9aa69168e4
barrier is used protect resources. don't lock Signed-off-by: anjiahao <anjiahao@xiaomi.com>
91 lines
3.5 KiB
C
91 lines
3.5 KiB
C
/****************************************************************************
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* libs/libc/pthread/pthread_barrierinit.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 <pthread.h>
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#include <semaphore.h>
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#include <errno.h>
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#include <debug.h>
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: pthread_barrier_init
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*
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* Description:
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* The pthread_barrier_init() function allocates any resources required to
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* use the barrier referenced by 'barrier' and initialized the barrier
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* with the attributes referenced by attr. If attr is NULL, the default
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* barrier attributes will be used. The results are undefined if
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* pthread_barrier_init() is called when any thread is blocked on the
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* barrier. The results are undefined if a barrier is used without first
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* being initialized. The results are undefined if pthread_barrier_init()
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* is called specifying an already initialized barrier.
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*
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* Input Parameters:
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* barrier - the barrier to be initialized
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* attr - barrier attributes to be used in the initialization.
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* count - the count to be associated with the barrier. The count
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* argument specifies the number of threads that must call
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* pthread_barrier_wait() before any of them successfully return from
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* the call. The value specified by count must be greater than zero.
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*
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* Returned Value:
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* 0 (OK) on success or on of the following error numbers:
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*
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* EAGAIN The system lacks the necessary resources to initialize another
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* barrier. EINVAL The barrier reference is invalid, or the values
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* specified by attr are invalid, or the value specified by count
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* is equal to zero.
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* ENOMEM Insufficient memory exists to initialize the barrier.
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* EBUSY The implementation has detected an attempt to reinitialize a
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* barrier while it is in use.
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*
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* Assumptions:
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*
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****************************************************************************/
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int pthread_barrier_init(FAR pthread_barrier_t *barrier,
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FAR const pthread_barrierattr_t *attr,
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unsigned int count)
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{
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int ret = OK;
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if (!barrier || count == 0)
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{
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ret = EINVAL;
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}
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else
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{
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sem_init(&barrier->sem, 0, 0);
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sem_setprotocol(&barrier->sem, SEM_PRIO_NONE);
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barrier->count = count;
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}
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return ret;
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}
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