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Semaphore.h
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1 //
2 // Copyright (c) 2009, Markus Rickert
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29 
30 #ifndef _RL_UTIL_SEMAPHORE_H_
31 #define _RL_UTIL_SEMAPHORE_H_
32 
33 #ifdef WIN32
34 #include <windows.h>
35 #else // WIN32
36 #include <semaphore.h>
37 #endif // WIN32
38 
39 namespace rl
40 {
41  namespace util
42  {
43  class Semaphore
44  {
45  public:
46  explicit Semaphore(const ::std::size_t& n) :
47 #ifdef WIN32
48  semaphore(CreateSemaphore(NULL, n, n, NULL))
49 #else // WIN32
50  semaphore()
51 #endif // WIN32
52  {
53 #ifndef WIN32
54  sem_init(&(*this).semaphore, 0, n);
55 #endif // WIN32
56  }
57 
58  virtual ~Semaphore()
59  {
60 #ifdef WIN32
61  CloseHandle((*this).semaphore);
62 #else // WIN32
63  sem_destroy(&(*this).semaphore);
64 #endif // WIN32
65  }
66 
68  {
69  (*this).release();
70  return (*this);
71  }
72 
74  {
75  (*this).acquire();
76  return (*this);
77  }
78 
79  void acquire()
80  {
81 #ifdef WIN32
82  WaitForSingleObject((*this).semaphore, INFINITE);
83 #else // WIN32
84  sem_wait(&(*this).semaphore);
85 #endif // WIN32
86  }
87 
88  void release()
89  {
90 #ifdef WIN32
91  ReleaseSemaphore((*this).semaphore, 1, NULL);
92 #else // WIN32
93  sem_post(&(*this).semaphore);
94 #endif // WIN32
95  }
96 
97  bool tryAcquire()
98  {
99 #ifdef WIN32
100  return WaitForSingleObject((*this).semaphore, 0) == WAIT_OBJECT_0 ? false : true;
101 #else // WIN32
102  return sem_trywait(&(*this).semaphore) == 0 ? true : false;
103 #endif // WIN32
104  }
105 
106  protected:
107 
108  private:
109 #ifdef WIN32
110  HANDLE semaphore;
111 #else // WIN32
112  sem_t semaphore;
113 #endif // WIN32
114  };
115  }
116 }
117 
118 #endif // _RL_UTIL_SEMAPHORE_H_