nuttx/libs/libc/pthread/pthread_attr_setscope.c
2023-07-28 20:55:22 -07:00

81 lines
3.3 KiB
C

/****************************************************************************
* libs/libc/pthread/pthread_attr_setscope.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 <pthread.h>
#include <errno.h>
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: pthread_attr_setscope
*
* Description:
* The function sets the contention scope attribute of the thread
* attributes object referred to by attr to the value specified in scope.
* The contention scope attributes defines the set of threads against
* which a thread competes for resources such as the CPU.
*
* POSIX.1 specifies two possible values for scope:
* PTHREAD_SCOPE_SYSTEM:
* The thread competes for resources with all other threads in all
* processes on the system that are in the same scheduling allocation
* domain (a group of one or more processors).
* PTHREAD_SCOPE_SYSTEM threads are scheduled relative to one another
* according to their scheduling policy and priority.
*
* PTHREAD_SCOPE_PROCESS
* The thread competes for resources with all other threads in the
* same process that were also created with the PTHREAD_SCOPE_PROCESS
* contention scope. PTHREAD_SCOPE_PROCESS threads are scheduled relative
* to other threads in the process according to their scheduling policy
* and priority. POSIX.1 leaves it unspecified how these threads contend
* with other threads in other process on the system or with other
* threads in the same process that were created with the
* PTHREAD_SCOPE_SYSTEM contention scope.
*
* Input Parameters:
* attr - The pointer to pthread attr.
* scope - contention scope.
*
* Returned Value:
* On success, these functions return 0; on error, they return a nonzero
* error number.
*
****************************************************************************/
int pthread_attr_setscope(FAR pthread_attr_t *attr, int scope)
{
switch (scope)
{
case PTHREAD_SCOPE_SYSTEM:
return 0;
case PTHREAD_SCOPE_PROCESS:
return ENOTSUP;
default:
return EINVAL;
}
}