#include "../threadimpl.h"#undef exits  ucontext_t c0, c1;char stack[65536]; voidgo(void *v){	print("hello, world\n");	setcontext(&c0);} voidmain(void){//	print("in main\n");	getcontext(&c1);	c1.uc_stack.ss_sp = stack;	c1.uc_stack.ss_size = sizeof stack;	makecontext(&c1, go, 1, 0);	if(getcontext(&c0) == 0)		setcontext(&c1);	print("back in main\n");	exits(0);}