/*
   =============================================================================
	mtid.c -- Multi-Tasker -- get next task ID
	Version 1 -- 1988-04-11 -- D.N. Lynx Crowe
	(c) Copyright 1988 -- D.N. Lynx Crowe
   =============================================================================
*/

#include "stddefs.h"
#include "biosdefs.h"
#include "mtdefs.h"
#include "debug.h"

extern	short		setipl();	/* set processor IPL function */

extern	struct _mtdef	*_MT_;		/* Multi-Tasker structure pointer */

/* 
*/

/*
   =============================================================================
	MTID() -- return next available task identifier
   =============================================================================
*/

unsigned
MTID()
{
	register short inuse, oldipl;
	register unsigned newtid;
	register TCB *tcp;

	inuse = TRUE;			/* preset inuse to get things started */

	if ((struct _mt_def *)NIL EQ _MT_)
		_MT_ = (struct _mt_def *)XBIOS(X_MTDEFS);

	oldipl = setipl(7);		/* DISABLE INTERRUPTS */

	while (inuse) {

		newtid = _MT_->mtp->IDct++;	/* pick the next ID to try */
		inuse = FALSE;		/* say it's not in use */
		tcp = _MT_->mtp->TCBs;	/* start search at beginning */

		while (tcp) {		/* search the TCB table */

			if (tcp->flags & MTF_OCC)		/* TCB occupied ? */
				if (tcp->tid EQ newtid) {	/* tid in use ? */

					inuse = TRUE;	/* set to search again */
					break;
				}

			tcp = tcp->fwd;
		}
	}

	setipl(oldipl);			/* RESTORE INTERRUPTS */

	return(newtid);			/* return the new task ID */
}