incubator-nuttx/sched/pthread/pthread_getschedparam.c

118 lines
4.0 KiB
C

/****************************************************************************
* sched/pthread/pthread_getschedparam.c
*
* SPDX-License-Identifier: Apache-2.0
*
* 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 <pthread.h>
#include <sched.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/sched.h>
#include "pthread/pthread.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: pthread_getschedparam
*
* Description:
* The pthread_getschedparam() functions will get the scheduling policy and
* parameters of threads. For SCHED_FIFO and SCHED_RR, the only required
* member of the sched_param structure is the priority sched_priority.
*
* The pthread_getschedparam() function will retrieve the scheduling
* policy and scheduling parameters for the thread whose thread ID is
* given by 'thread' and will store those values in 'policy' and 'param',
* respectively. The priority value returned from pthread_getschedparam()
* will be the value specified by the most recent pthread_setschedparam(),
* pthread_setschedprio(), or pthread_create() call affecting the target
* thread. It will not reflect any temporary adjustments to its priority
* (such as might result of any priority inheritance, for example).
*
* The policy parameter may have the value SCHED_FIFO, or SCHED_RR
* (SCHED_OTHER and SCHED_SPORADIC, in particular, are not supported).
* The SCHED_FIFO and SCHED_RR policies will have a single scheduling
* parameter, sched_priority.
*
* Input Parameters:
* thread - The ID of thread whose scheduling parameters will be queried.
* policy - The location to store the thread's scheduling policy.
* param - The location to store the thread's priority.
*
* Returned Value:
* 0 if successful. Otherwise, the error code ESRCH if the value specified
* by thread does not refer to an existing thread.
*
* Assumptions:
*
****************************************************************************/
int pthread_getschedparam(pthread_t thread, FAR int *policy,
FAR struct sched_param *param)
{
int ret;
sinfo("Thread ID=%d policy=%p param=%p\n", thread, policy, param);
if (policy == NULL || param == NULL)
{
ret = EINVAL;
}
else
{
/* Get the scheduler parameters of the thread. */
ret = nxsched_get_param((pid_t)thread, param);
if (ret < 0)
{
ret = -ret;
}
else
{
/* Get the scheduler policy. */
ret = nxsched_get_scheduler((pid_t)thread);
if (ret < 0)
{
ret = -ret;
}
else
{
*policy = ret;
ret = OK;
}
}
}
sinfo("Returning %d\n", ret);
return ret;
}