/*
* @@name:	masked.1
* @@type:	C
* @@operation:	compile
* @@expect:	success
* @@version:	omp_5.1
*/
#include <stdio.h>

extern float average(float,float,float);

void masked_example( float* x, float* xold, int n, float tol )
{
  int c, i, toobig;
  float error, y;
  c = 0;
  #pragma omp parallel
  {
    do {
      #pragma omp for private(i)
      for( i = 1; i < n-1; ++i ){
        xold[i] = x[i];
      }
      #pragma omp single
      {
        toobig = 0;
      }
      #pragma omp for private(i,y,error) reduction(+:toobig)
      for( i = 1; i < n-1; ++i ){
        y = x[i];
        x[i] = average( xold[i-1], x[i], xold[i+1] );
        error = y - x[i];
        if( error > tol || error < -tol ) ++toobig;
      }
      #pragma omp masked          // primary thread (thread 0)
      {
        ++c;
        printf( "iteration %d, toobig=%d\n", c, toobig );
      }
    } while( toobig > 0 );
    #pragma omp barrier
    #pragma omp masked filter(1)  // thread 1
    {
      // The printf statement will not be executed
      // if the number of threads is less than 2.
      printf( "total number of iterations = %d\n", c );
    }
  }
}