incubator-nuttx/sched/signal/sig_findaction.c

/****************************************************************************
 * sched/signal/sig_findaction.c
 *
 *   Copyright (C) 2007, 2009, 2016 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>
#include "signal/signal.h"

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: sig_findaction
 *
 * Description:
 *   Allocate a new element for a signal queue
 *
 ****************************************************************************/

FAR sigactq_t *sig_findaction(FAR struct task_group_s *group, int signo)
{
  FAR sigactq_t *sigact = NULL;

  /* Verify the caller's sanity */

  if (group)
    {
      /* Sigactions can only be assigned to the currently executing
       * thread.  So, a simple lock ought to give us sufficient
       * protection.
       */

      sched_lock();

      /* Seach the list for a sigaction on this signal */

      for (sigact = (FAR sigactq_t *)group->tg_sigactionq.head;
          ((sigact) && (sigact->signo != signo));
          sigact = sigact->flink);

      sched_unlock();
    }

  return sigact;
}