#include "sys.h"
#include "inode.h"
#include "proc.h"
#include "file.h"

extern long seconds;

       /*
	* Stat system call
	*/
stat(name, buf)
	char *name, *buf;
	{
	fast struct inode *ip;

	if ((ip = iname(name)) != NULL)
		istat(ip, buf);
	}

       /*
	* Fstat system call
	*/
fstat(fd, buf)
	int  fd;
	char *buf;
	{
	fast struct file *fp;

	if ((fp = ofile(fd)) == NULL)
		return;
	ilock(fp->inode);
	istat(fp->inode, buf);
	}

       /*
	* Common code for stat and fstat
	*/
istat(ip, buf)
	struct inode *ip;
	int *buf;
	{
	if (!valid(buf, 36))
		return;
	x4to3(&ip->size, &ip->size0);	/* update 3-byte size */
	copyout(ip, buf, 36);
	irelse(ip);
	}

       /*
	* Getpid system call
	*/
getpid()
	{
	return (procid(u.p));
	}

       /*
	* Stime system call
	*/
stime(high, low)
	unsigned high, low;
	{
	if (!super())
		return;
	di();
	seconds = ((long)high << 16) | low;
	ei();
	}

       /*
	* Seek system call
	* Seek(character-special, 0, 1 or 3) fails.
	*/
seek(fd, disp, from)
	int fd;
	fast int disp;
	fast unsigned from;
	{
	static struct file *fp;
	static long offset;

	if ((fp = ofile(fd)) == NULL)
		return;
	if (fp->mode & PIPE)
		{
		u.error = ESPIPE;
		return;
		}
	from %= 6;
	if (from == 0 || from == 3)
		offset = (unsigned) disp;
	else
		offset = disp;
	if (from >= 3)
		offset <<= 9;
	switch (from)
		{
	case 0:
	case 3:
		break;
	case 1:
	case 4:
		offset += fp->rwptr;
		break;
	case 2:
	case 5:
		offset += fp->inode->size;
		break;
		}
	if (offset < 0)
		u.error = EINVAL;
	else
		fp->rwptr = offset;
	}

       /*
	* Sleep system call (not internal sleep)
	*/
snooze(secs)
	fast unsigned int secs;
	{
	long waketime;
	extern int revel;

	di();
	waketime = seconds + secs;
	while (waketime > seconds)
		{
		secs = waketime - seconds;

		if (revel <= 0 || secs < revel)
			{
			revel = secs;
			}

		sleep(&revel, PRIUSER);
		di();
		}
	ei();
	}

	/*
	 * Alarm system call.
	 * Signal is sent in clock() (time.c).
	 */

alarm(secs)
	UINT secs;
	{
	static UINT old;

	old = u.p->alarm;
	u.p->alarm = secs;

	return old;
	}

	/*
	 * Pause system call
	 */
pause()
	{
	sleep(&pause, PRIUSER);
	}