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base / scoped_clear_last_error.h [blame]
// Copyright 2018 The Chromium Authors
// 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 <errno.h>
#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_