master

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Specifies that only the master threadshould execute a section of the program.

#pragma omp master  
{  
   code_block  
}  

The master directive supports no OpenMP clauses.

The single directive lets you specify that a section of code should be executed on a single thread, not necessarily the master thread.

For more information, see 2.6.1 master Construct.

// omp_master.cpp  
// compile with: /openmp   
#include <omp.h>  
#include <stdio.h>  
  
int main( )   
{  
    int a[5], i;  
  
    #pragma omp parallel  
    {  
        // Perform some computation.  
        #pragma omp for  
        for (i = 0; i < 5; i++)  
            a[i] = i * i;  
  
        // Print intermediate results.  
        #pragma omp master  
            for (i = 0; i < 5; i++)  
                printf_s("a[%d] = %d\n", i, a[i]);  
  
        // Wait.  
        #pragma omp barrier  
  
        // Continue with the computation.  
        #pragma omp for  
        for (i = 0; i < 5; i++)  
            a[i] += i;  
    }  
}  

a[0] = 0  
a[1] = 1  
a[2] = 4  
a[3] = 9  
a[4] = 16  

Directives