shithub: plan9front

ref: 30bf1c45cac396a3b9637cfe40cb1bba4ebca7a9
dir: /sys/src/ape/lib/ap/amd64/lock.c/

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#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;
}