Desktop/xinu_mips-1.0.2.tar/xinu_mips-1.0.2/system/kill.c

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/* Embedded XINU, Copyright (C) 2007.  All rights reserved. */

#include <kernel.h>
#include <proc.h>
#include <queue.h>
#include <semaphore.h>
#include <memory.h>

extern void xdone(void);

/*
 * kill  --  kill a process and remove it from the system
 */
syscall kill(int pid)
{
        irqmask ps;
        pcb     *ppcb;  /* points to process control block for pid */

        if ( isbadpid(pid) || (0 == pid)
                || (PRFREE == (ppcb = &proctab[pid])->state) )
        { return SYSERR; }
        ps = disable();
        if (isbadpid(pid))
        {
                restore(ps);
                return SYSERR;
        }
        ppcb = &proctab[pid];

        --numproc;

        send(ppcb->parent, pid, BLOCK);

        freemem(ppcb->stkbase);

        switch (ppcb->state)
        {
        case PRCURR:
                ppcb->state = PRFREE;   /* suicide */
                resched();

        case PRWAIT:
                semtab[ppcb->sem].count++;

        case PRSLEEP: 
        case PRREADY:
                remove(pid);

        default:
                ppcb->state = PRFREE;
        }

        restore(ps);
        return OK;
}

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