1 #include "thread/OpenMp.h"
2 #include "math/MathBasic.h"
3 #include "objects/wrappers/Optional.h"
4 #include "thread/CheckFunction.h"
5
6 #ifdef SPH_USE_OPENMP
7 #include <omp.h>
8 #endif
9
10 NAMESPACE_SPH_BEGIN
11
12 #ifdef SPH_USE_OPENMP
13
14 SharedPtr<OmpScheduler> OmpScheduler::globalInstance;
15
OmpScheduler(const Size numThreads)16 OmpScheduler::OmpScheduler(const Size numThreads) {
17 if (numThreads > 0) {
18 omp_set_num_threads(numThreads);
19 }
20 }
21
22 class OmpTaskHandle : public ITask {
23 public:
wait()24 virtual void wait() override {}
25
completed() const26 virtual bool completed() const override {
27 return true;
28 }
29 };
30
31
submit(const Function<void ()> & task)32 SharedPtr<ITask> OmpScheduler::submit(const Function<void()>& task) {
33 if (isMainThread()) {
34 #pragma omp parallel
35 {
36 #pragma omp single
37 {
38 #pragma omp taskgroup
39 {
40 #pragma omp task
41 { task(); }
42 }
43 }
44 }
45 } else {
46 #pragma omp task
47 { task(); }
48 }
49 return makeShared<OmpTaskHandle>();
50 }
51
getThreadIdx() const52 Optional<Size> OmpScheduler::getThreadIdx() const {
53 return omp_get_thread_num();
54 }
55
getThreadCnt() const56 Size OmpScheduler::getThreadCnt() const {
57 return omp_get_max_threads();
58 }
59
getRecommendedGranularity() const60 Size OmpScheduler::getRecommendedGranularity() const {
61 return granularity;
62 }
63
parallelFor(const Size from,const Size to,const Size granularity,const RangeFunctor & functor)64 void OmpScheduler::parallelFor(const Size from,
65 const Size to,
66 const Size granularity,
67 const RangeFunctor& functor) {
68 #pragma omp parallel for schedule(dynamic, 1)
69 for (Size n = from; n < to; n += granularity) {
70 const Size n1 = n;
71 const Size n2 = min(n1 + granularity, to);
72 functor(n1, n2);
73 }
74 }
75
invoke(const OmpScheduler::Functor & task1,const OmpScheduler::Functor & task2)76 static void invoke(const OmpScheduler::Functor& task1, const OmpScheduler::Functor& task2) {
77 #pragma omp taskgroup
78 {
79 #pragma omp task shared(task1)
80 task1();
81
82 #pragma omp task shared(task2)
83 task2();
84 }
85 }
86
parallelInvoke(const Functor & task1,const Functor & task2)87 void OmpScheduler::parallelInvoke(const Functor& task1, const Functor& task2) {
88 if (omp_get_level() == 0) {
89 // top-level call
90 #pragma omp parallel shared(task1, task2)
91 {
92 #pragma omp single
93 { invoke(task1, task2); }
94 }
95 } else {
96 // nested call
97 invoke(task1, task2);
98 }
99 }
100
getGlobalInstance()101 SharedPtr<OmpScheduler> OmpScheduler::getGlobalInstance() {
102 if (!globalInstance) {
103 globalInstance = makeShared<OmpScheduler>();
104 }
105 return globalInstance;
106 }
107
108 #endif
109
110 NAMESPACE_SPH_END
111