111 lines
3.1 KiB
C
111 lines
3.1 KiB
C
/****************************************************************************
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* sched/pthread/pthread_condbroadcast.c
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*
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* SPDX-License-Identifier: Apache-2.0
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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 <sched.h>
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#include <errno.h>
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#include <debug.h>
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#include "pthread/pthread.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_cond_broadcast
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*
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* Description:
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* A thread broadcast on a condition variable.
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*
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* Input Parameters:
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* None
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*
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* Returned Value:
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* None
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*
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* Assumptions:
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*
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****************************************************************************/
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int pthread_cond_broadcast(FAR pthread_cond_t *cond)
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{
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int ret = OK;
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int sval;
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sinfo("cond=%p\n", cond);
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if (!cond)
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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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/* Disable pre-emption until all of the waiting threads have been
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* restarted. This is necessary to assure that the sval behaves as
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* expected in the following while loop
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*/
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sched_lock();
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/* Get the current value of the semaphore */
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if (nxsem_get_value(&cond->sem, &sval) != OK)
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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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/* Loop until all of the waiting threads have been restarted. */
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while (sval < 0)
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{
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/* If the value is less than zero (meaning that one or more
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* thread is waiting), then post the condition semaphore.
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* Only the highest priority waiting thread will get to execute
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*/
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ret = -nxsem_post(&cond->sem);
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/* Increment the semaphore count (as was done by the
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* above post).
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*/
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sval++;
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}
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}
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/* Now we can let the restarted threads run */
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sched_unlock();
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}
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sinfo("Returning %d\n", ret);
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return ret;
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}
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