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nuttx-bb/nuttx/sched/pthread_create.c

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/****************************************************************************
* sched/pthread_create.c
*
* Copyright (C) 2007-2009, 2011, 2013 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 <stdbool.h>
#include <string.h>
#include <pthread.h>
#include <sched.h>
#include <debug.h>
#include <errno.h>
#include <queue.h>
#include <nuttx/kmalloc.h>
#include <nuttx/pthread.h>
#include <nuttx/arch.h>
#include "os_internal.h"
#include "group_internal.h"
#include "clock_internal.h"
#include "pthread_internal.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Private Type Declarations
****************************************************************************/
/****************************************************************************
* Global Variables
****************************************************************************/
/* Default pthread attributes */
pthread_attr_t g_default_pthread_attr = PTHREAD_ATTR_INITIALIZER;
/****************************************************************************
* Private Variables
****************************************************************************/
/* This is the name for name-less pthreads */
static const char g_pthreadname[] = "<pthread>";
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: pthread_argsetup
*
* Description:
* This functions sets up parameters in the Task Control Block (TCB) in
* preparation for starting a new thread.
*
* pthread_argsetup() is called from task_init() and task_start() to create
* a new task (with arguments cloned via strdup) or pthread_create() which
* has one argument passed by value (distinguished by the pthread boolean
* argument).
*
* Input Parameters:
* tcb - Address of the new task's TCB
* arg - The argument to provide to the pthread on startup.
*
* Return Value:
* None
*
****************************************************************************/
static inline void pthread_argsetup(FAR struct pthread_tcb_s *tcb, pthread_addr_t arg)
{
#if CONFIG_TASK_NAME_SIZE > 0
/* Copy the pthread name into the TCB */
strncpy(tcb->cmn.name, g_pthreadname, CONFIG_TASK_NAME_SIZE);
#endif /* CONFIG_TASK_NAME_SIZE */
/* For pthreads, args are strictly pass-by-value; that actual
* type wrapped by pthread_addr_t is unknown.
*/
tcb->arg = arg;
}
/****************************************************************************
* Name: pthread_addjoininfo
*
* Description:
* Add a join structure to the local data set.
*
* Parameters:
* pjoin
*
* Return Value:
* None
*
* Assumptions:
* The caller has provided protection from re-entrancy.
*
****************************************************************************/
static inline void pthread_addjoininfo(FAR struct task_group_s *group,
FAR struct join_s *pjoin)
{
pjoin->next = NULL;
if (!group->tg_jointail)
{
group->tg_joinhead = pjoin;
}
else
{
group->tg_jointail->next = pjoin;
}
group->tg_jointail = pjoin;
}
/****************************************************************************
* Name: pthread_start
*
* Description:
* This function is the low level entry point into the pthread
*
* Parameters:
* None
*
****************************************************************************/
static void pthread_start(void)
{
FAR struct pthread_tcb_s *ptcb = (FAR struct pthread_tcb_s*)g_readytorun.head;
FAR struct task_group_s *group = ptcb->cmn.group;
FAR struct join_s *pjoin = (FAR struct join_s*)ptcb->joininfo;
pthread_addr_t exit_status;
DEBUGASSERT(group && pjoin);
/* Sucessfully spawned, add the pjoin to our data set. */
(void)pthread_takesemaphore(&group->tg_joinsem);
pthread_addjoininfo(group, pjoin);
(void)pthread_givesemaphore(&group->tg_joinsem);
/* Report to the spawner that we successfully started. */
pjoin->started = true;
(void)pthread_givesemaphore(&pjoin->data_sem);
/* Pass control to the thread entry point. In the kernel build this has to
* be handled differently if we are starting a user-space pthread; we have
* to switch to user-mode before calling into the pthread.
*/
#ifdef CONFIG_NUTTX_KERNEL
up_pthread_start(ptcb->cmn.entry.pthread, ptcb->arg);
exit_status = NULL;
#else
exit_status = (*ptcb->cmn.entry.pthread)(ptcb->arg);
#endif
/* The thread has returned (should never happen in the kernel mode case) */
pthread_exit(exit_status);
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: pthread_create
*
* Description:
* This function creates and activates a new thread with a specified
* attributes.
*
* Input Parameters:
* thread
* attr
* start_routine
* arg
*
* Returned value:
* OK (0) on success; a (non-negated) errno value on failure. The errno
* variable is not set.
*
****************************************************************************/
int pthread_create(FAR pthread_t *thread, FAR pthread_attr_t *attr,
pthread_startroutine_t start_routine, pthread_addr_t arg)
{
FAR struct pthread_tcb_s *ptcb;
FAR struct join_s *pjoin;
int priority;
#if CONFIG_RR_INTERVAL > 0
int policy;
#endif
int errcode;
pid_t pid;
int ret;
/* If attributes were not supplied, use the default attributes */
if (!attr)
{
attr = &g_default_pthread_attr;
}
/* Allocate a TCB for the new task. */
ptcb = (FAR struct pthread_tcb_s *)kzalloc(sizeof(struct pthread_tcb_s));
if (!ptcb)
{
sdbg("ERROR: Failed to allocate TCB\n");
return ENOMEM;
}
/* Bind the parent's group to the new TCB (we have not yet joined the
* group).
