72 lines
1.5 KiB
C++
72 lines
1.5 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 2018-2019 Danny Robson <danny@nerdcruft.net>
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*/
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#include "spinlock.hpp"
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#include "primitive.hpp"
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#include "../debug/assert.hpp"
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using cruft::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 ()
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{
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CHECK (!held);
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}
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//-----------------------------------------------------------------------------
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spinlock::spinlock (spinlock &&rhs) noexcept:
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held (rhs.held.load ())
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{
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rhs.held = false;
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}
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//-----------------------------------------------------------------------------
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spinlock& spinlock::operator= (spinlock &&rhs) noexcept
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{
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CHECK (!held);
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held = rhs.held.load ();
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rhs.held = false;
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return *this;
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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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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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