nuttx/libs/libc/pthread/pthread_rwlockattr_setpshared.c

100 lines
3.8 KiB
C

/********************************************************************************
* libs/libc/pthread/pthread_rwlockattr_setpshared.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 <pthread.h>
#include <errno.h>
#include <debug.h>
/********************************************************************************
* Pre-processor Definitions
********************************************************************************/
/********************************************************************************
* Private Type Declarations
********************************************************************************/
/********************************************************************************
* Public Data
********************************************************************************/
/********************************************************************************
* Private Data
********************************************************************************/
/********************************************************************************
* Private Function Prototypes
********************************************************************************/
/********************************************************************************
* Public Functions
********************************************************************************/
/********************************************************************************
* Name: pthread_rwlockattr_setpshared
*
* Description:
* The process-shared attribute is set to PTHREAD_PROCESS_SHARED to permit
* a rwlock to be operated upon by any thread that has access to the
* memory where the rwlock is allocated. If the process-shared attribute
* is PTHREAD_PROCESS_PRIVATE, the rwlock can only be operated upon by
* threads created within the same process as the thread that initialized
* the rwlock.
* If threads of different processes attempt to operate on such a rwlock,
* the behavior is undefined. The default value of the attribute is
* PTHREAD_PROCESS_PRIVATE.
*
* Both constants PTHREAD_PROCESS_SHARED and PTHREAD_PROCESS_PRIVATE are
* defined in pthread.h.
*
* Input Parameters:
* attr - rwlock attributes to be modified.
* pshared - the new value of the pshared attribute.
*
* Returned Value:
* 0 (OK) on success or EINVAL if either attr is invalid or pshared is not
* one of PTHREAD_PROCESS_SHARED or PTHREAD_PROCESS_PRIVATE.
*
* Assumptions:
*
********************************************************************************/
int pthread_rwlockattr_setpshared(FAR pthread_rwlockattr_t *attr, int pshared)
{
int ret = OK;
if (!attr || (pshared != PTHREAD_PROCESS_SHARED &&
pshared != PTHREAD_PROCESS_PRIVATE))
{
ret = EINVAL;
}
else
{
attr->pshared = pshared;
}
return ret;
}