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

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

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

short insert(short pid, queue q, short key)
{
        short next;                     /* runs through list            */
        short prev;
        short head, tail;

        if (isbadqueue(q) || isbadpid(pid))
        { return SYSERR; }

        head = queuehead(q);
        tail = queuetail(q);

        next = queuetab[head].next;
        while ( (queuetab[next].key >= key) && (next != tail) )
        { next = queuetab[next].next; }

        queuetab[pid].next = next;
        queuetab[pid].prev = prev = queuetab[next].prev;
        queuetab[pid].key  = key;
        queuetab[prev].next = pid;
        queuetab[next].prev = pid;
        return OK;
}

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