incubator-nuttx/sched/task/task_start.c

145 lines
4.4 KiB
C

/****************************************************************************
* sched/task/task_start.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 <stdlib.h>
#include <sched.h>
#include <assert.h>
#include <debug.h>
#include <string.h>
#include <nuttx/arch.h>
#include <nuttx/sched.h>
#include "group/group.h"
#include "sched/sched.h"
#include "signal/signal.h"
#include "task/task.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* This is an artificial limit to detect error conditions where an argv[]
* list is not properly terminated.
*/
#define MAX_START_ARGS 256
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: nxtask_start
*
* Description:
* This function is the low level entry point into the main thread of
* execution of a task. It receives initial control when the task is
* started and calls main entry point of the newly started task.
*
* Input Parameters:
* None
*
* Returned Value:
* None
*
****************************************************************************/
void nxtask_start(void)
{
FAR struct task_tcb_s *tcb = (FAR struct task_tcb_s *)this_task();
int exitcode = EXIT_FAILURE;
int argc;
DEBUGASSERT((tcb->cmn.flags & TCB_FLAG_TTYPE_MASK) != \
TCB_FLAG_TTYPE_PTHREAD);
#ifdef CONFIG_SIG_DEFAULT
if ((tcb->cmn.flags & TCB_FLAG_TTYPE_MASK) != TCB_FLAG_TTYPE_KERNEL)
{
/* Set up default signal actions for NON-kernel thread */
nxsig_default_initialize(&tcb->cmn);
}
#endif
/* Execute the start hook if one has been registered */
#ifdef CONFIG_SCHED_STARTHOOK
if (tcb->starthook != NULL)
{
tcb->starthook(tcb->starthookarg);
}
#endif
/* Count how many non-null arguments we are passing. The first non-null
* argument terminates the list .
*/
argc = 1;
while (tcb->cmn.group->tg_info->argv[argc])
{
/* Increment the number of args. Here is a sanity check to
* prevent running away with an unterminated argv[] list.
* MAX_START_ARGS should be sufficiently large that this never
* happens in normal usage.
*/
if (++argc > MAX_START_ARGS)
{
exit(EXIT_FAILURE);
}
}
/* Call the 'main' entry point passing argc and argv. In the kernel build
* this has to be handled differently if we are starting a user-space task;
* we have to switch to user-mode before calling the task.
*/
if ((tcb->cmn.flags & TCB_FLAG_TTYPE_MASK) == TCB_FLAG_TTYPE_KERNEL)
{
exitcode = tcb->cmn.entry.main(argc, tcb->cmn.group->tg_info->argv);
}
else
{
#ifdef CONFIG_BUILD_FLAT
nxtask_startup(tcb->cmn.entry.main, argc,
tcb->cmn.group->tg_info->argv);
#else
up_task_start(tcb->cmn.entry.main, argc,
tcb->cmn.group->tg_info->argv);
#endif
}
/* Call exit() if/when the task returns */
exit(exitcode);
}