sched/task_activate.c

/****************************************************************************
 * sched/task_activate.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
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 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>

#include <sched.h>
#include <debug.h>
#include <nuttx/arch.h>

/****************************************************************************
 * Definitions
 ****************************************************************************/

/****************************************************************************
 * Private Type Declarations
 ****************************************************************************/

/****************************************************************************
 * Global Variables
 ****************************************************************************/

/****************************************************************************
 * Private Variables
 ****************************************************************************/

/****************************************************************************
 * Private Function Prototypes
 ****************************************************************************/

/****************************************************************************
 * Private Functions
 ****************************************************************************/

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: task_activate
 *
 * Description:
 *   This function activates tasks initialized by
 *   task_schedsetup(). Without activation, a task is
 *   ineligible for execution  by the scheduler.
 *
 * Input Parameters:
 *   tcb - The TCB for the task for the task (same as the
 *         task_init argument.
 *
 * Return Value:
 *  Always returns OK
 *
 ****************************************************************************/

int task_activate(FAR _TCB *tcb)
{
  irqstate_t flags = irqsave();

#ifdef CONFIG_SCHED_INSTRUMENTATION

  /* Check if this is really a re-start */

  if (tcb->task_state != TSTATE_TASK_INACTIVE)
    {
      /* Inform the instrumentation layer that the task
       * has stopped
       */

      sched_note_stop(tcb);
    }

  /* Inform the instrumentation layer that the task
   * has started
   */

  sched_note_start(tcb);
#endif

  up_unblock_task(tcb);
  irqrestore(flags);
  return OK;
}