Пример #1
0
/*
 *  The abstime is a walltime.  We turn it into an interval.
 */
TOD_Absolute_timeout_conversion_results _TOD_Absolute_timeout_to_ticks(
  const struct timespec *abstime,
  Watchdog_Interval     *ticks_out
)
{
  struct timespec current_time;
  struct timespec difference;


  /*
   *  Make sure there is always a value returned.
   */
  *ticks_out = 0;

  /*
   *  Is the absolute time even valid?
   */
  if ( !_Timespec_Is_valid(abstime) )
    return TOD_ABSOLUTE_TIMEOUT_INVALID;

  /*
   *  Is the absolute time in the past?
   */
  _TOD_Get_as_timespec( &current_time );

  if ( _Timespec_Less_than( abstime, &current_time ) )
    return TOD_ABSOLUTE_TIMEOUT_IS_IN_PAST;

  /*
   *  How long until the requested absolute time?
   */
  _Timespec_Subtract( &current_time, abstime, &difference );

  /*
   *  Internally the SuperCore uses ticks, so convert to them.
   */
  *ticks_out = _Timespec_To_ticks( &difference );

  /*
   *  If the difference was 0, then the future is now.  It is so bright
   *  we better wear shades.
   */
  if ( !*ticks_out )
    return TOD_ABSOLUTE_TIMEOUT_IS_NOW;

  /*
   *  This is the case we were expecting and it took this long to
   *  get here.
   */
  return TOD_ABSOLUTE_TIMEOUT_IS_IN_FUTURE;
}
int sigtimedwait(
  const sigset_t         *set,
  siginfo_t              *info,
  const struct timespec  *timeout
)
{
  Thread_Control    *the_thread;
  POSIX_API_Control *api;
  Watchdog_Interval  interval;
  siginfo_t          signal_information;
  siginfo_t         *the_info;
  int                signo;
  ISR_Level          level;

  /*
   *  Error check parameters before disabling interrupts.
   */
  if ( !set )
    rtems_set_errno_and_return_minus_one( EINVAL );

  /*  NOTE: This is very specifically a RELATIVE not ABSOLUTE time
   *        in the Open Group specification.
   */

  interval = 0;
  if ( timeout ) {

    if ( !_Timespec_Is_valid( timeout ) )
      rtems_set_errno_and_return_minus_one( EINVAL );

    interval = _Timespec_To_ticks( timeout );

    if ( !interval )
      rtems_set_errno_and_return_minus_one( EINVAL );
  }

  /*
   *  Initialize local variables.
   */

  the_info = ( info ) ? info : &signal_information;

  the_thread = _Thread_Executing;

  api = the_thread->API_Extensions[ THREAD_API_POSIX ];

  /*
   *  What if they are already pending?
   */

  /* API signals pending? */

  _ISR_Disable( level );
  if ( *set & api->signals_pending ) {
    /* XXX real info later */
    the_info->si_signo = _POSIX_signals_Get_highest( api->signals_pending );
    _POSIX_signals_Clear_signals(
      api,
      the_info->si_signo,
      the_info,
      false,
      false
    );
    _ISR_Enable( level );

    the_info->si_code = SI_USER;
    the_info->si_value.sival_int = 0;
    return the_info->si_signo;
  }

  /* Process pending signals? */

  if ( *set & _POSIX_signals_Pending ) {
    signo = _POSIX_signals_Get_highest( _POSIX_signals_Pending );
    _POSIX_signals_Clear_signals( api, signo, the_info, true, false );
    _ISR_Enable( level );

    the_info->si_signo = signo;
    the_info->si_code = SI_USER;
    the_info->si_value.sival_int = 0;
    return signo;
  }

  the_info->si_signo = -1;

  _Thread_Disable_dispatch();
    the_thread->Wait.queue           = &_POSIX_signals_Wait_queue;
    the_thread->Wait.return_code     = EINTR;
    the_thread->Wait.option          = *set;
    the_thread->Wait.return_argument = the_info;
    _Thread_queue_Enter_critical_section( &_POSIX_signals_Wait_queue );
    _ISR_Enable( level );
    _Thread_queue_Enqueue( &_POSIX_signals_Wait_queue, interval );
  _Thread_Enable_dispatch();

  /*
   * When the thread is set free by a signal, it is need to eliminate
   * the signal.
   */

  _POSIX_signals_Clear_signals( api, the_info->si_signo, the_info, false, false );
  errno = _Thread_Executing->Wait.return_code;
  return the_info->si_signo;
}
Пример #3
0
/*
 *  14.2.5 High Resolution Sleep, P1003.1b-1993, p. 269
 */
int nanosleep(
  const struct timespec  *rqtp,
  struct timespec        *rmtp
)
{
  /*
   * It is critical to obtain the executing thread after thread dispatching is
   * disabled on SMP configurations.
   */
  Thread_Control *executing;

