nuttx/sched/pthread/pthread_create.c
chao an cd169e9b2c sched/pthread: simplify pthread_create() branch logic
remove redundant branch logic

Signed-off-by: chao an <anchao@lixiang.com>
2024-06-07 01:32:42 +08:00

469 lines
13 KiB
C

/****************************************************************************
* sched/pthread/pthread_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 <stdbool.h>
#include <string.h>
#include <pthread.h>
#include <sched.h>
#include <debug.h>
#include <assert.h>
#include <errno.h>
#include <nuttx/queue.h>
#include <nuttx/sched.h>
#include <nuttx/arch.h>
#include <nuttx/semaphore.h>
#include <nuttx/kmalloc.h>
#include <nuttx/pthread.h>
#include "task/task.h"
#include "sched/sched.h"
#include "group/group.h"
#include "clock/clock.h"
#include "pthread/pthread.h"
#include "tls/tls.h"
/****************************************************************************
* Public Data
****************************************************************************/
/* Default pthread attributes (see include/nuttx/pthread.h). When configured
* to build separate kernel- and user-address spaces, this global is
* duplicated in each address spaced. This copy can only be shared within
* the kernel address space.
*/
const pthread_attr_t g_default_pthread_attr = PTHREAD_ATTR_INITIALIZER;
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: pthread_tcb_setup
*
* Description:
* This function sets up parameters in the Task Control Block (TCB) in
* preparation for starting a new thread.
*
* pthread_tcb_setup() is called from nxtask_init() and nxtask_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
* trampoline - User space pthread startup function
* arg - The argument to provide to the pthread on startup.
*
* Returned Value:
* None
*
****************************************************************************/
static inline void pthread_tcb_setup(FAR struct pthread_tcb_s *ptcb,
FAR struct tcb_s *parent,
pthread_trampoline_t trampoline,
pthread_addr_t arg)
{
#if CONFIG_TASK_NAME_SIZE > 0
/* Copy the pthread name into the TCB */
strlcpy(ptcb->cmn.name, parent->name, 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.
*/
ptcb->trampoline = trampoline;
ptcb->arg = arg;
}
/****************************************************************************
* Name: pthread_start
*
* Description:
* This function is the low level entry point into the pthread
*
* Input Parameters:
* None
*
****************************************************************************/
static void pthread_start(void)
{
FAR struct pthread_tcb_s *ptcb = (FAR struct pthread_tcb_s *)this_task();
/* The priority of this thread may have been boosted to avoid priority
* inversion problems. If that is the case, then drop to the correct
* execution priority.
*/
if (ptcb->cmn.sched_priority > ptcb->cmn.init_priority)
{
DEBUGVERIFY(nxsched_set_priority(&ptcb->cmn, ptcb->cmn.init_priority));
}
/* 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.
*/
DEBUGASSERT(ptcb->trampoline != NULL && ptcb->cmn.entry.pthread != NULL);
#ifdef CONFIG_BUILD_FLAT
ptcb->trampoline(ptcb->cmn.entry.pthread, ptcb->arg);
#else
up_pthread_start(ptcb->trampoline, ptcb->cmn.entry.pthread, ptcb->arg);
#endif
/* The thread has returned (should never happen) */
DEBUGPANIC();
pthread_exit(NULL);
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: nx_pthread_create
*
* Description:
* This function creates and activates a new thread with specified
* attributes.
*
* Input Parameters:
* trampoline - The user space startup function
* thread - The pthread handle to be used
* attr - It points to a pthread_attr_t structure whose contents are
* used at thread creation time to determine attributes
* for the new thread
* entry - The new thread starts execution by invoking entry
* arg - It is passed as the sole argument of entry
*
* Returned Value:
* OK (0) on success; a (non-negated) errno value on failure. The errno
* variable is not set.
*
****************************************************************************/
int nx_pthread_create(pthread_trampoline_t trampoline, FAR pthread_t *thread,
FAR const pthread_attr_t *attr,
pthread_startroutine_t entry, pthread_addr_t arg)
{
pthread_attr_t default_attr = g_default_pthread_attr;
FAR struct pthread_tcb_s *ptcb;
struct sched_param param;
FAR struct tcb_s *parent;
int policy;
int errcode;
int ret;
DEBUGASSERT(trampoline != NULL);
parent = this_task();
DEBUGASSERT(parent != NULL);
/* If attributes were not supplied, use the default attributes */
if (!attr)
{
/* Inherit parent priority by default. except idle */
if (!is_idle_task(parent))
{
default_attr.priority = parent->sched_priority;
}
attr = &default_attr;
}
/* Allocate a TCB for the new task. */
ptcb = kmm_zalloc(sizeof(struct pthread_tcb_s));
