ref-count.hpp
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/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
/*
* Main authors:
* Christian Schulte <schulte@gecode.org>
*
* Copyright:
* Christian Schulte, 2017
*
* This file is part of Gecode, the generic constraint
* development environment:
* http://www.gecode.org
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
*/
#include <atomic>
namespace Gecode { namespace Support {
class RefCount {
protected:
std::atomic_ulong n;
public:
RefCount(unsigned long int n);
void inc(void);
bool dec(void);
operator bool(void) const;
};
forceinline
RefCount::RefCount(unsigned long int n0) {
n.store(n0,std::memory_order_release);
}
forceinline void
RefCount::inc(void) {
(void) n.fetch_add(1U,std::memory_order_relaxed);
}
forceinline bool
RefCount::dec(void) {
return n.fetch_sub(1U,std::memory_order_acq_rel) == 1U;
}
forceinline
RefCount::operator bool(void) const {
return n.load(std::memory_order_acquire) > 0U;
}
}}
// STATISTICS: support-any
Gecode::Support::RefCount::dec
bool dec(void)
Decrement counter and return true if it hits zero.
Definition ref-count.hpp:63
Gecode::Support::RefCount::inc
void inc(void)
Increment counter.
Definition ref-count.hpp:59
Gecode::Support::RefCount::n
std::atomic_ulong n
The reference count.
Definition ref-count.hpp:42
Gecode::Support::RefCount::RefCount
RefCount(unsigned long int n)
Initialize.
Definition ref-count.hpp:55
Gecode::Support
Support algorithms and datastructures
Gecode
Gecode toplevel namespace
forceinline
#define forceinline
Definition config.hpp:187