casacore
OMP.h
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2 //# Associated Universities, Inc. Washington DC, USA.
3 //#
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25 
26 #ifndef CASA_OS_OMP_H
27 #define CASA_OS_OMP_H
28 
29 #include <casacore/casa/aips.h>
30 #ifdef _OPENMP
31 #include <omp.h>
32 #endif
33 
34 namespace casacore {
35  namespace OMP {
36 
37  // Get the maximum number of threads.
38  // OpenMP sets it to the env.var. OMP_NUM_THREADS. If undefined, it is
39  // the number of cores.
40  // If OpenMP is not used, 1 is returned.
41  inline uInt maxThreads()
42  {
43 #ifdef _OPENMP
44  return omp_get_max_threads();
45 #else
46  return 1;
47 #endif
48  }
49  // Backward
51 
52  // Set the number of threads to use. Note it can be overridden
53  // for a parallel section by 'omp parallel num_threads(n)'.
54  // Nothing is done if OpenMP is not used.
55 #ifdef _OPENMP
56  inline void setNumThreads (uInt n)
57  { omp_set_num_threads (n); }
58 #else
59  inline void setNumThreads (uInt)
60  {}
61 #endif
62 
63  // Get the number of threads used in a parallel piece of code.
64  // If OpenMP is not used, 1 is returned.
65  inline uInt numThreads()
66  {
67 #ifdef _OPENMP
68  return omp_get_num_threads();
69 #else
70  return 1;
71 #endif
72  }
73 
74  // Get the thread number (0 till numThreads).
75  // If OpenMP is not used, 0 is returned.
76  inline uInt threadNum()
77  {
78 #ifdef _OPENMP
79  return omp_get_thread_num();
80 #else
81  return 0;
82 #endif
83  }
84 
85  // Set if nested parallel sections are possible or not.
86  // Nothing is done if OpenMP is not used.
87 #ifdef _OPENMP
88  inline void setNested (Bool nest)
89  { omp_set_nested (nest); }
90 #else
91  inline void setNested (Bool)
92  {}
93 #endif
94 
95  // Test if nested parallel sections are possible.
96  // If OpenMP is not used, false is returned.
97  inline bool nested()
98  {
99 #ifdef _OPENMP
100  return omp_get_nested();
101 #else
102  return false;
103 #endif
104  }
105 
106  } // end namespace
107 } // end namespace
108 
109 #endif
bool nested()
Test if nested parallel sections are possible.
Definition: OMP.h:97
uInt numThreads()
Get the number of threads used in a parallel piece of code.
Definition: OMP.h:65
void setNumThreads(uInt)
Set the number of threads to use.
Definition: OMP.h:59
uInt threadNum()
Get the thread number (0 till numThreads).
Definition: OMP.h:76
uInt nMaxThreads()
Backward
void setNested(Bool)
Set if nested parallel sections are possible or not.
Definition: OMP.h:91
uInt maxThreads()
Get the maximum number of threads.
Definition: OMP.h:41
this file contains all the compiler specific defines
Definition: mainpage.dox:28
unsigned int uInt
Definition: aipstype.h:51
bool Bool
Define the standard types used by Casacore.
Definition: aipstype.h:42