incubator-nuttx/sched/pthread/pthread_setaffinity.c

106 lines
3.9 KiB
C

/****************************************************************************
* sched/pthread/pthread_setaffinity.c
*
* Copyright (C) 2016 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <pthread.h>
#include <sched.h>
#include <errno.h>
#include <debug.h>
#include "pthread/pthread.h"
#ifdef CONFIG_SMP
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: pthread_setaffinity
*
* Description:
* The pthread_setaffinity_np() function sets the CPU affinity mask of
* the thread thread to the CPU set pointed to by cpuset. If the call
* is successful, and the thread is not currently running on one of the
* CPUs in cpuset, then it is migrated to one of those CPUs.
* The argument cpusetsize is the length (in bytes) of the buffer
* pointed to by cpuset. Typically, this argument would be specified as
* sizeof(cpu_set_t).
*
* Parameters:
* thread - The ID of thread whose affinity set will be modified.
* cpusetsize - Size of cpuset. MUST be sizeofcpu_set_t().
* cpuset - Provides the new affinity set for the thread.
*
* Return Value:
* 0 if successful. Otherwise, an errno value is returned indicating the
* nature of the failure.
*
****************************************************************************/
int pthread_setaffinity_np(pthread_t thread, size_t cpusetsize,
FAR const cpu_set_t *cpuset)
{
int ret;
sdbg("thread ID=%d cpusetsize=%d cpuset=%p\n",
(int)thread, (int)cpusetsize, cpusetsize);
DEBUGASSERT(thread > 0 && cpusetsize == sizeof(cpu_set_t) &&
cpuset != NULL);
/* Let sched_setaffinity do all of the work */
ret = sched_setaffinity((pid_t)thread, cpusetsize, cpuset);
if (ret < 0)
{
/* If sched_setaffinity() fails, return the errno */
ret = get_errno();
DEBUGASSERT(ret > 0);
}
return ret;
}
#endif /* CONFIG_SMP */