// Copyright 2018 The Chromium Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #ifndef BASE_SCOPED_CLEAR_LAST_ERROR_H_ #define BASE_SCOPED_CLEAR_LAST_ERROR_H_ #include #include "base/base_export.h" #include "build/build_config.h" namespace base { // ScopedClearLastError stores and resets the value of thread local error codes // (errno, GetLastError()), and restores them in the destructor. This is useful // to avoid side effects on these values in instrumentation functions that // interact with the OS. // Common implementation of ScopedClearLastError for all platforms. Use // ScopedClearLastError instead. class BASE_EXPORT ScopedClearLastErrorBase { public: ScopedClearLastErrorBase() : last_errno_(errno) { errno = 0; } ScopedClearLastErrorBase(const ScopedClearLastErrorBase&) = delete; ScopedClearLastErrorBase& operator=(const ScopedClearLastErrorBase&) = delete; ~ScopedClearLastErrorBase() { errno = last_errno_; } private: const int last_errno_; }; #if BUILDFLAG(IS_WIN) // Windows specific implementation of ScopedClearLastError. class BASE_EXPORT ScopedClearLastError : public ScopedClearLastErrorBase { public: ScopedClearLastError(); ScopedClearLastError(const ScopedClearLastError&) = delete; ScopedClearLastError& operator=(const ScopedClearLastError&) = delete; ~ScopedClearLastError(); private: const unsigned long last_system_error_; }; #elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA) using ScopedClearLastError = ScopedClearLastErrorBase; #endif // BUILDFLAG(IS_WIN) } // namespace base #endif // BASE_SCOPED_CLEAR_LAST_ERROR_H_