base/scoped_clear_errno.h

   1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef BASE_SCOPED_CLEAR_ERRNO_H_
   6 #define BASE_SCOPED_CLEAR_ERRNO_H_
   7
   8 #include <errno.h>
   9
  10 #include "base/basictypes.h"
  11
  12 namespace base {
  13
  14 // Simple scoper that saves the current value of errno, resets it to 0, and on
  15 // destruction puts the old value back.
  16 class ScopedClearErrno {
  17  public:
  18   ScopedClearErrno() : old_errno_(errno) {
  19     errno = 0;
  20   }
  21   ~ScopedClearErrno() {
  22     if (errno == 0)
  23       errno = old_errno_;
  24   }
  25
  26  private:
  27   const int old_errno_;
  28
  29   DISALLOW_COPY_AND_ASSIGN(ScopedClearErrno);
  30 };
  31
  32 }  // namespace base
  33
  34 #endif  // BASE_SCOPED_CLEAR_ERRNO_H_