nuttx/sched/sched/sched_setscheduler.c
Gregory Nutt f92dba212d sched/sched/sched.h: Make naming of all internal names consistent:
1. Add internal scheduler functions should begin with nxsched_, not sched_
2. Follow the consistent naming patter of https://cwiki.apache.org/confluence/display/NUTTX/Naming+of+OS+Internal+Functions
2020-05-09 16:58:42 -03:00

325 lines
9.3 KiB
C

/****************************************************************************
* sched/sched/sched_setscheduler.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 <unistd.h>
#include <sched.h>
#include <assert.h>
#include <errno.h>
#include <nuttx/sched.h>
#include <nuttx/irq.h>
#include <nuttx/arch.h>
#include "sched/sched.h"
#include "clock/clock.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: nxsched_set_scheduler
*
* Description:
* nxsched_set_scheduler() sets both the scheduling policy and the priority
* for the task identified by pid. If pid equals zero, the scheduler of
* the calling task will be set. The parameter 'param' holds the priority
* of the thread under the new policy.
*
* nxsched_set_scheduler() is identical to the function sched_getparam(),
* 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 the standard
* sched_getparam().
*
* Input Parameters:
* pid - the task ID of the task to modify. If pid is zero, the calling
* task is modified.
* policy - Scheduling policy requested (either SCHED_FIFO or SCHED_RR)
* param - A structure whose member sched_priority is the new priority.
* The range of valid priority numbers is from SCHED_PRIORITY_MIN
* through SCHED_PRIORITY_MAX.
*
* Returned Value:
* On success, nxsched_set_scheduler() returns OK (zero). On error, a
* negated errno value is returned:
*
* EINVAL The scheduling policy is not one of the recognized policies.
* ESRCH The task whose ID is pid could not be found.
*
****************************************************************************/
int nxsched_set_scheduler(pid_t pid, int policy,
FAR const struct sched_param *param)
{
FAR struct tcb_s *tcb;
irqstate_t flags;
int ret;
/* Check for supported scheduling policy */
if (policy != SCHED_FIFO
#if CONFIG_RR_INTERVAL > 0
&& policy != SCHED_RR
#endif
#ifdef CONFIG_SCHED_SPORADIC
&& policy != SCHED_SPORADIC
#endif
)
{
return -EINVAL;
}
/* Check if the task to modify the calling task */
if (pid == 0)
{
pid = getpid();
}
/* Verify that the pid corresponds to a real task */
tcb = nxsched_get_tcb(pid);
if (!tcb)
{
return -ESRCH;
}
/* Prohibit any context switches while we muck with priority and scheduler
* settings.
*/
sched_lock();
/* Further, disable timer interrupts while we set up scheduling policy. */
flags = enter_critical_section();
tcb->flags &= ~TCB_FLAG_POLICY_MASK;
switch (policy)
{
default:
DEBUGPANIC();
break;
case SCHED_FIFO:
{
#ifdef CONFIG_SCHED_SPORADIC
/* Cancel any on-going sporadic scheduling */
if ((tcb->flags & TCB_FLAG_POLICY_MASK) == TCB_FLAG_SCHED_SPORADIC)
{
DEBUGVERIFY(nxsched_stop_sporadic(tcb));
}
#endif
/* Save the FIFO scheduling parameters */
tcb->flags |= TCB_FLAG_SCHED_FIFO;
#if CONFIG_RR_INTERVAL > 0 || defined(CONFIG_SCHED_SPORADIC)
tcb->timeslice = 0;
#endif
}
break;
#if CONFIG_RR_INTERVAL > 0
case SCHED_RR:
{
#ifdef CONFIG_SCHED_SPORADIC
/* Cancel any on-going sporadic scheduling */
if ((tcb->flags & TCB_FLAG_POLICY_MASK) == TCB_FLAG_SCHED_SPORADIC)
{
DEBUGVERIFY(nxsched_stop_sporadic(tcb));
}
#endif
/* Save the round robin scheduling parameters */
tcb->flags |= TCB_FLAG_SCHED_RR;
tcb->timeslice = MSEC2TICK(CONFIG_RR_INTERVAL);
}
break;
#endif
#ifdef CONFIG_SCHED_SPORADIC
case SCHED_SPORADIC:
{
FAR struct sporadic_s *sporadic;
sclock_t repl_ticks;
sclock_t budget_ticks;
if (param->sched_ss_max_repl < 1 ||
param->sched_ss_max_repl > CONFIG_SCHED_SPORADIC_MAXREPL)
{
ret = -EINVAL;
goto errout_with_irq;
}
/* 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);
/* Avoid zero/negative times */
if (repl_ticks < 1)
{
repl_ticks = 1;
}
if (budget_ticks < 1)
{
budget_ticks = 1;
}
/* The replenishment period must be greater than or equal to the
* budget period.
*/
#if 1
/* REVISIT: In the current implementation, the budget cannot
* exceed half the duty.
*/
if (repl_ticks < (2 * budget_ticks))
#else
if (repl_ticks < budget_ticks)
#endif
{
ret = -EINVAL;
goto errout_with_irq;
}
/* Initialize/reset current sporadic scheduling */
if ((tcb->flags & TCB_FLAG_POLICY_MASK) == TCB_FLAG_SCHED_SPORADIC)
{
ret = nxsched_reset_sporadic(tcb);
}
else
{
ret = nxsched_initialize_sporadic(tcb);
}
/* Save the sporadic scheduling parameters. */
if (ret >= 0)
{
tcb->flags |= TCB_FLAG_SCHED_SPORADIC;
tcb->timeslice = budget_ticks;
sporadic = tcb->sporadic;
DEBUGASSERT(sporadic != NULL);
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 restart at the next replenishment interval */
ret = nxsched_start_sporadic(tcb);
}
/* Handle errors */
if (ret < 0)
{
goto errout_with_irq;
}
}
break;
#endif
#if 0 /* Not supported */
case SCHED_OTHER:
tcb->flags |= TCB_FLAG_SCHED_OTHER;
break;
#endif
}
leave_critical_section(flags);
/* Set the new priority */
ret = nxsched_reprioritize(tcb, param->sched_priority);
sched_unlock();
return ret;
#ifdef CONFIG_SCHED_SPORADIC
errout_with_irq:
leave_critical_section(flags);
sched_unlock();
return ret;
#endif
}
/****************************************************************************
* Name: sched_setscheduler
*
* Description:
* sched_setscheduler() sets both the scheduling policy and the priority
* for the task identified by pid. If pid equals zero, the scheduler of
* the calling task will be set. The parameter 'param' holds the priority
* of the thread under the new policy.
*
* This function is a simply wrapper around nxsched_get_param() that
* sets the errno value in the event of an error.
*
* Input Parameters:
* pid - the task ID of the task to modify. If pid is zero, the calling
* task is modified.
* policy - Scheduling policy requested (either SCHED_FIFO or SCHED_RR)
* param - A structure whose member sched_priority is the new priority.
* The range of valid priority numbers is from SCHED_PRIORITY_MIN
* through SCHED_PRIORITY_MAX.
*
* Returned Value:
* On success, sched_setscheduler() returns OK (zero). On error, ERROR
* (-1) is returned, and errno is set appropriately:
*
* EINVAL The scheduling policy is not one of the recognized policies.
* ESRCH The task whose ID is pid could not be found.
*
****************************************************************************/
int sched_setscheduler(pid_t pid, int policy,
FAR const struct sched_param *param)
{
int ret = nxsched_set_scheduler(pid, policy, param);
if (ret < 0)
{
set_errno(-ret);
ret = ERROR;
}
return ret;
}