#define _GNU_SOURCE
#include <pthread.h>
#include <stdio.h>

static void print_stacksize(char *label, pthread_attr_t *a)
{
	size_t s;
	pthread_attr_getstacksize(a, &s);
	printf("%s: %zu\n", label, s);
}

int main()
{
	pthread_attr_t a, def;

	pthread_attr_init(&a);
	print_stacksize("original stack size", &a);

	pthread_attr_init(&def);
	pthread_attr_setstacksize(&def, 1234567890);
	pthread_setattr_default_np(&def);

	print_stacksize("stack size after changing default", &a);
	return 0;
}