41 lines
1.1 KiB
C++
41 lines
1.1 KiB
C++
/*
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* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/.
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*
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* Copyright 2018 Danny Robson <danny@nerdcruft.net>
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*/
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#pragma once
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#include "mutex.hpp"
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#include "condition_variable.hpp"
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#include <atomic>
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namespace cruft::thread {
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/// a fire-once event that users can wait upon. if already fired then
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/// waiting will be a noop.
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class flag {
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public:
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flag ();
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/// blocks indefinitely until the flag has been set.
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void wait (void);
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/// wake one thread waiting on the flag.
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///
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/// it may be possible, through spurious wakeups, that more threads
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/// are release than requested. though this should not be typical.
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void notify_one (void);
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/// wake all threads waiting on the flag
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void notify_all (void);
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private:
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std::atomic<bool> fired;
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::cruft::thread::mutex m_mutex;
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::cruft::thread::condition_variable m_condition;
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};
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}
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