// filename:c2011-7-17-3-ex.c
// original examples and/or notes:
// 		(c) ISO/IEC JTC1 SC22 WG14 N1570, April 12, 2011
// 			C2011 7.17.3 Order and consistency
// compile and output mechanism:
// 		(c) Ogawa Kiyoshi, kaizen@gifu-u.ac.jp, December.29, 2013
// compile errors and/or wornings:
// 		(c) Apple LLVM version 4.2 (clang-425.0.27) (based on LLVM 3.2svn)
// 			Target: x86_64-apple-darwin11.4.2 //Thread model: posix
// 		(c) LLVM 2003-2009 University of Illinois at Urbana-Champaign.
// gcc-4.9 (GCC) 4.9.0 20131229 (experimental)
// Copyright (C) 2013 Free Software Foundation, Inc.
#include <stdio.h>
#include <stdatomic.h>

int main(void)
{
	int r1, r2, x, y;
// Thread 1:
	r1 = atomic_load_explicit(&y, memory_order_relaxed);
		printf("r1=%d ",r1);
	atomic_store_explicit(&x, r1, memory_order_relaxed);
		printf("x=%d ",x);
// Thread 2:
	r2 = atomic_load_explicit(&x, memory_order_relaxed);
		printf("r2=%d ",r2);
	atomic_store_explicit(&y, 42, memory_order_relaxed);
		printf("y=%d ",y);
	
	atomic_store_explicit(&y, 42, memory_order_relaxed);
				printf("y=%d ",y);
	r1 = atomic_load_explicit(&y, memory_order_relaxed);
			printf("r1=%d ",r1);
	atomic_store_explicit(&x, r1, memory_order_relaxed);
				printf("x=%d ",x);
	r2 = atomic_load_explicit(&x, memory_order_relaxed);
			printf("r2=%d ",r2);
	
// Thread 1:
	r1 = atomic_load_explicit(&y, memory_order_relaxed);
			printf("r1=%d ",r1);
	atomic_store_explicit(&x, r1, memory_order_relaxed);
			printf("x=%d ",x);
// Thread 2:
	r2 = atomic_load_explicit(&x, memory_order_relaxed);
			printf("r2=%d ",r2);
	atomic_store_explicit(&y, r2, memory_order_relaxed);
		printf("y=%d ",y);
return printf("\n7.17.3 Order and consistency \n");
}
// gcc output  may be