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/*

 *  3.3.4 Examine and Change Signal Action, P1003.1b-1993, p. 70

 *

 *  COPYRIGHT (c) 1989-1999.

 *  On-Line Applications Research Corporation (OAR).

 *

 *  The license and distribution terms for this file may be

 *  found in the file LICENSE in this distribution or at

 *  http://www.OARcorp.com/rtems/license.html.

 *

 *  sigaction.c,v 1.7 2002/01/04 18:28:24 joel Exp

 */

#if HAVE_CONFIG_H

#include "config.h"

#endif

#include <pthread.h>

#include <signal.h>

#include <errno.h>

#include <rtems/system.h>

#include <rtems/posix/pthread.h>

#include <rtems/posix/psignal.h>

#include <rtems/seterr.h>

#include <rtems/score/isr.h>

/*

 * PARAMETERS_PASSING_S is defined in ptimer.c

 */

extern void PARAMETERS_PASSING_S (int num_signal, const struct sigaction inf);

int sigaction(

  int                     sig,

  const struct sigaction *act,

  struct sigaction       *oact

)

{

  ISR_Level     level;

  if ( oact )

    *oact = _POSIX_signals_Vectors[ sig ];

  if ( !sig )

    return 0;

  if ( !is_valid_signo(sig) )

    rtems_set_errno_and_return_minus_one( EINVAL );

  /*

   *  Some signals cannot be ignored (P1003.1b-1993, pp. 70-72 and references.

   *

   *  NOTE: Solaris documentation claims to "silently enforce" this which

   *        contradicts the POSIX specification.

   */

  if ( sig == SIGKILL )

    rtems_set_errno_and_return_minus_one( EINVAL );

  /*

   *  Evaluate the new action structure and set the global signal vector

   *  appropriately.

   */

  if ( act ) {

    /*

     *  Unless the user is installing the default signal actions, then

     *  we can just copy the provided sigaction structure into the vectors.

     */

    _ISR_Disable( level );

      if ( act->sa_handler == SIG_DFL ) {

        _POSIX_signals_Vectors[ sig ] = _POSIX_signals_Default_vectors[ sig ];

      } else {

         _POSIX_signals_Clear_process_signals( signo_to_mask(sig) );

         _POSIX_signals_Vectors[ sig ] = *act;

      }

    _ISR_Enable( level );

  }

  /*

   *  No need to evaluate or dispatch because:

   *

   *    + If we were ignoring the signal before, none could be pending

   *      now (signals not posted when SIG_IGN).

   *    + If we are now ignoring a signal that was previously pending,

   *      we clear the pending signal indicator.

   */

  return 0;

}