 31 32 // The std::chrono::steady_clock can be used by signal handlers. 33 constexpr inline bool kSystemClockNmiSafe = true; 34 35 // The std::chrono::steady_clock ticks while in a signal handler. 36 constexpr inline bool kSystemClockFreeRunning = true; 37 38 } // namespace pw::chrono::backend 39 40 #endif // __cplusplus 41