SGThread.hxx

// SGThread - Simple pthread class wrappers.
//
// Written by Bernie Bright, started April 2001.
//
// Copyright (C) 2001  Bernard Bright - bbright@bigpond.net.au
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License as
// published by the Free Software Foundation; either version 2 of the
// License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
//
// $Id: SGThread_8hxx_source.html,v 1.3 2010/02/23 22:10:06 curt Exp $

#ifndef SGTHREAD_HXX_INCLUDED
#define SGTHREAD_HXX_INCLUDED 1

#include <simgear/compiler.h>

#include <pthread.h>
#include <cassert>
#include <cerrno>

class SGThread;

extern "C" {
    void* start_handler( void* );
};

class SGThread
{
public:
    enum cancel_t
    {
        CANCEL_DISABLE = 0,
        CANCEL_DEFERRED,
        CANCEL_IMMEDIATE
    };
public:

    SGThread();

    int start( unsigned cpu = 0 );

    void cancel();

    void join();

protected:
    virtual ~SGThread();

    void set_cancel( cancel_t mode );

    virtual void run() = 0;

private:

    pthread_t tid;

    friend void* start_handler( void* );

private:
    // Disable copying.
    SGThread( const SGThread& );
    SGThread& operator=( const SGThread& );
};

inline
SGThread::SGThread()
{
}

inline
SGThread::~SGThread()
{
}

inline int
SGThread::start( unsigned cpu )
{
    int status = pthread_create( &tid, 0, start_handler, this );
    assert( status == 0 );
    (void)status;
#if defined( sgi )
    if ( !status && !cpu )
        pthread_setrunon_np( cpu );
#endif
    return status;
}

inline void
SGThread::join()
{
    int status = pthread_join( tid, 0 );
    assert( status == 0 );
    (void)status;
}

inline void
SGThread::cancel()
{
    int status = pthread_cancel( tid );
    assert( status == 0 );
    (void)status;
}

class SGMutex
{
    friend class SGPthreadCond;

public:

    SGMutex();

    ~SGMutex();

    void lock();

    bool trylock();

    void unlock();

protected:

    pthread_mutex_t mutex;
};

inline SGMutex::SGMutex()
{
    int status = pthread_mutex_init( &mutex, 0 );
    assert( status == 0 );
    (void)status;
}

inline SGMutex::~SGMutex()
{
    int status = pthread_mutex_destroy( &mutex );
    assert( status == 0 );
    (void)status;
}

inline void SGMutex::lock()
{
    int status = pthread_mutex_lock( &mutex );
    assert( status == 0 );
    (void)status;
}

inline void SGMutex::unlock()
{
    int status = pthread_mutex_unlock( &mutex );
    assert( status == 0 );
    (void)status;
}

class SGPthreadCond
{
public:
    SGPthreadCond();

    ~SGPthreadCond();

    void wait( SGMutex& );

    bool wait( SGMutex& mutex, unsigned long ms );

    void signal();

    void broadcast();

private:
    // Disable copying.
    SGPthreadCond(const SGPthreadCond& );
    SGPthreadCond& operator=(const SGPthreadCond& );

private:

    pthread_cond_t cond;
};

inline SGPthreadCond::SGPthreadCond()
{
    int status = pthread_cond_init( &cond, 0 );
    assert( status == 0 );
    (void)status;
}

inline SGPthreadCond::~SGPthreadCond()
{
    int status = pthread_cond_destroy( &cond );
    assert( status == 0 );
    (void)status;
}

inline void SGPthreadCond::signal()
{
    int status = pthread_cond_signal( &cond );
    assert( status == 0 );
    (void)status;
}

inline void SGPthreadCond::broadcast()
{
    int status = pthread_cond_broadcast( &cond );
    assert( status == 0 );
    (void)status;
}

inline void SGPthreadCond::wait( SGMutex& mutex )
{
    int status = pthread_cond_wait( &cond, &mutex.mutex );
    assert( status == 0 );
    (void)status;
}

#endif /* SGTHREAD_HXX_INCLUDED */

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