text: /****************************************************************************
   * sched/signal/sig_mqnotempty.c
   *
   *   Copyright (C) 2007-2009, 2013, 2015 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
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
   * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
   * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
   * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
   * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
   * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
   * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
   * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   *
   ****************************************************************************/
  
  /****************************************************************************
   * Included Files
   ****************************************************************************/
  
  #include <nuttx/config.h>
  #include <nuttx/compiler.h>
  
  #include <signal.h>
  #include <sched.h>
  #include <errno.h>
  #include <debug.h>
  
  #include "sched/sched.h"
  #include "signal/signal.h"
  
  /****************************************************************************
   * Public Functions
   ****************************************************************************/
  
  /****************************************************************************
   * Name: sig_mqnotempty
   *
   * Description:
   *   This function is equivalent to sigqueue(), but supports the messaging
   *   system's requirement to signal a task when a message queue becomes
   *   non-empty.  It is identical to sigqueue(), except that it sets the
   *   si_code field in the siginfo structure to SI_MESGQ rather than SI_QUEUE.
   *
   ****************************************************************************/
  
  #ifdef CONFIG_CAN_PASS_STRUCTS
  int sig_mqnotempty(int pid, int signo, union sigval value)
  #else
  int sig_mqnotempty(int pid, int signo, void *sival_ptr)
  #endif
  {
  #ifdef CONFIG_SCHED_HAVE_PARENT
    FAR struct tcb_s *rtcb = this_task();
  #endif
    siginfo_t info;
    int ret;
  
  #ifdef CONFIG_CAN_PASS_STRUCTS
    sdbg("pid=%p signo=%d value=%d\n", pid, signo, value.sival_int);
  #else
    sdbg("pid=%p signo=%d sival_ptr=%p\n", pid, signo, sival_ptr);
  #endif
  
    /* Verify that we can perform the signalling operation */
  
    if (!GOOD_SIGNO(signo))
      {
        return -EINVAL;
      }
  
    /* Create the siginfo structure */
  
    info.si_signo           = signo;
    info.si_code            = SI_MESGQ;
    info.si_errno           = OK;
  #ifdef CONFIG_CAN_PASS_STRUCTS
    info.si_value           = value;
  #else
    info.si_value.sival_ptr = sival_ptr;
  #endif
  #ifdef CONFIG_SCHED_HAVE_PARENT
    info.si_pid             = rtcb->pid;
    info.si_status          = OK;
  #endif
  
    /* Process the receipt of the signal */
  
    sched_lock();
    ret = sig_dispatch(pid, &info);
    sched_unlock();
  
    return ret;
  }
  