px4-firmware/nuttx/sched/task_create.c

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/****************************************************************************
* sched/task_create.c
*
* Copyright (C) 2007-2010 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
* 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 <nuttx/kmalloc.h>
#include "os_internal.h"
#include "env_internal.h"
/****************************************************************************
* Definitions
****************************************************************************/
/****************************************************************************
* Private Type Declarations
****************************************************************************/
/****************************************************************************
* Global Variables
****************************************************************************/
/****************************************************************************
* Private Variables
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: thread_create
*
* Description:
* This function creates and activates a new thread of the specified type
* with a specified priority and returns its system-assigned ID. It is the
* internal, commn implementation of task_create() and kernel_thread(). See
* comments with task_create() for further information.
*
* Input Parameters:
* name - Name of the new task
* type - Type 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. The errno will be set to
* indicate the nature of the error (always ENOMEM).
*
****************************************************************************/
#ifndef CONFIG_CUSTOM_STACK
static int thread_create(const char *name, uint8_t type, int priority,
int stack_size, main_t entry, const char **argv)
#else
static int thread_create(const char *name, uint8_t type, int priority,
main_t entry, const char **argv)
#endif
{
FAR _TCB *tcb;
pid_t pid;
int ret;
/* Allocate a TCB for the new task. */
tcb = (FAR _TCB*)kzalloc(sizeof(_TCB));
if (!tcb)
{
goto errout;
}
/* Associate file descriptors with the new task */
#if CONFIG_NFILE_DESCRIPTORS > 0 || CONFIG_NSOCKET_DESCRIPTORS > 0
ret = sched_setuptaskfiles(tcb);
if (ret != OK)
{
goto errout_with_tcb;
}
#endif
/* Clone the parent's task environment */
(void)env_dup(tcb);
/* Allocate the stack for the TCB */
#ifndef CONFIG_CUSTOM_STACK
ret = up_create_stack(tcb, stack_size);
if (ret != OK)
{
goto errout_with_tcb;
}
#endif
/* Mark the type of this thread (this setting will be needed in
* task_schedsetup() when up_initial_state() is called.
*/
tcb->flags |= type;
/* Initialize the task control block */
ret = task_schedsetup(tcb, priority, task_start, entry);
if (ret != OK)
{
goto errout_with_tcb;
}
/* 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 */
ret = task_activate(tcb);
if (ret != OK)
{
dq_rem((FAR dq_entry_t*)tcb, (dq_queue_t*)&g_inactivetasks);
goto errout_with_tcb;
}
return pid;
errout_with_tcb:
sched_releasetcb(tcb);
errout:
errno = ENOMEM;
return ERROR;
}
/****************************************************************************
* Public 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. The errno will be set to
* indicate the nature of the error (always ENOMEM).
*
****************************************************************************/
#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
{
#ifndef CONFIG_CUSTOM_STACK
return thread_create(name, TCB_FLAG_TTYPE_TASK, priority, stack_size, entry, argv);
#else
return thread_create(name, TCB_FLAG_TTYPE_TASK, priority, entry, argv);
#endif
}
/****************************************************************************
* Name: kernel_thread
*
* Description:
* This function creates and activates a kernel thread task with kernel-
* mode privileges. It is identical to task_create() except that it
* configures the newly started thread to run in kernel model.
*
* Input Parameters:
* (same as task_create())
*
* Return Value:
* (same as task_create())
*
****************************************************************************/
#ifndef CONFIG_CUSTOM_STACK
int kernel_thread(const char *name, int priority,
int stack_size, main_t entry, const char *argv[])
#else
int kernel_thread(const char *name, int priority,
main_t entry, const char *argv[])
#endif
{
#ifndef CONFIG_CUSTOM_STACK
return thread_create(name, TCB_FLAG_TTYPE_KERNEL, priority, stack_size, entry, argv);
#else
return thread_create(name, TCB_FLAG_TTYPE_KERNEL, priority, entry, argv);
#endif
}