  Watchdog_Interval  ticks;
  Watchdog_Interval  elapsed;


  /*
   *  Return EINVAL if the delay interval is negative.
   *
   *  NOTE:  This behavior is beyond the POSIX specification.
   *         FSU and GNU/Linux pthreads shares this behavior.
   */
  if ( !_Timespec_Is_valid( rqtp ) )
    rtems_set_errno_and_return_minus_one( EINVAL );

  /*
   * Convert the timespec delay into the appropriate number of clock ticks.
   */
  ticks = _Timespec_To_ticks( rqtp );

  /*
   *  A nanosleep for zero time is implemented as a yield.
   *  This behavior is also beyond the POSIX specification but is
   *  consistent with the RTEMS API and yields desirable behavior.
   */
  if ( !ticks ) {
    _Thread_Disable_dispatch();
      executing = _Thread_Executing;
      _Thread_Yield( executing );
    _Thread_Enable_dispatch();
    if ( rmtp ) {
       rmtp->tv_sec = 0;
       rmtp->tv_nsec = 0;
    }
    return 0;
  }

  /*
   *  Block for the desired amount of time
   */
  _Thread_Disable_dispatch();
    executing = _Thread_Executing;
    _Thread_Set_state(
      executing,
      STATES_DELAYING | STATES_INTERRUPTIBLE_BY_SIGNAL
    );
    _Watchdog_Initialize(
      &executing->Timer,
      _Thread_Delay_ended,
      0,
      executing
    );
    _Watchdog_Insert_ticks( &executing->Timer, ticks );
  _Thread_Enable_dispatch();

  /*
   * Calculate the time that passed while we were sleeping and how
   * much remains from what we requested.
   */
  elapsed = executing->Timer.stop_time - executing->Timer.start_time;
  if ( elapsed >= ticks )
    ticks = 0;
  else
    ticks -= elapsed;

  /*
   * If the user wants the time remaining, do the conversion.
   */
  if ( rmtp ) {
    _Timespec_From_ticks( ticks, rmtp );
  }

  /*
   *  Only when POSIX is enabled, can a sleep be interrupted.
   */
  #if defined(RTEMS_POSIX_API)
    /*
     *  If there is time remaining, then we were interrupted by a signal.
     */
    if ( ticks )
      rtems_set_errno_and_return_minus_one( EINTR );
  #endif

  return 0;
}
Пример #4
0
int nanosleep(
  const struct timespec  *rqtp,
  struct timespec        *rmtp
)
{
  Watchdog_Interval  ticks;


  /*
   *  Return EINVAL if the delay interval is negative.
   *
   *  NOTE:  This behavior is beyond the POSIX specification.
   *         FSU and GNU/Linux pthreads shares this behavior.
   */
  if ( !_Timespec_Is_valid( rqtp ) )
    rtems_set_errno_and_return_minus_one( EINVAL );

  ticks = _Timespec_To_ticks( rqtp );

  /*
   *  A nanosleep for zero time is implemented as a yield.
   *  This behavior is also beyond the POSIX specification but is
   *  consistent with the RTEMS API and yields desirable behavior.
   */

  if ( !ticks ) {
    _Thread_Disable_dispatch();
      _Scheduler_Yield();
    _Thread_Enable_dispatch();
    if ( rmtp ) {
       rmtp->tv_sec = 0;
       rmtp->tv_nsec = 0;
    }
    return 0;
  }

  /*
   *  Block for the desired amount of time
   */
  _Thread_Disable_dispatch();
    _Thread_Set_state(
      _Thread_Executing,
      STATES_DELAYING | STATES_INTERRUPTIBLE_BY_SIGNAL
    );
    _Watchdog_Initialize(
      &_Thread_Executing->Timer,
      _Thread_Delay_ended,
      _Thread_Executing->Object.id,
      NULL
    );
    _Watchdog_Insert_ticks( &_Thread_Executing->Timer, ticks );
  _Thread_Enable_dispatch();

  /* calculate time remaining */

  if ( rmtp ) {
    ticks -=
      _Thread_Executing->Timer.stop_time - _Thread_Executing->Timer.start_time;

    _Timespec_From_ticks( ticks, rmtp );

    /*
     *  Only when POSIX is enabled, can a sleep be interrupted.
     */
    #if defined(RTEMS_POSIX_API)
        /*
         *  If there is time remaining, then we were interrupted by a signal.
         */
        if ( ticks )
          rtems_set_errno_and_return_minus_one( EINTR );
    #endif
  }

  return 0;
}