incubator-nuttx/sched/task/task_create.c

293 lines
9.9 KiB
C

/****************************************************************************
* sched/task/task_create.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* 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/sched.h>
#include <nuttx/kthread.h>
#include "sched/sched.h"
#include "group/group.h"
#include "task/task.h"
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: nxthread_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 kthread_create().
* 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. The array
* should be terminated with a NULL argv[] value. If no
* parameters are required, argv may be NULL.
*
* Returned Value:
* Returns the positive, non-zero process ID of the new task or a negated
* errno value to indicate the nature of any failure. If memory is
* insufficient or the task cannot be created -ENOMEM will be returned.
*
****************************************************************************/
static int nxthread_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 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");
return -ENOMEM;
}
/* Allocate a new task group with privileges appropriate for the parent
* thread type.
*/
ret = group_allocate(tcb, ttype);
if (ret < 0)
{
goto errout_with_tcb;
}
#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)
{
goto errout_with_tcb;
}
}
/* Allocate the stack for the TCB */
ret = up_create_stack((FAR struct tcb_s *)tcb, stack_size, ttype);
if (ret < OK)
{
goto errout_with_tcb;
}
/* Initialize the task control block */
ret = nxtask_schedsetup(tcb, priority, nxtask_start, entry, ttype);
if (ret < OK)
{
goto errout_with_tcb;
}
/* Setup to pass parameters to the new task */
nxtask_argsetup(tcb, name, argv);
/* Now we have enough in place that we can join the group */
ret = group_initialize(tcb);
if (ret < 0)
{
goto errout_with_tcb;
}
/* 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)
{
ret = -get_errno();
DEBUGASSERT(ret < 0);
/* The TCB was added to the active task list by nxtask_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);
return ret;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: nxtask_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.
*
* nxtask_create() is identical to the function task_create(), differing
* only in its return value: This function does not modify the errno
* variable. This is a non-standard, internal OS function and is not
* intended for use by application logic. Applications should use
* task_create().
*
* 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. The array
* should be terminated with a NULL argv[] value. If no
* parameters are required, argv may be NULL.
*
* Returned Value:
* Returns the positive, non-zero process ID of the new task or a negated
* errno value to indicate the nature of any failure. If memory is
* insufficient or the task cannot be created -ENOMEM will be returned.
*
****************************************************************************/
int nxtask_create(FAR const char *name, int priority,
int stack_size, main_t entry, FAR char * const argv[])
{
return nxthread_create(name, TCB_FLAG_TTYPE_TASK, priority, stack_size,
entry, argv);
}
/****************************************************************************
* 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. The array
* should be terminated with a NULL argv[] value. If no
* parameters are required, argv may be NULL.
*
* Returned 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 in
* the failure case to indicate the nature of the error.
*
****************************************************************************/
#ifndef CONFIG_BUILD_KERNEL
int task_create(FAR const char *name, int priority,
int stack_size, main_t entry, FAR char * const argv[])
{
int ret = nxtask_create(name, priority, stack_size, entry, argv);
if (ret < 0)
{
set_errno(-ret);
ret = ERROR;
}
return ret;
}
#endif
/****************************************************************************
* Name: kthread_create
*
* 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:
* 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. The array
* should be terminated with a NULL argv[] value. If no
* parameters are required, argv may be NULL.
*
* Returned Value:
* Returns the positive, non-zero process ID of the new task or a negated
* errno value to indicate the nature of any failure. If memory is
* insufficient or the task cannot be created -ENOMEM will be returned.
*
****************************************************************************/
int kthread_create(FAR const char *name, int priority,
int stack_size, main_t entry, FAR char *const argv[])
{
return nxthread_create(name, TCB_FLAG_TTYPE_KERNEL, priority, stack_size,
entry, argv);
}