mutex.h

来自「Linux 下的线程池的源代码。很好用！」· C头文件 代码 · 共 115 行

#ifndef _MUTEX_H_
#define _MUTEX_H_

#include <pthread.h>
#include "comhead.h"

/*********************************************************************
*Role:CMutex Class                                                   *
*History:                                                            *
*	Create by flydish,2004,06,25                                 *
*********************************************************************/

class CMutex
{
    friend class CCondition;
  
protected:
    pthread_mutex_t     _mutex;
    pthread_mutexattr_t _mutex_attr;

public:
    CMutex()
    { 
	pthread_mutexattr_init( &_mutex_attr );
	pthread_mutex_init( &_mutex, &_mutex_attr );
    }

    ~CMutex()
    { 
	pthread_mutex_destroy( &_mutex );
	pthread_mutexattr_destroy( &_mutex_attr );
    }

    int lock() { return pthread_mutex_lock( &_mutex ); }
    int unlock() { return pthread_mutex_unlock( &_mutex ); }

    int trylock() { return pthread_mutex_trylock( &_mutex ); }
};


/*********************************************************************
*Role:CCondition Class                                                   *
*History:                                                            *
*	Create by flydish,2004,06,25                                 *
*********************************************************************/
class CCondition
{
protected:
    pthread_cond_t  _cond;

public:
    CCondition() { pthread_cond_init( &_cond, NULL ); }
    CCondition() { pthread_cond_destroy( &_cond ); }

    void wait( CMutex& m ){ 
	pthread_cond_wait( &_cond, &m._mutex ); 
    }
  
    void signal(){ 
	pthread_cond_signal( &_cond ); 
    }
  
    void broadcast(){ 
	pthread_cond_broadcast( &_cond ); 
    }
};

/*********************************************************************
*Role:CCondition Class                                                   *
*History:                                                            *
*	Create by flydish,2004,06,25                                 *
*********************************************************************/
class CSemaphore
{
protected:    
    int         _value;
    CMutex      _mutex;
    CCondition  _cond;
public:
    CSemaphore( int c=0 ):_value(c){}
    ~CSemaphore(){}   
    int value() const { return _value; }
    void init(int c);
    void inc();
    void dec();
};

void CSemaphore::init( int c )
{    
    _mutex.lock();
    _value = c;
    _mutex.unlock();
    _cond.signal();
}

void CSemaphore::inc()
{    
    _mutex.lock();
    _value++;
    _mutex.unlock();
    _cond.signal();
}

void CSemaphore::dec()
{
    _mutex.lock();
    while ( _value <= 0 )
	_cond.wait( _mutex );
    _value--;
    _mutex.unlock();}
}


#endif