lemon/bits/lock.h
author Peter Kovacs <kpeter@inf.elte.hu>
Thu, 15 Nov 2012 07:17:48 +0100
changeset 1013 f6f6896a4724
child 1092 dceba191c00d
permissions -rw-r--r--
Ensure strongly polynomial running time for CycleCanceling (#436)
The number of iterations performed by Howard's algorithm is limited.
If the limit is reached, a strongly polynomial implementation,
HartmannOrlinMmc is executed to find a minimum mean cycle.
This iteration limit is typically not reached, thus the combined
method is practically equivalent to Howard's algorithm, while it
also ensures the strongly polynomial time bound.
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/* -*- mode: C++; indent-tabs-mode: nil; -*-
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 *
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 * This file is a part of LEMON, a generic C++ optimization library.
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 *
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 * Copyright (C) 2003-2012
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 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
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 * (Egervary Research Group on Combinatorial Optimization, EGRES).
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 *
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 * Permission to use, modify and distribute this software is granted
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 * provided that this copyright notice appears in all copies. For
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 * precise terms see the accompanying LICENSE file.
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 *
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 * This software is provided "AS IS" with no warranty of any kind,
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 * express or implied, and with no claim as to its suitability for any
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 * purpose.
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 *
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 */
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#ifndef LEMON_BITS_LOCK_H
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#define LEMON_BITS_LOCK_H
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#include <lemon/config.h>
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#if defined(LEMON_USE_PTHREAD)
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#include <pthread.h>
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#elif defined(LEMON_USE_WIN32_THREADS)
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#include <lemon/bits/windows.h>
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#endif
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namespace lemon {
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  namespace bits {
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#if defined(LEMON_USE_PTHREAD)
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    class Lock {
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    public:
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      Lock() {
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	pthread_mutex_init(&_lock, 0);
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      }
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      ~Lock() {
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	pthread_mutex_destroy(&_lock);
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      }
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      void lock() {
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	pthread_mutex_lock(&_lock);
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      }
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      void unlock() {
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	pthread_mutex_unlock(&_lock);
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      }
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    private:
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      pthread_mutex_t _lock;
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    };
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#elif defined(LEMON_USE_WIN32_THREADS)
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    class Lock : public WinLock {};
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#else
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    class Lock {
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    public:
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      Lock() {}
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      ~Lock() {}
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      void lock() {}
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      void unlock() {}
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    };    
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#endif
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  }
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}
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#endif