nuttx/sched/group_create.c

/*****************************************************************************
 * sched/group_create.c
 *
 *   Copyright (C) 2013 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 <assert.h>
#include <errno.h>
#include <debug.h>

#include <nuttx/kmalloc.h>

#ifdef HAVE_TASK_GROUP

/*****************************************************************************
 * Pre-processor Definitions
 *****************************************************************************/

/*****************************************************************************
 * Private Types
 *****************************************************************************/

/*****************************************************************************
 * Private Data
 *****************************************************************************/

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

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

/*****************************************************************************
 * Name: group_create
 *
 * Description:
 *   Create and initialize a new task group structure for the specified TCB.
 *   This function is called as part of the task creation sequence.
 *
 * Parameters:
 *   tcb - The tcb in need of the task group.
 *
 * Return Value:
 *   0 (OK) on success; a negated errno value on failure.
 *
 * Assumptions:
 *   Called during task creation in a safe context.  No special precautions
 *   are required here.
 *
 *****************************************************************************/

int group_create(FAR _TCB *tcb)
{
  FAR struct task_group_s *group;

  DEBUGASSERT(tcb && !tcb->group);

  /* Allocate the group structure */

  group = (FAR struct task_group_s *)kzalloc(sizeof(struct task_group_s));
  if (!group)
    {
      return -ENOMEM;
    }

  /* Initialize the group structure and assign it to the tcb */

  group->tg_crefs = 1;
  tcb->group      = group;
  return OK;
}

#endif /* HAVE_TASK_GROUP */