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/************************************************************
* task_create.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 <nuttx/config.h>
#include <sys/types.h>
#include <sched.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/arch.h>
#include "os_internal.h"
/************************************************************
* Definitions
************************************************************/
/************************************************************
* Private Type Declarations
************************************************************/
/************************************************************
* Global Variables
************************************************************/
/************************************************************
* Private Variables
************************************************************/
/************************************************************
* Private Function Prototypes
************************************************************/
/************************************************************
* Private Functions
************************************************************/
/************************************************************
* Name: task_create
*
* Description:
* This function creates and activates a new task with a
* specified priority and returns its system-assigned ID.
*
* The entry address entry is the address of the "main"
* function of the task. This function will be called once
* the C environment has been set up. The specified
* function will be called with four arguments. Should
* the specified routine return, a call to exit() will
* automatically be made.
*
* Note that four (and only four) arguments must be passed for
* the spawned functions.
*
* Input Parameters:
* name - Name of the new task
* priority - Priority of the new task
* stack_size - size (in bytes) of the stack needed
* entry - Entry point of a new task
* arg - A pointer to an array of input parameters.
* Up to CONFIG_MAX_TASK_ARG parameters may
* be provided. If fewer than CONFIG_MAX_TASK_ARG
* parameters are passed, the list should be
* terminated with a NULL argv[] value.
* If no parameters are required, argv may be
* NULL.
*
* Return Value:
* Returns the non-zero process ID of the new task or
* ERROR if memory is insufficient or the task cannot be
* created (errno is not set).
*
************************************************************/
#ifndef CONFIG_CUSTOM_STACK
int task_create(const char *name, int priority,
int stack_size, main_t entry, const char *argv[])
#else
int task_create(const char *name, int priority,
main_t entry, const char *argv[])
#endif
{
FAR _TCB *tcb;
STATUS status;
pid_t pid;
/* Allocate a TCB for the new task. */
tcb = (FAR _TCB*)kzmalloc(sizeof(_TCB));
if (!tcb)
{
*get_errno_ptr() = ENOMEM;
return ERROR;
}
/* Associate file descriptors with the new task */
#if CONFIG_NFILE_DESCRIPTORS > 0
if (sched_setuptaskfiles(tcb) != OK)
{
sched_releasetcb(tcb);
return ERROR;
}
#endif
/* Allocate the stack for the TCB */
#ifndef CONFIG_CUSTOM_STACK
status = up_create_stack(tcb, stack_size);
if (status != OK)
{
sched_releasetcb(tcb);
return ERROR;
}
#endif
/* Initialize the task control block */
status = task_schedsetup(tcb, priority, task_start, entry);
if (status != OK)
{
sched_releasetcb(tcb);
return ERROR;
}
/* Setup to pass parameters to the new task */
(void)task_argsetup(tcb, name, argv);
/* Get the assigned pid before we start the task */
pid = (int)tcb->pid;
/* Activate the task */
status = task_activate(tcb);
if (status != OK)
{
dq_rem((FAR dq_entry_t*)tcb, (dq_queue_t*)&g_inactivetasks);
sched_releasetcb(tcb);
return ERROR;
}
return pid;
}
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