/*
 *	Ivy League
 *
 *	Scheduler-based signal handlers
 *
 *	Copyright 1993-2000
 *	Centre d'Etudes de la Navigation Aerienne (CENA)
 *
 *	code by Stephane Chatty
 *
 *	$Id$
 *
 */

#ifdef __GNUG__
#pragma implementation "SignalHandler.h"
#endif
#include "SignalHandler.h"
#include "Scheduler.h"

/*?class IvlBaseScheduledHandler
The class \typ{IvlBaseScheduledHandler} is provided as a base class for safe signal handlers,
ie. signal handlers that are activated only when no data is being transferred on a channel.
It is a derived class of \typ{IvlBaseScheduledHandler}, in which the method \fun{Handle} is
defined to hold the signal until safe times. The virtual function \fun{DeferredHandle},
that should be redefined in derived classes, is called later.
The class \typ{IvlBaseScheduledHandler} comes with a derived class
\typ{IvlScheduledHandler} that can be used as is, without any derivation.
?*/

/*?
Create a signal handler associated to the multiplexer \var{m},
for the signal \var{sig}.
?*/
IvlBaseScheduledHandler :: IvlBaseScheduledHandler (IvlBaseScheduler& m, int sig)
: IvlBaseSignalHandler (sig),
  MyScd (m)
{
}

/*?nodoc?*/
IvlBaseScheduledHandler :: ~IvlBaseScheduledHandler ()
{
}

/*!
Ask the multiplexer to hold the signal and call us when it is safe.
!*/
/*?hidden?*/
void
IvlBaseScheduledHandler :: Handle ()
{
	MyScd.HandleSignal (*this);
}

/*?
This virtual function should be redefined in derived classes. It is called
when a signal should be handled. As the handling of the signal was
deferred, it may happen that a signal was received more than once
before being handled; \var{nb} holds the number of identical signals
that were received. This function is not called during an
interruption, and does not suffer any constraint.
?*/
void
IvlBaseScheduledHandler :: DeferredHandle (int nb)
{
}

/*?class IvlScheduledHandler
The class \typ{IvlScheduledHandler} is a derived class of \typ{IvlBaseScheduledHandler} that
can be used without deriving a new class.
Each \typ{IvlScheduledHandler} holds a pointer to a function which is called when a
signal is received. This function, which is passed to the constructor, must
take an \typ{int} argument and return \typ{void}.
?*/

/*?
Create a signal handler for signal \var{sig}. The function \var{h} will be
called when a signal has to be handled. Its two arguments are the identification
of the signal, and the number of signals that were received.
?*/
IvlScheduledHandler :: IvlScheduledHandler (IvlBaseScheduler& m, int sig, void (*h) (int, int))
: IvlBaseScheduledHandler (m, sig),
  Handler (h)
{
}

/*?nodoc?*/
IvlScheduledHandler :: ~IvlScheduledHandler ()
{
}

/*?hidden?*/
void
IvlScheduledHandler :: DeferredHandle (int nb)
{
	(*Handler) (Signal, nb);
}