diff options
Diffstat (limited to 'bits')
| -rw-r--r-- | bits/atomic_wide_counter.h | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/bits/atomic_wide_counter.h b/bits/atomic_wide_counter.h new file mode 100644 index 0000000000..0687eb554e --- /dev/null +++ b/bits/atomic_wide_counter.h @@ -0,0 +1,35 @@ +/* Monotonically increasing wide counters (at least 62 bits). + Copyright (C) 2016-2021 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#ifndef _BITS_ATOMIC_WIDE_COUNTER_H +#define _BITS_ATOMIC_WIDE_COUNTER_H + +/* Counter that is monotonically increasing (by less than 2**31 per + increment), with a single writer, and an arbitrary number of + readers. */ +typedef union +{ + __extension__ unsigned long long int __value64; + struct + { + unsigned int __low; + unsigned int __high; + } __value32; +} __atomic_wide_counter; + +#endif /* _BITS_ATOMIC_WIDE_COUNTER_H */ |