if (!ptcb)
{
serr("ERROR: Failed to allocate TCB\n");
return ENOMEM;
}
ptcb->cmn.flags |= TCB_FLAG_FREE_TCB;
/* Initialize the task join */
nxtask_joininit(&ptcb->cmn);
/* Bind the parent's group to the new TCB (we have not yet joined the
* group).
*/
group_bind(ptcb);
#ifdef CONFIG_ARCH_ADDRENV
/* Share the address environment of the parent task group. */
ret = addrenv_join(this_task(), (FAR struct tcb_s *)ptcb);
if (ret < 0)
{
errcode = -ret;
goto errout_with_tcb;
}
#endif
if (attr->detachstate == PTHREAD_CREATE_DETACHED)
{
ptcb->cmn.flags |= TCB_FLAG_DETACHED;
}
if (attr->stackaddr)
{
/* Use pre-allocated stack */
ret = up_use_stack((FAR struct tcb_s *)ptcb, attr->stackaddr,
attr->stacksize);
}
else
{
/* 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_tcb;
}
#if defined(CONFIG_ARCH_ADDRENV) && \
defined(CONFIG_BUILD_KERNEL) && defined(CONFIG_ARCH_KERNEL_STACK)
/* Allocate the kernel stack */
ret = up_addrenv_kstackalloc(&ptcb->cmn);
if (ret < 0)
{
errcode = ENOMEM;
goto errout_with_tcb;
}
#endif
/* Initialize thread local storage */
ret = tls_init_info(&ptcb->cmn);
if (ret != OK)
{
errcode = -ret;
goto errout_with_tcb;
}
/* 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)
{
/* Get the priority (and any other scheduling parameters) for this
* thread.
*/
ret = nxsched_get_param(0, &param);
if (ret < 0)
{
errcode = -ret;
goto errout_with_tcb;
}
/* Get the scheduler policy for this thread */
policy = nxsched_get_scheduler(0);
if (policy < 0)
{
errcode = -policy;
goto errout_with_tcb;
}
}
else
{
/* Use the scheduler policy and policy the attributes */
policy = attr->policy;
param.sched_priority = attr->priority;
#ifdef CONFIG_SCHED_SPORADIC
param.sched_ss_low_priority = attr->low_priority;
param.sched_ss_max_repl = attr->max_repl;
param.sched_ss_repl_period.tv_sec = attr->repl_period.tv_sec;
param.sched_ss_repl_period.tv_nsec = attr->repl_period.tv_nsec;
param.sched_ss_init_budget.tv_sec = attr->budget.tv_sec;
param.sched_ss_init_budget.tv_nsec = attr->budget.tv_nsec;
#endif
}
#ifdef CONFIG_SCHED_SPORADIC
if (policy == SCHED_SPORADIC)
{
FAR struct sporadic_s *sporadic;
sclock_t repl_ticks;
sclock_t budget_ticks;
/* Convert timespec values to system clock ticks */
clock_time2ticks(&param.sched_ss_repl_period, &repl_ticks);
clock_time2ticks(&param.sched_ss_init_budget, &budget_ticks);
/* The replenishment period must be greater than or equal to the
* budget period.
*/
if (repl_ticks < budget_ticks)
{
errcode = EINVAL;
goto errout_with_tcb;
}
/* Initialize the sporadic policy */
ret = nxsched_initialize_sporadic(&ptcb->cmn);
if (ret >= 0)
{
sporadic = ptcb->cmn.sporadic;
DEBUGASSERT(sporadic != NULL);
/* Save the sporadic scheduling parameters */
sporadic->hi_priority = param.sched_priority;
sporadic->low_priority = param.sched_ss_low_priority;
sporadic->max_repl = param.sched_ss_max_repl;
sporadic->repl_period = repl_ticks;
sporadic->budget = budget_ticks;
/* And start the first replenishment interval */
ret = nxsched_start_sporadic(&ptcb->cmn);
}
/* Handle any failures */
if (ret < 0)
{
errcode = -ret;
goto errout_with_tcb;
}
}
#endif
/* Initialize the task control block */
ret = pthread_setup_scheduler(ptcb, param.sched_priority, pthread_start,
entry);
if (ret != OK)
{
errcode = EBUSY;
goto errout_with_tcb;
}
#ifdef CONFIG_SMP
/* pthread_setup_scheduler() will set the affinity mask by inheriting the
* setting from the parent task. We need to override this setting
* with the value from the pthread attributes unless that value is
* zero: Zero is the default value and simply means to inherit the
* parent thread's affinity mask.
*/
if (attr->affinity != 0)
{
ptcb->cmn.affinity = attr->affinity;
}
#endif
/* Configure the TCB for a pthread receiving on parameter
* passed by value
*/
pthread_tcb_setup(ptcb, parent, trampoline, arg);
/* Join the parent's task group */
group_join(ptcb);
/* Set the appropriate scheduling policy in the TCB */
ptcb->cmn.flags &= ~TCB_FLAG_POLICY_MASK;
switch (policy)
{
default:
case SCHED_FIFO:
ptcb->cmn.flags |= TCB_FLAG_SCHED_FIFO;
break;
#if CONFIG_RR_INTERVAL > 0
case SCHED_OTHER:
case SCHED_RR:
ptcb->cmn.flags |= TCB_FLAG_SCHED_RR;
ptcb->cmn.timeslice = MSEC2TICK(CONFIG_RR_INTERVAL);
break;
#endif
#ifdef CONFIG_SCHED_SPORADIC
case SCHED_SPORADIC:
ptcb->cmn.flags |= TCB_FLAG_SCHED_SPORADIC;
break;
#endif
}
/* Then activate the task */
sched_lock();
nxtask_activate((FAR struct tcb_s *)ptcb);
/* Return the thread information to the caller */
if (thread != NULL)
{
*thread = (pthread_t)ptcb->cmn.pid;
}
sched_unlock();
return OK;
errout_with_tcb:
/* Since we do not join the group, assign group to NULL to clear binding */
ptcb->cmn.group = NULL;
nxsched_release_tcb((FAR struct tcb_s *)ptcb, TCB_FLAG_TTYPE_PTHREAD);
return errcode;
}