bits/atomic_wide_counter.h

   1 /* Monotonically increasing wide counters (at least 62 bits).
   2    Copyright (C) 2016-2024 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _BITS_ATOMIC_WIDE_COUNTER_H
  20 #define _BITS_ATOMIC_WIDE_COUNTER_H
  21
  22 /* Counter that is monotonically increasing (by less than 2**31 per
  23    increment), with a single writer, and an arbitrary number of
  24    readers.  */
  25 typedef union
  26 {
  27   __extension__ unsigned long long int __value64;
  28   struct
  29   {
  30     unsigned int __low;
  31     unsigned int __high;
  32   } __value32;
  33 } __atomic_wide_counter;
  34
  35 #endif /* _BITS_ATOMIC_WIDE_COUNTER_H */