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2 pj 1
/*
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 * Project: S.Ha.R.K.
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 *
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 * Coordinators:
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 *   Giorgio Buttazzo    <giorgio@sssup.it>
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 *   Paolo Gai           <pj@gandalf.sssup.it>
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 *
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 * Authors     :
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 *   Paolo Gai           <pj@gandalf.sssup.it>
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 *   Massimiliano Giorgi <massy@gandalf.sssup.it>
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 *   Luca Abeni          <luca@gandalf.sssup.it>
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 *   (see the web pages for full authors list)
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 *
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 * ReTiS Lab (Scuola Superiore S.Anna - Pisa - Italy)
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 *
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 * http://www.sssup.it
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 * http://retis.sssup.it
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 * http://shark.sssup.it
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 */
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/*
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 * Copyright (C) 2000 Massimiliano Giorgi
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 *
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 * This program is free software; you can redistribute it and/or modify
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 * it under the terms of the GNU General Public License as published by
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 * the Free Software Foundation; either version 2 of the License, or
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 * (at your option) any later version.
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 *
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 * This program is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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 * GNU General Public License for more details.
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 *
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 * You should have received a copy of the GNU General Public License
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 * along with this program; if not, write to the Free Software
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 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
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 *
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 */
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#include "bqueue.h"
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#include "glue.h"
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int fcfs_init(fcfs_queue_t *q)
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{
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  __b_fastmutex_init(&q->mutex);
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  q->disk=NULL;
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  q->head=NULL;
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  q->tail=NULL;
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  q->counter=0;
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  return 0;
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}
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int fcfs_numelements(fcfs_queue_t *q)
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{
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  return q->counter;
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}
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int fcfs_insertrequest(fcfs_queue_t *q, request_prologue_t *e)
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{
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  //cprintf("Û%p into %pÛ",e,q);
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  __b_fastmutex_lock(&q->mutex);  
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  if (q->head==NULL) q->head=e;
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  else               q->tail->x.next=e;
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  q->tail=e;
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  e->x.next=NULL;
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  q->counter++;
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  __b_fastmutex_unlock(&q->mutex);
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  return 0;
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}
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request_prologue_t *fcfs_getrequest(fcfs_queue_t *q)
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{
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  request_prologue_t *ret;
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  //cprintf("Ûfrom %p have %pÛ",q,q->head);
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  __b_fastmutex_lock(&q->mutex);
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  ret=q->head;
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  __b_fastmutex_unlock(&q->mutex);
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  return ret;
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}
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int fcfs_removerequest(fcfs_queue_t *q)
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{
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  //cprintf("Ûremoved %p from %pÛ",q->head,q);
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  __b_fastmutex_lock(&q->mutex);
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  assertk(q->head!=NULL);
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  q->head=q->head->x.next;
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  q->counter--;
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  __b_fastmutex_unlock(&q->mutex);
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  return 0;
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}