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55 lines
1.4 KiB
C++
55 lines
1.4 KiB
C++
// spin_lock.h
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/**
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* Copyright (C) 2008 10gen Inc.
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Affero General Public License, version 3,
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* as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Affero General Public License for more details.
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*
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* You should have received a copy of the GNU Affero General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#pragma once
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#include "pch.h"
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#include "rwlock.h"
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namespace mongo {
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/**
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* The spinlock currently requires late GCC support routines to be efficient.
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* Other platforms default to a mutex implemenation.
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*/
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class SpinLock {
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public:
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SpinLock();
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~SpinLock();
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void lock();
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void unlock();
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private:
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#if defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4)
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volatile bool _locked;
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#elif defined(_WIN32)
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CRITICAL_SECTION _cs;
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#else
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// default to a scoped mutex if not implemented
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RWLock _mutex;
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#endif
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// Non-copyable, non-assignable
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SpinLock(SpinLock&);
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SpinLock& operator=(SpinLock&);
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};
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} // namespace mongo
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