133 lines
4.1 KiB
C
133 lines
4.1 KiB
C
/****************************************************************************
|
|
* sched/sched/sched_getscheduler.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 <sched.h>
|
|
#include <errno.h>
|
|
|
|
#include <nuttx/sched.h>
|
|
#include <nuttx/arch.h>
|
|
|
|
#include "sched/sched.h"
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: nxsched_get_scheduler
|
|
*
|
|
* Description:
|
|
* sched_getscheduler() returns the scheduling policy currently
|
|
* applied to the task identified by pid. If pid equals zero, the
|
|
* policy of the calling task will be retrieved.
|
|
*
|
|
* This functions is identical to the function sched_getscheduler(),
|
|
* 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_getscheduler().
|
|
*
|
|
* Input Parameters:
|
|
* pid - the task ID of the task to query. If pid is zero, the
|
|
* calling task is queried.
|
|
*
|
|
* Returned Value:
|
|
* On success, sched_getscheduler() returns the policy for the task
|
|
* (either SCHED_FIFO or SCHED_RR). On error, a negated errno value
|
|
* returned:
|
|
*
|
|
* ESRCH The task whose ID is pid could not be found.
|
|
*
|
|
****************************************************************************/
|
|
|
|
int nxsched_get_scheduler(pid_t pid)
|
|
{
|
|
FAR struct tcb_s *tcb;
|
|
int policy;
|
|
|
|
/* Verify that the PID corresponds to a real task */
|
|
|
|
if (pid == 0)
|
|
{
|
|
tcb = this_task();
|
|
}
|
|
else
|
|
{
|
|
tcb = nxsched_get_tcb(pid);
|
|
}
|
|
|
|
if (tcb == NULL)
|
|
{
|
|
return -ESRCH;
|
|
}
|
|
|
|
/* Return the scheduling policy from the TCB. NOTE that the user-
|
|
* interpretable values are 1 based; the TCB values are zero-based.
|
|
*/
|
|
|
|
policy = (tcb->flags & TCB_FLAG_POLICY_MASK) >> TCB_FLAG_POLICY_SHIFT;
|
|
return policy + 1;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: sched_getscheduler
|
|
*
|
|
* Description:
|
|
* sched_getscheduler() returns the scheduling policy currently
|
|
* applied to the task identified by pid. If pid equals zero, the
|
|
* policy of the calling task will be retrieved.
|
|
*
|
|
* sched_getscheduler() is a simply wrapper around nxsched_get_scheduler()
|
|
* that sets the errno value in the event of an error.
|
|
*
|
|
* Input Parameters:
|
|
* pid - the task ID of the task to query. If pid is zero, the
|
|
* calling task is queried.
|
|
*
|
|
* Returned Value:
|
|
* On success, sched_getscheduler() returns the policy for the task
|
|
* (either SCHED_FIFO or SCHED_RR). On error, ERROR (-1) is
|
|
* returned, and errno is set appropriately:
|
|
*
|
|
* ESRCH The task whose ID is pid could not be found.
|
|
*
|
|
****************************************************************************/
|
|
|
|
int sched_getscheduler(pid_t pid)
|
|
{
|
|
int ret = nxsched_get_scheduler(pid);
|
|
if (ret < 0)
|
|
{
|
|
set_errno(-ret);
|
|
ret = ERROR;
|
|
}
|
|
|
|
return ret;
|
|
}
|