1 // g2o - General Graph Optimization
2 // Copyright (C) 2011 R. Kuemmerle, G. Grisetti, W. Burgard
3 // All rights reserved.
4 //
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26 
27 #ifndef G2O_OPENMP_MUTEX
28 #define G2O_OPENMP_MUTEX
29 
30 #include "g2o/config.h"
31 
32 #ifdef G2O_OPENMP
33 #include <omp.h>
34 #else
35 #include <cassert>
36 #endif
37 
38 namespace g2o {
39 
40 #ifdef G2O_OPENMP
41 
42   /**
43    * \brief Mutex realized via OpenMP
44    */
45   class OpenMPMutex
46   {
47     public:
OpenMPMutex()48       OpenMPMutex() { omp_init_lock(&_lock); }
~OpenMPMutex()49       ~OpenMPMutex() { omp_destroy_lock(&_lock); }
lock()50       void lock() { omp_set_lock(&_lock); }
unlock()51       void unlock() { omp_unset_lock(&_lock); }
52     protected:
53       omp_lock_t _lock;
54   };
55 
56 #else
57 
58   /*
59    * dummy which does nothing in case we don't have OpenMP support.
60    * In debug mode, the mutex allows to verify the correct lock and unlock behavior
61    */
62   class OpenMPMutex
63   {
64     public:
65 #ifdef NDEBUG
66       OpenMPMutex() {}
67 #else
68       OpenMPMutex() : _cnt(0) {}
69 #endif
70       ~OpenMPMutex() { assert(_cnt == 0 && "Freeing locked mutex");}
71       void lock() { assert(++_cnt == 1 && "Locking already locked mutex");}
72       void unlock() { assert(--_cnt == 0 && "Trying to unlock a mutex which is not locked");}
73     protected:
74 #ifndef NDEBUG
75       char _cnt;
76 #endif
77   };
78 
79 #endif
80 
81   /**
82    * \brief lock a mutex within a scope
83    */
84   class ScopedOpenMPMutex
85   {
86     public:
ScopedOpenMPMutex(OpenMPMutex * mutex)87       explicit ScopedOpenMPMutex(OpenMPMutex* mutex) : _mutex(mutex) { _mutex->lock(); }
~ScopedOpenMPMutex()88       ~ScopedOpenMPMutex() { _mutex->unlock(); }
89     private:
90       OpenMPMutex* const _mutex;
91       ScopedOpenMPMutex(const ScopedOpenMPMutex&);
92       void operator=(const ScopedOpenMPMutex&);
93   };
94 
95 }
96 
97 #endif
98