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5fa8634ce7
Restore the use of critical sections to provide mutual exclusion
between event wait and post operations. This allows replacing the
heavier semaphore-based mechanism with direct scheduler operations
for synchronization.
Signed-off-by: Chengdong Wang wangchengdong@lixiang.com
71 lines
2.4 KiB
C
71 lines
2.4 KiB
C
/****************************************************************************
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* sched/event/event_clear.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/sched.h>
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#include "event.h"
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: nxevent_clear
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*
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* Description:
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* Clear specific bits from the event mask of the given event object.
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*
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* Input Parameters:
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* event - Address of the event object
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* mask - Bit mask specifying which event flags should be cleared
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*
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* Returned Value:
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* Returns the previous event mask value of the event object before
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* applying the clear operation.
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*
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* Notes:
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* - This is an internal OS interface and must not be invoked directly
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* by user applications.
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* - This function is safe to call from an interrupt handler.
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*
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****************************************************************************/
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nxevent_mask_t nxevent_clear(FAR nxevent_t *event, nxevent_mask_t mask)
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{
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nxevent_mask_t events;
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irqstate_t flags;
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DEBUGASSERT(event != NULL);
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flags = enter_critical_section();
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events = event->events;
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event->events &= ~mask;
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leave_critical_section(flags);
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return events;
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}
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