ref: 8a55687988cf79a053d10992a60c7d0ddaafdd6c
dir: /sys/src/ape/lib/ap/68020/lock.c/
#define _LOCK_EXTENSION
#include "../plan9/sys9.h"
#include <lock.h>
int	tas(int*);
void
lock(Lock *lk)
{
	while(tas(&lk->val))
		_SLEEP(0);
}
int
canlock(Lock *lk)
{
	if(tas(&lk->val))
		return 0;
	return 1;
}
void
unlock(Lock *lk)
{
	lk->val = 0;
}