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ref-count.hpp
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1/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
2/*
3 * Main authors:
4 * Christian Schulte <schulte@gecode.org>
5 *
6 * Copyright:
7 * Christian Schulte, 2017
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33
34#include <atomic>
35
36namespace Gecode { namespace Support {
37
39 class RefCount {
40 protected:
42 std::atomic_ulong n;
43 public:
45 RefCount(unsigned long int n);
47 void inc(void);
49 bool dec(void);
51 operator bool(void) const;
52 };
53
55 RefCount::RefCount(unsigned long int n0) {
56 n.store(n0,std::memory_order_release);
57 }
58 forceinline void
60 (void) n.fetch_add(1U,std::memory_order_relaxed);
61 }
62 forceinline bool
64 return n.fetch_sub(1U,std::memory_order_acq_rel) == 1U;
65 }
67 RefCount::operator bool(void) const {
68 return n.load(std::memory_order_acquire) > 0U;
69 }
70
71}}
72
73// STATISTICS: support-any
int n
Number of negative literals for node type.
A class for thread-safe reference counting.
Definition ref-count.hpp:39
bool dec(void)
Decrement counter and return true if it hits zero.
Definition ref-count.hpp:63
void inc(void)
Increment counter.
Definition ref-count.hpp:59
std::atomic_ulong n
The reference count.
Definition ref-count.hpp:42
RefCount(unsigned long int n)
Initialize.
Definition ref-count.hpp:55
Gecode toplevel namespace
#define forceinline
Definition config.hpp:187