Difference between single directive and sections in OpenMP

Question

I understand, I can use the directive singleto do the same work as when using sectionsjust add nowaitflags

The following code is no different from me compared to the directive section:

    void main(){
    #pragma omp parallel
        {
            int tid = omp_get_thread_num();
    #pragma omp single nowait
            {
                printf("Thread %d in #1 single construct.\n", tid);
            }
    #pragma omp single nowait
            {
                printf("Thread %d in #2 single construct.\n", tid);
            }
    #pragma omp single nowait
            {
                printf("Thread %d in #3 single construct.\n", tid);
            }
        }
    }

Can someone give me some examples using directives sectionsand singlein different scenarios?

Answer 1

, single sections , , .

, single copyprivate, :

... , .

workbaring sections, , lastprivate reduction, single .

, , :

#pragma omp single nowait
        {
            printf("Thread %d in #1 single construct.\n", tid);
        }
#pragma omp single nowait
        {
            printf("Thread %d in #2 single construct.\n", tid);
        }
#pragma omp single nowait
        {
            printf("Thread %d in #3 single construct.\n", tid);
        } // No barrier here

a sections, a sections nowait. a sections, , single .

Answer 2

single nowait , sections. OpenMP , single. , . OpenMP. , , .

, , , single . sections , for, for switch section. , .

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