d7f02a8cb6
Since pthread_mutex is implemented by sem, it is impossible to see in ps who holds the lock and causes the wait. Replace sem with mutex implementation to solve the above problems Signed-off-by: yinshengkai <yinshengkai@xiaomi.com>
131 lines
3.4 KiB
C
131 lines
3.4 KiB
C
/****************************************************************************
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* sched/pthread/pthread_condwait.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 <unistd.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 <nuttx/cancelpt.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: int pthread_cond_wait
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*
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* Description:
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* A thread can wait for a condition variable to be signalled or broadcast.
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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_wait(FAR pthread_cond_t *cond, FAR pthread_mutex_t *mutex)
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{
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int status;
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int ret;
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irqstate_t flags;
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sinfo("cond=%p mutex=%p\n", cond, mutex);
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/* pthread_cond_wait() is a cancellation point */
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enter_cancellation_point();
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/* Make sure that non-NULL references were provided. */
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if (cond == NULL || mutex == NULL)
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{
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ret = EINVAL;
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}
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/* Make sure that the caller holds the mutex */
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else if (!mutex_is_hold(&mutex->mutex))
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{
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ret = EPERM;
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}
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else
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{
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unsigned int nlocks;
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/* Give up the mutex */
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sinfo("Give up mutex / take cond\n");
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flags = enter_critical_section();
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sched_lock();
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ret = pthread_mutex_breaklock(mutex, &nlocks);
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/* Take the semaphore. This may be awakened only be a signal (EINTR)
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* or if the thread is canceled (ECANCELED)
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*/
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status = pthread_sem_take(&cond->sem, NULL);
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if (ret == OK)
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{
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/* Report the first failure that occurs */
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ret = status;
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}
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sched_unlock();
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leave_critical_section(flags);
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/* Reacquire the mutex.
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*
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* When cancellation points are enabled, we need to hold the mutex
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* when the pthread is canceled and cleanup handlers, if any, are
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* entered.
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*/
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sinfo("Reacquire mutex...\n");
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status = pthread_mutex_restorelock(mutex, nlocks);
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if (ret == OK)
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{
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/* Report the first failure that occurs */
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ret = status;
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}
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}
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leave_cancellation_point();
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sinfo("Returning %d\n", ret);
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return ret;
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}
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