/* kill.c - kill */

#include 

/*------------------------------------------------------------------------
 *  kill  -  Kill a process and remove it from the system
 *------------------------------------------------------------------------
 */
syscall kill(
          pid32         pid             /* ID of process to kill        */
        )
{
        intmask mask;                   /* Saved interrupt mask         */
        struct  procent *prptr;         /* Ptr to process's table entry */
        int32   i;                      /* Index into descriptors       */

        mask = disable();
        if (isbadpid(pid) || (pid == NULLPROC)
            || ((prptr = &proctab[pid])->prstate) == PR_FREE) {
                restore(mask);
                return SYSERR;
        }

        if (--prcount <= 1) {           /* Last user process completes  */
                xdone();
        }

        send(prptr->prparent, pid);
        for (i=0; i<3; i++) {
                close(prptr->prdesc[i]);
        }
        freestk(prptr->prstkbase, prptr->prstklen);

        switch (prptr->prstate) {
        case PR_CURR:
                prptr->prstate = PR_FREE;       /* Suicide */
                resched();

        case PR_SLEEP:
        case PR_RECTIM:
                unsleep(pid);
                prptr->prstate = PR_FREE;
                break;

        case PR_WAIT:
                semtab[prptr->prsem].scount++;
                /* Fall through */

        case PR_READY:
                getitem(pid);           /* Remove from queue */
                /* Fall through */

        default:
                prptr->prstate = PR_FREE;
        }

        restore(mask);
        return OK;
}