#include <stdio.h>

struct {
	unsigned char flag;
	unsigned char val;
} l;

int main(int argc, char **argv)
{
	int i;

#   pragma omp sections 
	{
#       pragma omp section
		{
			for (i = 0; i < 100000000; i++) {
				l.val += 2;
				asm volatile("lock or $0x0,(%%rsp)" : : : "memory");
				if (l.flag)
					break;
				asm volatile("" : : : "memory");
			}
			l.flag = 1;
		}
#       pragma omp section
		while(!l.flag)
			asm volatile("":::"memory");
			//asm volatile("lock orb $0x0, %0"::"m"(l.flag):"memory");
	}
	return 0;
}