nuttx/sched/sched/sched_getcpu.c

66 lines
2.4 KiB
C

/****************************************************************************
* sched/sched/sched_getcpu.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 <sched.h>
#include <nuttx/arch.h>
#include "sched/sched.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: sched_getcpu
*
* Description:
* sched_getcpu() returns the number of the CPU on which the calling
* thread is currently executing.
*
* The return CPU number is guaranteed to be valid only at the time of
* the call. Unless the CPU affinity has been fixed using
* sched_setaffinity(), the OS might change the CPU at any time. The
* caller must allow for the possibility that the information returned is
* no longer current by the time the call returns.
*
* Non-Standard. Functionally equivalent to the GLIBC __GNU_SOURCE
* interface of the same name.
*
* Input Parameters:
* None
*
* Returned Value:
* A non-negative CPU number is returned on success. -1 (ERROR) is
* returned on failure with the errno value set to indicate the cause of
* the failure.
*
****************************************************************************/
int sched_getcpu(void)
{
return up_cpu_index(); /* Does not fail */
}