signal_create.c

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/*
** Copyright (C) 2005 by Kevin L. Mitchell <klmitch@mit.edu>
**
** 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
**
** @(#)$Id: signal_create.c,v 1.2 2005/10/25 01:46:17 klmitch Exp $
*/
#include "engines_int.h"

#include <string.h>

RCSTAG("@(#)$Id: signal_create.c,v 1.2 2005/10/25 01:46:17 klmitch Exp $");

ev_err_t
signal_create(ev_ctx_t *ctx, int signal, ev_call_t call, void *data,
              ev_sig_t **sig_p)
{
  ev_engine_t *eng;
  ev_err_t err = 0;
  ev_sig_t *sig;

  ev_init(); /* make sure library is initialized... */

  /* sanity-check the arguments... */
  if (!ec_verify(ctx))
    ev_return(EINVAL);

  /* Let's allocate a generator... */
  if ((err = event_gen_alloc(ctx, EGT_SIGNAL, &sig)))
    ev_return(err);

  /* Set callback information */
  eg_callback_set(sig, call);
  eg_calldata_set(sig, data);

  /* Now initialize the signal fields... */
  memset(&sig->si_oact, 0, sizeof(sig->si_oact)); /* zero old action field */
  sig->si_signal = signal; /* set the signal */

  /* Walk through all signal engines... */
  for (eng = ctx->ec_signal.el_first; eng;
       eng = eng->eng_signal.esi_active.el_next)
    if ((err = eng_sig_add(ctx, eng, sig))) { /* add to engine... */
      /* oops!  Error occurred.  Walk engines backwards and remove signal */
      for (; eng; eng = eng->eng_signal.esi_active.el_prev)
        eng_sig_rem(ctx, eng, sig);

      event_gen_release(ctx, (ev_genhdr_t *)sig); /* release signal memory */

      ev_return(err); /* return the error */
    }

  eg_ref_inc(ctx, sig); /* increment the reference count */

  if (sig_p) /* did caller want signal? */
    *sig_p = sig; /* then return it */

  ev_return(0);
}

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