nuttx/sched/sched_removereadytorun.c
patacongo b08a86171f NuttX RTOS
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@3 42af7a65-404d-4744-a932-0658087f49c3
2007-02-17 23:21:28 +00:00

118 lines
4.1 KiB
C

/************************************************************
* sched_removereadytorun.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 <sys/types.h>
#include <queue.h>
#include <assert.h>
#include "os_internal.h"
/************************************************************
* Definitions
************************************************************/
/************************************************************
* Private Type Declarations
************************************************************/
/************************************************************
* Global Variables
************************************************************/
/************************************************************
* Private Variables
************************************************************/
/************************************************************
* Private Function Prototypes
************************************************************/
/************************************************************
* Public Functions
************************************************************/
/************************************************************
* Name: sched_removereadytorun
*
* Description:
* This function removes a TCB from the ready to run list.
*
* Inputs:
* rtcb - Points to the TCB that is ready-to-run
*
* Return Value:
* TRUE if the currently active task (the head of the
* g_readytorun list) has changed.
*
* Assumptions:
* - The caller has established a critical section before
* calling this function (calling sched_lock() first is NOT
* a good idea -- use irqsave()).
* - The caller handles the condition that occurs if the
* the head of the g_readytorun list is changed.
************************************************************/
boolean sched_removereadytorun(_TCB *rtcb)
{
boolean ret = FALSE;
/* Check if the TCB to be removed is at the head of the ready
* to run list. In this case, we are removing the currently
* active task.
*/
if (!rtcb->blink)
{
ASSERT(rtcb->flink != NULL);
/* Inform the instrumentation layer that we are switching tasks */
sched_note_switch(rtcb, rtcb->flink);
rtcb->flink->task_state = TSTATE_TASK_RUNNING;
ret = TRUE;
}
/* Remove the TCB from the ready-to-run list */
dq_rem((dq_entry_t*)rtcb, &g_readytorun);
rtcb->task_state = TSTATE_TASK_INVALID;
return ret;
}