incubator-nuttx/sched/task/task_create.c

267 lines
8.7 KiB
C

/****************************************************************************
* sched/task/task_create.c
*
* Copyright (C) 2007-2010, 2013-2014, 2016 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 <sys/types.h>
#include <sched.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/arch.h>
#include <nuttx/kmalloc.h>
#include <nuttx/kthread.h>
#include "sched/sched.h"
#include "group/group.h"
#include "task/task.h"
/****************************************************************************
* 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, common implementation of task_create() and kernel_thread().
* See comments with task_create() for further information.
*
* Input Parameters:
* name - Name of the new task
* ttype - 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).
*
****************************************************************************/
static int thread_create(FAR const char *name, uint8_t ttype, int priority,
int stack_size, main_t entry,
FAR char * const argv[])
{
FAR struct task_tcb_s *tcb;
pid_t pid;
int errcode;
int ret;
/* Allocate a TCB for the new task. */
tcb = (FAR struct task_tcb_s *)kmm_zalloc(sizeof(struct task_tcb_s));
if (!tcb)
{
serr("ERROR: Failed to allocate TCB\n");
errcode = ENOMEM;
goto errout;
}
/* Allocate a new task group with privileges appropriate for the parent
* thread type.
*/
#ifdef HAVE_TASK_GROUP
ret = group_allocate(tcb, ttype);
if (ret < 0)
{
errcode = -ret;
goto errout_with_tcb;
}
#endif
#if CONFIG_NFILE_DESCRIPTORS > 0 || CONFIG_NSOCKET_DESCRIPTORS > 0
#if 0 /* No... there are side effects */
/* Associate file descriptors with the new task. Exclude kernel threads;
* kernel threads do not have file or socket descriptors. They must use
* SYSLOG for output and the low-level psock interfaces for network I/O.
*/
if (ttype != TCB_FLAG_TTYPE_KERNEL)
#endif
{
ret = group_setuptaskfiles(tcb);
if (ret < OK)
{
errcode = -ret;
goto errout_with_tcb;
}
}
#endif
/* Allocate the stack for the TCB */
ret = up_create_stack((FAR struct tcb_s *)tcb, stack_size, ttype);
if (ret < OK)
{
errcode = -ret;
goto errout_with_tcb;
}
/* Initialize the task control block */
ret = task_schedsetup(tcb, priority, task_start, entry, ttype);
if (ret < OK)
{
errcode = -ret;
goto errout_with_tcb;
}
/* Setup to pass parameters to the new task */
(void)task_argsetup(tcb, name, argv);
/* Now we have enough in place that we can join the group */
#ifdef HAVE_TASK_GROUP
ret = group_initialize(tcb);
if (ret < 0)
{
errcode = -ret;
goto errout_with_tcb;
}
#endif
/* Get the assigned pid before we start the task */
pid = (int)tcb->cmn.pid;
/* Activate the task */
ret = task_activate((FAR struct tcb_s *)tcb);
if (ret < OK)
{
errcode = get_errno();
/* The TCB was added to the active task list by task_schedsetup() */
dq_rem((FAR dq_entry_t *)tcb, (FAR dq_queue_t *)&g_inactivetasks);
goto errout_with_tcb;
}
return pid;
errout_with_tcb:
sched_releasetcb((FAR struct tcb_s *)tcb, ttype);
errout:
set_errno(errcode);
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_BUILD_KERNEL
int task_create(FAR const char *name, int priority,
int stack_size, main_t entry, FAR char * const argv[])
{
return thread_create(name, TCB_FLAG_TTYPE_TASK, priority, stack_size,
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())
*
****************************************************************************/
int kernel_thread(FAR const char *name, int priority,
int stack_size, main_t entry, FAR char *const argv[])
{
return thread_create(name, TCB_FLAG_TTYPE_KERNEL, priority, stack_size,
entry, argv);
}