1 // 2 // Copyright (C) 2022 The Android Open Source Project 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 __IO_URING_CQE_CPP_H 18 #define __IO_URING_CQE_CPP_H 19 20 #include <stdint.h> 21 22 #include <type_traits> 23 24 namespace io_uring_cpp { 25 26 struct IoUringCQE { 27 int32_t res; 28 uint32_t flags; 29 template <typename T> GetDataIoUringCQE30 T GetData() const { 31 static_assert( 32 std::is_trivially_copy_constructible_v<T>, 33 "Only trivially copiable types can be passed for io_uring data"); 34 static_assert(sizeof(T) <= 8, 35 "io_uring SQE's data field has size of 8 bytes, can't pass " 36 "data larger than that."); 37 return *reinterpret_cast<const T*>(&userdata); 38 } 39 IoUringCQEIoUringCQE40 constexpr IoUringCQE(int32_t res, uint32_t flags, uint64_t userdata) 41 : res(res), flags(flags), userdata(userdata) {} 42 43 private: 44 uint64_t userdata; 45 }; 46 47 } // namespace io_uring_cpp 48 49 #endif 50