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ref-count.hpp
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37 
38 #include <atomic>
39 
40 namespace Gecode { namespace Support {
41 
43  class RefCount {
44  protected:
46  std::atomic_ulong n;
47  public:
49  RefCount(unsigned long int n);
51  void inc(void);
53  bool dec(void);
55  operator bool(void) const;
56  };
57 
59  RefCount::RefCount(unsigned long int n0) {
60  n.store(n0,std::memory_order_release);
61  }
62  forceinline void
63  RefCount::inc(void) {
64  (void) n.fetch_add(1U,std::memory_order_relaxed);
65  }
66  forceinline bool
67  RefCount::dec(void) {
68  return n.fetch_sub(1U,std::memory_order_acq_rel) == 1U;
69  }
71  RefCount::operator bool(void) const {
72  return n.load(std::memory_order_acquire) > 0U;
73  }
74 
75 }}
76 
77 // STATISTICS: support-any
#define forceinline
Definition: config.hpp:182
bool dec(void)
Decrement counter and return true if it hits zero.
Definition: ref-count.hpp:67
std::atomic_ulong n
The reference count.
Definition: ref-count.hpp:46
void inc(void)
Increment counter.
Definition: ref-count.hpp:63
RefCount(unsigned long int n)
Initialize.
Definition: ref-count.hpp:59
A class for thread-safe reference counting.
Definition: ref-count.hpp:43
Gecode toplevel namespace