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/*

 * Project: S.Ha.R.K.

 *

 * Coordinators:

 *   Giorgio Buttazzo    <giorgio@sssup.it>

 *   Paolo Gai           <pj@gandalf.sssup.it>

 *

 * Authors     :

 *   Paolo Gai           <pj@gandalf.sssup.it>

 *   (see the web pages for full authors list)

 *

 * ReTiS Lab (Scuola Superiore S.Anna - Pisa - Italy)

 *

 * http://www.sssup.it

 * http://retis.sssup.it

 * http://shark.sssup.it

 */

/**

 ------------

 CVS :        $Id: nanoslp.c,v 1.1.1.1 2002-03-29 14:12:52 pj Exp $

 File:        $File$

 Revision:    $Revision: 1.1.1.1 $

 Last update: $Date: 2002-03-29 14:12:52 $

 ------------

 This file contains the nanosleep function (posix 14.2.5) and related

 functions

**/

/*

 * Copyright (C) 2000 Paolo Gai

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 *

 */

#include <stdarg.h>

#include <ll/ll.h>

#include <ll/stdlib.h>

#include <ll/stdio.h>

#include <ll/string.h>

#include <kernel/config.h>

#include <kernel/model.h>

#include <kernel/const.h>

#include <sys/types.h>

#include <kernel/types.h>

#include <kernel/descr.h>

#include <errno.h>

#include <kernel/var.h>

#include <kernel/func.h>

static int nanosleep_once = 1;

/* this table is used to store the wakeup time of the task,

   because if the rmtp argument is specified, the remaining sleep time

   have to be returned. */

struct timespec nanosleep_table[MAX_PROC];

/* this is the test that is done when a task is being killed

   and it is waiting on a sigwait */

static int nanosleep_cancellation_point(PID i, void *arg)

{

    LEVEL l;

    if (proc_table[i].status == WAIT_NANOSLEEP) {

      /* the task that have to be killed is waiting on a nanosleep */

      /* the nanosleep event have to be removed */

      event_delete(proc_table[i].delay_timer);

      proc_table[i].delay_timer = -1;

      /* and the task have to be reinserted into the ready queues, so it

         will fall into task_testcancel */

      l = proc_table[i].task_level;

      level_table[l]->task_insert(l,i);

      return 1;

    }

    return 0;

}

int nanosleep_interrupted_by_signal(PID i, void *arg)

{

    LEVEL l;

    struct timespec t1, t2;

    if (proc_table[i].status == WAIT_NANOSLEEP) {

      /* the task is waiting on a nanosleep and it is still receiving a

         signal... */

      ll_gettime(TIME_EXACT,&t1);

      SUBTIMESPEC(&nanosleep_table[i], &t1, &t2);

      TIMESPEC_ASSIGN(&nanosleep_table[i], &t2);

      /* the nanosleep event have to be removed */

      event_delete(proc_table[i].delay_timer);

      proc_table[i].delay_timer = -1;

      /* and the task have to be reinserted into the ready queues, so it

         will fall into task_testcancel */

      l = proc_table[i].task_level;

      level_table[l]->task_insert(l,i);

      return 1;

    }

    return 0;

}

static void nanosleep_timer(void *arg)

{

  PID p = (PID)arg;

  LEVEL l;

  NULL_TIMESPEC(&nanosleep_table[p]);

  proc_table[p].delay_timer = -1;

  l = proc_table[p].task_level;

  level_table[l]->task_insert(l,p);

  event_need_reschedule();

}

int nanosleep(const struct timespec *rqtp, struct timespec *rmtp)

{

  struct timespec ty;

  TIME tx;

  LEVEL l;

  if (rqtp->tv_sec < 0 || rqtp->tv_nsec > 1000000000)

    return EINVAL;

  proc_table[exec_shadow].context = kern_context_save();

  /* first, if it is the first time that the nanosleep is called,

     register the cancellation point */

  if (nanosleep_once) {

    nanosleep_once = 0;

    register_cancellation_point(nanosleep_cancellation_point, NULL);

    register_interruptable_point(nanosleep_interrupted_by_signal, NULL);

  }

  /* SAME AS SCHEDULER... manage the capacity event and the load_info */

  ll_gettime(TIME_EXACT, &schedule_time);

  SUBTIMESPEC(&schedule_time, &cap_lasttime, &ty);

  tx = TIMESPEC2USEC(&ty);

  proc_table[exec_shadow].avail_time -= tx;

  jet_update_slice(tx);

  if (cap_timer != NIL) {

    event_delete(cap_timer);

    cap_timer = NIL;

  }

  /* now, we block the current task, waiting the end of the target task */

  l = proc_table[exec_shadow].task_level;

  level_table[l]->task_extract(l,exec_shadow);

  proc_table[exec_shadow].status = WAIT_NANOSLEEP;

  ADDTIMESPEC(&schedule_time, rqtp, &nanosleep_table[exec_shadow]);

  /* we can use the delaytimer because if we are here we are not in a

     task_delay */

  proc_table[exec_shadow].delay_timer =

    kern_event_post(&nanosleep_table[exec_shadow],

                    nanosleep_timer,

                    (void *)exec_shadow);

  exec = exec_shadow = -1;

  scheduler();

  kern_context_load(proc_table[exec_shadow].context);

  task_testcancel();

  /* if the nanosleep_table[exec_shadow] != {0,0}, the nanosleep was

     interrupted by a signal... */

  if (nanosleep_table[exec_shadow].tv_sec  != 0 ||

      nanosleep_table[exec_shadow].tv_nsec != 0    ) {

    if (rmtp)

      TIMESPEC_ASSIGN(rmtp, &nanosleep_table[exec_shadow]);

    return (EINTR);

  }

  else

    return 0;

}

unsigned int sleep(unsigned int seconds)

{

  struct timespec t, t2;

  t.tv_sec = seconds;

  t.tv_nsec = 0;

  nanosleep(&t, &t2);

  return t2.tv_sec;

}