RTIOMonitor.h

/*
 * Licensed Materials - Property of HCL and/or IBM
 * Copyright HCL Technologies Ltd. 2016, 2021. All Rights Reserved.
 * Copyright IBM Corporation 1999, 2016. All Rights Reserved.
 *
 * U.S. Government Users Restricted Rights -  Use, duplication or 
 * disclosure restricted by GSA ADP Schedule.
 */
 
#ifndef __RTIOMonitor_h__
#define __RTIOMonitor_h__ included
 
#ifdef PRAGMA
#pragma interface
#endif
 
#ifndef __RTConfig_h__
#include <RTConfig.h>
#endif
 
struct RTTimespec;
 
class RTIOMonitor
{
public:
        RTIOMonitor( void );
        ~RTIOMonitor( void );
 
    // One or more of these values are or-ed together to form the status
    // argument of add() and remove() or the result of status().
 
    enum
    {
    CanRead   = 1,
    CanWrite  = 2,
    Exception = 4
    };
 
    void        add( int fd, int status );
    void        remove( int fd, int status );
 
    int         status( int fd );
 
    int         anyRegistered( void ) const;
    int         wait( const RTTimespec * timeout );
 
private:
    struct Entry
    {
    unsigned fd;
    int      bits;
    };
 
    Entry     * _entries;
    unsigned    _used;
    unsigned    _space;
 
    enum
    {
    RequestMask     = CanRead | CanWrite | Exception
      , ResultShift     = 3
      , ResultCanRead   = CanRead   << ResultShift
      , ResultCanWrite  = CanWrite  << ResultShift
      , ResultException = Exception << ResultShift
    };
 
private:
    // unavailable methods
    RTIOMonitor & operator=( const RTIOMonitor & );
    RTIOMonitor( const RTIOMonitor & );
};
 
#endif // __RTIOMonitor_h__