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/************************************************************
* sched_getscheduler.c
*
* Copyright (C) 2007 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 Gregory Nutt 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 <errno.h>
#include <nuttx/arch.h>
#include <nuttx/os_external.h>
#include "os_internal.h"
/************************************************************
* Definitions
************************************************************/
/************************************************************
* Private Type Declarations
************************************************************/
/************************************************************
* Global Variables
************************************************************/
/************************************************************
* Private Variables
************************************************************/
/************************************************************
* Private Function Prototypes
************************************************************/
/************************************************************
* Private Functions
************************************************************/
/************************************************************
* Public Functions
************************************************************/
/************************************************************
* Name: sched_getscheduler
*
* Description:
* sched_getscheduler() returns the scheduling policy
* currently applied to the process identified by pid. If
* pid equals zero, the policy of the calling process will
* be retrieved.
*
* Inputs:
* pid - the task ID of the task to query. If pid is
* zero, the calling task is queried.
*
* Return Value:
* On success, sched_getscheduler() returns the policy for
* the task (either SCHED_FIFO or SCHED_RR). On error,
* ERROR (-1) is returned, and errno is set appropriately:
*
* ESRCH The task whose ID is pid could not be found.
*
* Assumptions:
*
************************************************************/
int sched_getscheduler(pid_t pid)
{
_TCB *tcb;
/* Verify that the pid corresponds to a real task */
if (!pid)
{
tcb = (_TCB*)g_readytorun.head;
}
else
{
tcb = sched_gettcb(pid);
}
if (!tcb)
{
*get_errno_ptr() = ESRCH;
return ERROR;
}
#if CONFIG_RR_INTERVAL > 0
else if ((tcb->flags & TCB_FLAG_ROUND_ROBIN) != 0)
{
return SCHED_RR;
}
#endif
else
{
return SCHED_FIFO;
}
}
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