px4-firmware/nuttx/sched/sig_queue.c

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/****************************************************************************
* sched/sig_queue.c
*
* Copyright (C) 2007-2009 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* 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 <debug.h>
#include <sched.h>
#include <errno.h>
#include "os_internal.h"
#include "sig_internal.h"
/****************************************************************************
* Definitions
****************************************************************************/
/****************************************************************************
* Private Type Declarations
****************************************************************************/
/****************************************************************************
* Global Variables
****************************************************************************/
/****************************************************************************
* Private Variables
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Function: sigqueue
*
* Description:
* This function sends the signal specified by signo with
* the signal parameter value to the process specified by
* pid.
*
* If the receiving process has the signal blocked via the
* sigprocmask, the signal will pend until it is unmasked.
* Only one pending signal (per signo) is retained. This
* is consistent with POSIX which states, "If a subsequent
* occurrence of a pending signal is generated, it is
* implementation defined as to whether the signal is
* delivered more than once."
*
* Parameters:
* pid - Process ID of task to receive signal
* signo - Signal number
* value - Value to pass to task with signal
*
* Return Value:
* On success (at least one signal was sent), zero is
* returned. On error, -1 is returned, and errno is set
* appropriately.
*
* EGAIN The limit of signals which may be queued has been reached.
* EINVAL sig was invalid.
* EPERM The process does not have permission to send the
* signal to the receiving process.
* ESRCH No process has a PID matching pid.
*
* Assumptions:
*
****************************************************************************/
#ifdef CONFIG_CAN_PASS_STRUCTS
int sigqueue (int pid, int signo, union sigval value)
#else
int sigqueue(int pid, int signo, void *sival_ptr)
#endif
{
FAR _TCB *stcb;
siginfo_t info;
int ret = ERROR;
/* sanity checks */
if (!GOOD_SIGNO(signo))
{
*get_errno_ptr() = EINVAL;
return ERROR;
}
sched_lock();
/* Get the TCB of the receiving task */
stcb = sched_gettcb(pid);
#ifdef CONFIG_CAN_PASS_STRUCTS
sdbg("TCB=0x%08x signo=%d value=%d\n", stcb, signo, value.sival_int);
#else
sdbg("TCB=0x%08x signo=%d value=%p\n", stcb, signo, sival_ptr);
#endif
if (pid == 0 || !stcb)
{
*get_errno_ptr() = ESRCH;
sched_unlock();
return ERROR;
}
/* Create the siginfo structure */
info.si_signo = signo;
info.si_code = SI_QUEUE;
#ifdef CONFIG_CAN_PASS_STRUCTS
info.si_value = value;
#else
info.si_value.sival_ptr = sival_ptr;
#endif
/* Send the signal */
ret = sig_received(stcb, &info);
sched_unlock();
return ret;
}