git: 9front

ref: e8f5e0909f4a7c7ae2c4e85f563e6b4da88aa98f
dir: /sys/src/ape/lib/ap/386/lock.c/

View raw version 
#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;
}