gcc/libgomp/testsuite/libgomp.c/cancel-parallel-2.c

/* { dg-do run } */
/* { dg-set-target-env-var OMP_CANCELLATION "true" } */

#include <stdlib.h>
#include <unistd.h>
#include <omp.h>

static void
foo (int *x)
{
  #pragma omp parallel firstprivate(x) num_threads (32)
  {
    int thr = omp_get_thread_num ();
    switch (x[thr])
      {
      case 4:;
	#pragma omp cancel parallel
	break;
      case 3:
	#pragma omp task
	usleep (1000);
	#pragma omp task
	usleep (2000);
	#pragma omp task
	usleep (4000);
	break;
      case 2:
	usleep (1000);
	/* FALLTHRU */
      case 1:;
	#pragma omp cancellation point parallel
	break;
      }
    #pragma omp barrier
    if (omp_get_cancellation ())
      abort ();
  }
}

int
main ()
{
  int i, j, x[32] = { 0, 1, 2, 4, 2, 2, 1, 0 };
  foo (x);
  for (i = 0; i < 32; i++)
    {
      for (j = 0; j < 32; j++)
	x[j] = rand () & 3;
      x[rand () & 31] = 4;
      foo (x);
    }
  return 0;
}