53 lines
1.2 KiB
C++
53 lines
1.2 KiB
C++
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/*
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* Copyright (c) 2006-2021, RT-Thread Development Team
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*
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* SPDX-License-Identifier: Apache-2.0
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*
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* Change Logs:
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* Date Author Notes
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* 2021-04-27 flybreak the first version.
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*/
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#include "mutex"
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namespace std
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{
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// use a set of global and static objects
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// a proxy function to pthread_once
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function<void()> once_functor;
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mutex& get_once_mutex()
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{
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static mutex once_mutex;
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return once_mutex;
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}
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inline unique_lock<mutex>*& get_once_functor_lock_ptr()
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{
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static unique_lock<mutex>* once_functor_mutex_ptr = nullptr;
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return once_functor_mutex_ptr;
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}
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void set_once_functor_lock_ptr(unique_lock<mutex>* m_ptr)
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{
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get_once_functor_lock_ptr() = m_ptr;
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}
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extern "C"
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{
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void once_proxy()
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{
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// need to first transfer the functor's ownership so as to call it
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function<void()> once_call = std::move(once_functor);
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// no need to hold the lock anymore
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unique_lock<mutex>* lock_ptr = get_once_functor_lock_ptr();
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get_once_functor_lock_ptr() = nullptr;
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lock_ptr->unlock();
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once_call();
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}
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}
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}
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