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ref-count.hpp
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33 
34 #include <atomic>
35 
36 namespace 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
59  RefCount::inc(void) {
60  (void) n.fetch_add(1U,std::memory_order_relaxed);
61  }
62  forceinline bool
63  RefCount::dec(void) {
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.
Definition: bool-expr.cpp:234
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
#define forceinline
Definition: config.hpp:192