3d0320f891
from https://pubs.opengroup.org/onlinepubs/007904875/functions/setpriority.html: 1.The nice value shall in the range [-{NZERO},{NZERO} -1] 2.Lower nice value shall cause more favorable scheduling Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com> Change-Id: I5ad60d92abc3b69fbaa406da68cec2e40ca3fa6d
76 lines
2.4 KiB
C
76 lines
2.4 KiB
C
/****************************************************************************
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* libs/libc/unistd/lib_setpriority.c
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*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership. The
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* ASF licenses this file to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance with the
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* License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <sched.h>
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#include <errno.h>
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#include <unistd.h>
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: setpriority
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*
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* Description:
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* The setpriority() function shall set the nice value of a process,
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* process group, or user to value+ {NZERO}.
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*
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* Input Parameters:
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* which - PRIO_PROCESS, PRIO_PGRP, or PRIO_USER, ignored in current
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* implementation.
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* who - Process id is interpreted relative to "which"
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* value - Value in the range SCHED_PRIORITY_MIN to SCHED_PRIORITY_MAX
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*
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* Returned Value:
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* Upon successful completion, setpriority() shall return 0; otherwise,
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* -1 shall be returned and errno set to indicate the error.
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*
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* Assumptions:
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*
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****************************************************************************/
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int setpriority(int which, id_t who, int value)
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{
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struct sched_param param;
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int ret;
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if (who == 0)
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{
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who = getpid();
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}
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ret = sched_getparam(who, ¶m);
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if (ret < 0)
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{
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return ret;
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}
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param.sched_priority = NZERO - value;
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return sched_setparam(who, ¶m);
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}
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