58 lines
1.4 KiB
C++
58 lines
1.4 KiB
C++
/*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* 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,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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* Copyright 2018 Danny Robson <danny@nerdcruft.net>
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*/
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#include "spinlock.hpp"
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#include "../debug.hpp"
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using util::thread::spinlock;
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///////////////////////////////////////////////////////////////////////////////
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spinlock::spinlock ():
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held (false)
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{ ; }
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//-----------------------------------------------------------------------------
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spinlock::spinlock (spinlock &&rhs):
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held (rhs.held.load ())
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{ ; }
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///////////////////////////////////////////////////////////////////////////////
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void
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spinlock::lock (void)
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{
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do {
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bool expected = false;
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if (held.compare_exchange_weak (expected, true))
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return;
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while (held)
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__asm__ volatile ("pause");
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} while (true);
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}
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//-----------------------------------------------------------------------------
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void
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spinlock::unlock (void)
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{
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CHECK (held);
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held = false;
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}
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