/*
 *	The Unix Channel
 *
 *	by Michel Beaudouin-Lafon
 *
 *	Copyright 1990-1993
 *	Laboratoire de Recherche en Informatique (LRI)
 *
 *	Channel sets, or multiplexers
 *
 *	$Id$
 *	$CurLog$
 */

#ifndef Multiplexer_H_
#define Multiplexer_H_

#include "Channel.h"
#include <sys/types.h>
#include "ccu/Timer.h"

extern	char*	StrReprBuf;

//	This class defines channel sets for multiplexing i/o
//	Because of the coercion defined for FILDES -> int,
//	most arguments of type ints can be FILDES, UchChannel, ...
//	An array of pointers to channels is kept in the object;
//	we use smart pointers to handle deletion cleanly.
//	The masks for reading/writing are kept consistent with the IOMode of
//	the channels, as long as it is not changed by a direct access to the channel
//	operator[] returns a pointer and cannot be used as an lhs of an assignment.
//
class UchMultiplexer : public CcuSmartData {
friend	class	UchBaseTimeOut;
friend	class	UchBaseSignalHandler;

protected:
	pUchChannel*	Channels;
	CcuTimerSet	Timers;
	fd_set		ReadMask;
	fd_set		WriteMask;
	fd_set		SelectMask;
	short		ReadCount;
	short		WriteCount;
	short		SelectCount;
	bool		Looping;
	Millisecond	TimeOut;
	bool	SigFired;
	UchBaseSignalHandler**	Handlers;
	int*	NbSignals;
	int		fd0;	// used by HandleSelect and LoopScan
	
	void		SetMasks (int, IOMODE);
inline	CcuTimerSet*	GetTimerSet ()	{ return &Timers; }
inline	void	SetTimeOut (Millisecond t)	{ TimeOut = t; }
inline	void	SuppressTimeOut ()		{TimeOut = -1; }

	void	RegisterSignal (UchBaseSignalHandler&);

public:
		UchMultiplexer ();
		~UchMultiplexer ();
	
inline	pUchChannel	operator [] (int fd)		{ if (fd < 0) return pUchChannel (0); else return Channels [fd]; }
	
	void	Add (UchChannel*);
inline	void	Add (const UchChannel& ch)		{ Add (ch.Copy ()); }
	void	Remove (int);
	void	RemoveAll ();
	void	SetMode (int, IOMODE);

	bool	HandleSelect ();
virtual	int	Scan (bool nointr = TRUE, bool poll = FALSE);
virtual	int	LoopScan (bool nointr = TRUE);
inline	void	LoopEnd ()		{ Looping = FALSE; }
	
	char*	StrRepr (char* = StrReprBuf);

protected:
/*? public ?*/
virtual	void	AddNotify (UchChannel*);
virtual	void	RemoveNotify (UchChannel*);
virtual	void	SetModeNotify (UchChannel*, IOMODE);
};

PointerClass (pUchMultiplexer, UchMultiplexer)

#endif /* Multiplexer_H_ */