79 lines
2.1 KiB
C++
79 lines
2.1 KiB
C++
/******************************************************************************
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The MIT License(MIT)
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Embedded Template Library.
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https://github.com/ETLCPP/etl
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https://www.etlcpp.com
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Copyright(c) 2017 John Wellbelove
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files(the "Software"), to deal
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in the Software without restriction, including without limitation the rights
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to use, copy, modify, merge, publish, distribute, sublicense, and / or sell
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copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions :
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The above copyright notice and this permission notice shall be included in all
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copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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SOFTWARE.
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******************************************************************************/
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#ifndef ETL_MUTEX_GCC_SYNC_INCLUDED
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#define ETL_MUTEX_GCC_SYNC_INCLUDED
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#include "../platform.h"
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#include <stdint.h>
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namespace etl
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{
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//***************************************************************************
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///\ingroup mutex
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///\brief This mutex class is implemented using GCC's __sync functions.
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//***************************************************************************
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class mutex
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{
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public:
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mutex()
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: flag(0)
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{
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__sync_lock_release(&flag);
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}
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void lock()
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{
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while (__sync_lock_test_and_set(&flag, 1U))
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{
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}
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}
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bool try_lock()
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{
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return (__sync_lock_test_and_set(&flag, 1U) == 0U);
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}
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void unlock()
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{
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__sync_lock_release(&flag);
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}
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private:
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mutex(const mutex&) ETL_DELETE;
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mutex& operator=(const mutex&) ETL_DELETE;
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char flag;
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};
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}
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#endif
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