1 /* 2 * Copyright (C) 2020 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 INCLUDE_PERFETTO_BASE_PLATFORM_HANDLE_H_ 18 #define INCLUDE_PERFETTO_BASE_PLATFORM_HANDLE_H_ 19 20 #include "perfetto/base/build_config.h" 21 22 namespace perfetto { 23 namespace base { 24 25 // PlatformHandle should be used only for types that are HANDLE(s) in Windows. 26 // It should NOT be used to blanket-replace "int fd" in the codebase. 27 // Windows has two types of "handles", which, in UNIX-land, both map to int: 28 // 1. File handles returned by the posix-compatibility API like _open(). 29 // These are just int(s) and should stay such, because all the posix-like API 30 // in Windows.h take an int, not a HANDLE. 31 // 2. Handles returned by old-school WINAPI like CreateFile, CreateEvent etc. 32 // These are proper HANDLE(s). PlatformHandle should be used here. 33 #if PERFETTO_BUILDFLAG(PERFETTO_OS_WIN) 34 // Windows.h typedefs HANDLE to void*. We use void* here to avoid leaking 35 // Windows.h through our headers. 36 using PlatformHandle = void*; 37 38 // On Windows both nullptr and 0xffff... (INVALID_HANDLE_VALUE) are invalid. 39 struct PlatformHandleChecker { IsValidPlatformHandleChecker40 static inline bool IsValid(PlatformHandle h) { 41 return h && h != reinterpret_cast<PlatformHandle>(-1); 42 } 43 }; 44 #else 45 using PlatformHandle = int; 46 struct PlatformHandleChecker { 47 static inline bool IsValid(PlatformHandle h) { return h >= 0; } 48 }; 49 #endif 50 51 // The definition of this lives in base/file_utils.cc (to avoid creating an 52 // extra build edge for a one liner). This is really an alias for close() (UNIX) 53 // CloseHandle() (Windows). THe indirection layer is just to avoid leaking 54 // system headers like Windows.h through perfetto headers. 55 // Thre return value is always UNIX-style: 0 on success, -1 on failure. 56 int ClosePlatformHandle(PlatformHandle); 57 58 } // namespace base 59 } // namespace perfetto 60 61 #endif // INCLUDE_PERFETTO_BASE_PLATFORM_HANDLE_H_ 62