1 // Copyright 2022 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 #include <mutex> 17 18 namespace pw::sync::backend { 19 20 // The NativeRecursiveMutex class adds a flag that tracks how many times the 21 // std::recursive_mutex has been locked. The C++ standard states that misusing a 22 // mutex is undefined behavior, so library implementations may simply ignore 23 // misuse. This ensures misuse hits a PW_ASSERT. 24 struct NativeRecursiveMutex { 25 std::recursive_mutex mutex; 26 unsigned lock_count = 0; 27 }; 28 29 using NativeRecursiveMutexHandle = std::recursive_mutex&; 30 31 } // namespace pw::sync::backend 32