incubator-nuttx/sched/pthread/pthread_setschedparam.c

108 lines
4.2 KiB
C

/****************************************************************************
* sched/pthread/pthread_setschedparam.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 <pthread.h>
#include <sched.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/sched.h>
#include "pthread/pthread.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: pthread_setschedparam
*
* Description:
* The pthread_setschedparam() functions will set 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_setschedparam() function will set the scheduling policy
* and associated scheduling parameters for the thread whose thread ID
* is given by 'thread' to the policy and associated parameters provided
* in 'policy' and 'param', respectively.
*
* 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.
*
* If the pthread_setschedparam() function fails, the scheduling parameters
* will not be changed for the target thread.
*
* Input Parameters:
* thread - The ID of thread whose scheduling parameters will be modified.
* policy - The new scheduling policy of the thread. Either SCHED_FIFO or
* SCHED_RR. SCHED_OTHER and SCHED_SPORADIC are not supported.
* param - Provides the new priority of the thread.
*
* Returned Value:
* 0 if successful. Otherwise, an error code identifying the cause of the
* failure:
*
* EINVAL The value specified by 'policy' or one of the scheduling
* parameters associated with the scheduling policy 'policy' is
* invalid.
* ENOTSUP An attempt was made to set the policy or scheduling parameters
* to an unsupported value (SCHED_OTHER and SCHED_SPORADIC in
* particular are not supported)
* EPERM The caller does not have the appropriate permission to set
* either the scheduling parameters or the scheduling policy of
* the specified thread. Or, the implementation does not allow
* the application to modify one of the parameters to the value
* specified.
* ESRCH The value specified by thread does not refer to a existing
* thread.
*
****************************************************************************/
int pthread_setschedparam(pthread_t thread, int policy,
FAR const struct sched_param *param)
{
int ret;
sinfo("thread ID=%d policy=%d param=%p\n", thread, policy, param);
/* Let nxsched_set_scheduler do all of the work */
ret = nxsched_set_scheduler((pid_t)thread, policy, param);
if (ret < 0)
{
/* If nxsched_set_scheduler() fails, return the positive errno value */
ret = -ret;
}
return ret;
}