nuttx/libs/libc/pthread/pthread_barrierinit.c
2021-03-09 23:18:28 +08:00

90 lines
3.5 KiB
C

/****************************************************************************
* libs/libc/pthread/pthread_barrierinit.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 <semaphore.h>
#include <errno.h>
#include <debug.h>
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: pthread_barrier_init
*
* Description:
* The pthread_barrier_init() function allocates any resources required to
* use the barrier referenced by 'barrier' and initialized the barrier
* with the attributes referenced by attr. If attr is NULL, the default
* barrier attributes will be used. The results are undefined if
* pthread_barrier_init() is called when any thread is blocked on the
* barrier. The results are undefined if a barrier is used without first
* being initialized. The results are undefined if pthread_barrier_init()
* is called specifying an already initialized barrier.
*
* Input Parameters:
* barrier - the barrier to be initialized
* attr - barrier attributes to be used in the initialization.
* count - the count to be associated with the barrier. The count
* argument specifies the number of threads that must call
* pthread_barrier_wait() before any of them successfully return from
* the call. The value specified by count must be greater than zero.
*
* Returned Value:
* 0 (OK) on success or on of the following error numbers:
*
* EAGAIN The system lacks the necessary resources to initialize another
* barrier. EINVAL The barrier reference is invalid, or the values
* specified by attr are invalid, or the value specified by count
* is equal to zero.
* ENOMEM Insufficient memory exists to initialize the barrier.
* EBUSY The implementation has detected an attempt to reinitialize a
* barrier while it is in use.
*
* Assumptions:
*
****************************************************************************/
int pthread_barrier_init(FAR pthread_barrier_t *barrier,
FAR const pthread_barrierattr_t *attr,
unsigned int count)
{
int ret = OK;
if (!barrier || count == 0)
{
ret = EINVAL;
}
else
{
sem_init(&barrier->sem, 0, 0);
barrier->count = count;
}
return ret;
}