/************************************************************************
* up_releasepending.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 <sched.h>
#include <debug.h>
#include <nuttx/arch.h>
#include "os_internal.h"
#include "up_internal.h"
/************************************************************************
* Private Definitions
************************************************************************/
/************************************************************************
* Private Data
************************************************************************/
/************************************************************************
* Private Funtions
************************************************************************/
/************************************************************************
* Public Funtions
************************************************************************/
/************************************************************************
* Name: up_release_pending
*
* Description:
* Release and ready-to-run tasks that have
* collected in the pending task list. This can call a
* context switch if a new task is placed at the head of
* the ready to run list.
*
************************************************************************/
void up_release_pending(void)
{
FAR _TCB *rtcb = (FAR _TCB*)g_readytorun.head;
dbg("From TCB=%p\n", rtcb);
/* Merge the g_pendingtasks list into the g_readytorun task list */
/* sched_lock(); */
if (sched_mergepending())
{
/* The currently active task has changed! We will need to
* switch contexts. First check if we are operating in
* interrupt context:
*/
if (g_irqtos)
{
/* Yes, then we have to do things differently.
* Just copy the current registers into the OLD rtcb.
*/
up_saveirqcontext(&rtcb->xcp);
/* Restore the exception context of the rtcb at the (new) head
* of the g_readytorun task list.
*/
rtcb = (FAR _TCB*)g_readytorun.head;
dbg("New Active Task TCB=%p\n", rtcb);
/* Then setup so that the context will be performed on exit
* from the interrupt.
*/
g_irqcontext = &rtcb->xcp;
}
/* Copy the exception context into the TCB of the task that
* was currently active. if up_savecontext returns a non-zero
* value, then this is really the previously running task
* restarting!
*/
else if (!up_savecontext(&rtcb->xcp))
{
/* Restore the exception context of the rtcb at the (new) head
* of the g_readytorun task list.
*/
rtcb = (FAR _TCB*)g_readytorun.head;
dbg("New Active Task TCB=%p\n", rtcb);
/* Then switch contexts */
up_restorecontext(&rtcb->xcp);
}
}
}