*/
#ifdef HAVE_TASK_GROUP
ret = group_bind(ptcb);
if (ret < 0)
{
errcode = ENOMEM;
goto errout_with_tcb;
}
#endif
/* Share the address environment of the parent task. NOTE: Only tasks
* created throught the nuttx/binfmt loaders may have an address
* environment.
*/
#ifdef CONFIG_ADDRENV
ret = up_addrenv_share((FAR const struct tcb_s *)g_readytorun.head,
(FAR struct tcb_s *)ptcb);
if (ret < 0)
{
errcode = -ret;
goto errout_with_tcb;
}
#endif
/* Allocate a detachable structure to support pthread_join logic */
pjoin = (FAR struct join_s*)kzalloc(sizeof(struct join_s));
if (!pjoin)
{
sdbg("ERROR: Failed to allocate join\n");
errcode = ENOMEM;
goto errout_with_tcb;
}
/* Allocate the stack for the TCB */
ret = up_create_stack((FAR struct tcb_s *)ptcb, attr->stacksize,
TCB_FLAG_TTYPE_PTHREAD);
if (ret != OK)
{
errcode = ENOMEM;
goto errout_with_join;
}
/* Should we use the priority and scheduler specified in the
* pthread attributes? Or should we use the current thread's
* priority and scheduler?
*/
if (attr->inheritsched == PTHREAD_INHERIT_SCHED)
{
struct sched_param param;
/* Get the priority for this thread. */
ret = sched_getparam(0, &param);
if (ret == OK)
{
priority = param.sched_priority;
}
else
{
priority = SCHED_FIFO;
}
/* Get the scheduler policy for this thread */
#if CONFIG_RR_INTERVAL > 0
policy = sched_getscheduler(0);
if (policy == ERROR)
{
policy = SCHED_FIFO;
}
#endif
}
else
{
/* Use the priority and scheduler from the attributes */
priority = attr->priority;
#if CONFIG_RR_INTERVAL > 0
policy = attr->policy;
#endif
}
/* Initialize the task control block */
ret = pthread_schedsetup(ptcb, priority, pthread_start, start_routine);
if (ret != OK)
{
errcode = EBUSY;
goto errout_with_join;
}
/* Configure the TCB for a pthread receiving on parameter
* passed by value
*/
pthread_argsetup(ptcb, arg);
/* Join the parent's task group */
#ifdef HAVE_TASK_GROUP
ret = group_join(ptcb);
if (ret < 0)
{
errcode = ENOMEM;
goto errout_with_join;
}
#endif
/* Attach the join info to the TCB. */
ptcb->joininfo = (FAR void *)pjoin;
/* If round robin scheduling is selected, set the appropriate flag
* in the TCB.
*/
#if CONFIG_RR_INTERVAL > 0
if (policy == SCHED_RR)
{
ptcb->cmn.flags |= TCB_FLAG_ROUND_ROBIN;
ptcb->cmn.timeslice = CONFIG_RR_INTERVAL / MSEC_PER_TICK;
}
#endif
/* Get the assigned pid before we start the task (who knows what
* could happen to ptcb after this!). Copy this ID into the join structure
* as well.
*/
pid = (int)ptcb->cmn.pid;
pjoin->thread = (pthread_t)pid;
/* Initialize the semaphores in the join structure to zero. */
ret = sem_init(&pjoin->data_sem, 0, 0);
if (ret == OK)
{
ret = sem_init(&pjoin->exit_sem, 0, 0);
}
/* Activate the task */
sched_lock();
if (ret == OK)
{
ret = task_activate((FAR struct tcb_s *)ptcb);
}
if (ret == OK)
{
/* Wait for the task to actually get running and to register
* its join structure.
*/
(void)pthread_takesemaphore(&pjoin->data_sem);
/* Return the thread information to the caller */
if (thread)
{
*thread = (pthread_t)pid;
}
if (!pjoin->started)
{
ret = EINVAL;
}
sched_unlock();
(void)sem_destroy(&pjoin->data_sem);
}
else
{
sched_unlock();
dq_rem((FAR dq_entry_t*)ptcb, (dq_queue_t*)&g_inactivetasks);
(void)sem_destroy(&pjoin->data_sem);
(void)sem_destroy(&pjoin->exit_sem);
errcode = EIO;
goto errout_with_join;
}
return ret;
errout_with_join:
sched_kfree(pjoin);
ptcb->joininfo = NULL;
errout_with_tcb:
sched_releasetcb((FAR struct tcb_s *)ptcb, TCB_FLAG_TTYPE_PTHREAD);
return errcode;
}
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