/************************************************************************
* sched/sched_getparam.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 <sys/types.h>
#include <sched.h>
#include "os_internal.h"
/************************************************************************
* Definitions
************************************************************************/
/************************************************************************
* Private Type Declarations
************************************************************************/
/************************************************************************
* Global Variables
************************************************************************/
/************************************************************************
* Private Variables
************************************************************************/
/************************************************************************
* Private Function Prototypes
************************************************************************/
/************************************************************************
* Private Functions
************************************************************************/
/************************************************************************
* Public Functions
************************************************************************/
/************************************************************************
* Name: sched_getparam
*
* Description:
* This function gets the scheduling priority of the task
* specified by pid.
*
* Inputs:
* pid - the task ID of the task. If pid is zero, the priority
* of the calling task is returned.
* param - A structure whose member sched_priority is the integer
* priority. The task's priority is copied to the sched_priority
* element of this structure.
*
* Return Value:
* 0 (OK) if successful, otherwise -1 (ERROR).
*
* This function can fail if param is null or if pid does
* not correspond to any task.
*
* Assumptions:
*
************************************************************************/
int sched_getparam (pid_t pid, struct sched_param * param)
{
FAR _TCB *rtcb;
FAR _TCB *tcb;
int ret = OK;
if (!param)
{
return ERROR;
}
/* Check if the task to restart is the calling task */
rtcb = (FAR _TCB*)g_readytorun.head;
if ((pid == 0) || (pid == rtcb->pid))
{
/* Return the priority if the calling task. */
param->sched_priority = (int)rtcb->sched_priority;
}
/* Ths pid is not for the calling task, we will have to look it up */
else
{
/* Get the TCB associated with this pid */
sched_lock();
tcb = sched_gettcb(pid);
if (!tcb)
{
/* This pid does not correspond to any known task */
ret = ERROR;
}
else
{
/* Return the priority of the task */
param->sched_priority = (int)tcb->sched_priority;
}
sched_unlock();
}
return ret;
}
