/*
   =============================================================================
	mtzap.c -- Multi-Tasker -- free a TCB
	Version 3 -- 1988-04-14 -- 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 */

/* 
*/

/*
   =============================================================================
	MTZap() -- delete a task  (free its TCB)

		-1	not deleted	(was active or waiting)
		 0	deleted
		 1	not found
   =============================================================================
*/

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

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

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

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

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

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

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

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

				rv = -1;	/* not stopped */
				break;
			}

			tcp->flags = 0;		/* free the TCB */
			rv = 0;			/* TCB deleted */
			break;
		}

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

	setipl(oldipl);			/* RESTORE INTERRUPTS */

	return(rv);			/* return deletion status */
}