/*
   =============================================================================
	mtstat.c -- Multi-Tasker -- task status check
	Version 4 -- 1988-04-14 -- D.N. Lynx Crowe
	(c) Copyright 1988 -- D.N. Lynx Crowe
   =============================================================================
*/

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

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

extern	struct _mt_def	*_MT_;

/* 
*/

/*
   =============================================================================
	MTStat() -- check task status

		-3	stopped, waiting on a sempahore
		-2	stopped, not waiting
		-1	not found
		 0	running  (current task)
		 1	ready to run
		 2	waiting on a sempahore
   =============================================================================
*/

short
MTStat(tid)
unsigned tid;
{
	register TCB *tcp;
	register short oldipl, rv;

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

	tcp = _MT_->mtp->TCBs;		/* point at start of  TCB list */
	rv = -1;			/* preset return value */

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

	while (tcp) {			/* check each TCB */

		if (tcp->flags & MTF_OCC) {		/* occupied ? */

			if (tcp->tid NE tid)		/* continue if not tid */
				goto nexttcb;

			if (tcp->flags & MTF_RUN) {	/* running ? */

				rv = 0;
				break;
			}

			if (tcp->flags & MTF_RDY) {	/* ready to run ? */

				rv = 1;
				break;
			}

			if (tcp->flags & MTF_STP) {	/* to be stopped ? */

				rv = -3;
				break;
			}

			if (tcp->flags & MTF_SWT) {	/* waiting ? */

				rv = 2;
				break;
			}

			rv = -2;			/* stopped */
			break;
		}

nexttcb:
		tcp = tcp->fwd;					/* look at next TCB */
	}

	setipl(oldipl);				/* RESTORE INTERRUPTS */

	return(rv);				/* return status of task */
}