b48009644f
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5610 42af7a65-404d-4744-a932-0658087f49c3
133 lines
4.5 KiB
C
133 lines
4.5 KiB
C
/************************************************************************
|
|
* sched/sched_getscheduler.c
|
|
*
|
|
* Copyright (C) 2007, 2009 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 <sys/types.h>
|
|
#include <sched.h>
|
|
#include <errno.h>
|
|
|
|
#include <nuttx/arch.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 task identified by pid. If pid equals zero, the
|
|
* policy of the calling task 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)
|
|
{
|
|
struct tcb_s *tcb;
|
|
|
|
/* Verify that the pid corresponds to a real task */
|
|
|
|
if (!pid)
|
|
{
|
|
tcb = (struct tcb_s*)g_readytorun.head;
|
|
}
|
|
else
|
|
{
|
|
tcb = sched_gettcb(pid);
|
|
}
|
|
|
|
if (!tcb)
|
|
{
|
|
set_errno(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;
|
|
}
|
|
}
|
|
|