From e3e2e33f287e0cf7dbb230d1dfe149f6c418560b Mon Sep 17 00:00:00 2001
From: chatty
Date: Tue, 28 Nov 2000 17:07:44 +0000
Subject:  *      Smart(ies) removed by Stephane Sire  *      Removed
 ReadHandler and WriteHandler

---
 comm/Channel.cc | 82 ++++++++++++++++++++++++++++++---------------------------
 1 file changed, 43 insertions(+), 39 deletions(-)

(limited to 'comm')

diff --git a/comm/Channel.cc b/comm/Channel.cc
index 9b559fc..75a6a33 100644
--- a/comm/Channel.cc
+++ b/comm/Channel.cc
@@ -3,7 +3,7 @@
  *
  *	by Michel Beaudouin-Lafon
  *
- *	Copyright 1990-1995
+ *	Copyright 1990-1997
  *	Laboratoire de Recherche en Informatique (LRI)
  *
  *	File descriptors, channels
@@ -16,6 +16,7 @@
 #pragma implementation "Channel.h"
 #endif
 #include "Channel.h"
+#include "Multiplexer.h"
 #include "MsgBuffer.h"
 #include "error.h"
 #include "ccu/String.h"
@@ -25,9 +26,6 @@
 #include <sys/socket.h>
 #include <string.h>
 
-CH_HANDLER UchChannel::ReadHandler = 0;
-CH_HANDLER UchChannel::WriteHandler = 0;
-
 //
 //	this section implements refcounts for file descriptors, so that they
 //	are closed only when the last occurence is deleted
@@ -171,11 +169,10 @@ are intended to give a channel the ability to automatically handle input/output,
 for instance for use with the \fun{select} system call.
 Such capabilities are used and thus illustrated in class \typ{UchMultiplexer}.
 
-The class \typ{^{pUchChannel}} implements smart pointers to channels.
-Smart pointers behave like pointers but they manage a reference count on the
-pointed to objects for an automatic reclaim of dynamically allocated objects.
-This is very useful especially in the class \typ{UchMultiplexer} because arrays of
-(smart) pointers to buffers are used.
+A \typ{UchChannel} can be associated with only one \typ{UchBaseMultiplexer}
+at a time by using the functions \fun{Add} and \fun{Remove} of the Channel.
+When it is added/removed from its Multiplexor, 
+virtual function \fun{Added/Removed} is called.
 ?*/
 
 /*?
@@ -237,70 +234,76 @@ UchChannel :: SetMode (IOMODE io)
 #endif /* DOC */
 
 
-/*?nodoc?*/
+/*?
+Destroy the channel. It is removed from its multiplexor if necessary.
+?*/
 UchChannel :: ~UchChannel ()
 {
-	// nothing special here
+	Remove ();
 }
 
-/*?nodoc?*/
-UchChannel*
-UchChannel :: Copy () const 
+/*?nextdoc?*/
+void
+UchChannel :: Added ()
+{
+}
+
+/*?
+These virtual functions are called whenever a channel is added to
+(resp. removed from) a multiplexer. The default implementation does
+nothing.
+?*/
+void
+UchChannel :: Removed ()
 {
-	return new UchChannel (*this);
 }
 
 /*?nextdoc?*/
 void
-UchChannel :: Added (UchBaseMultiplexer& m)
+UchChannel :: Add (UchBaseMultiplexer* m)
 {
-	Mpx = &m;
+	if (Mpx != m) {
+		if (Mpx != 0)
+			Remove ();
+		if (m->Add (this)) {
+			Mpx = m;
+			Added ();
+		}
+	}
 }
 
 /*?
-These virtual functions are called whenever a channel is added to (resp. removed from)
-a multiplexer. The default implementation only stores a pointer to the multiplexer (which
-can be retrieved through \fun{Getmultiplexer}).
+Add (resp. remove) a channel to a (resp. from its) multiplexer.
+If the file descriptor of this channel is invalid, nothing is done.
+If a channel with the same file descriptor as the one being added 
+is already in the multiplexor, the old channel is first removed.  
 ?*/
 void
-UchChannel :: Removed (UchBaseMultiplexer& m)
+UchChannel :: Remove ()
 {
-	if (Mpx == &m)
+	if (Mpx && Mpx->Remove (*this)) {
+		Removed ();
 		Mpx = 0;
+	}
 }
 
 /*?nextdoc?*/
 void
 UchChannel :: HandleWrite ()
 {
-	if (! UchChannel::WriteHandler)
-		::Error (ErrFatal, "UchChannel::HandleWrite", ErrorTable [ErrShouldImplement]);
-	else
-		(* UchChannel::WriteHandler) (this);
 }
 
 /*?
 These virtual functions are called by a \typ{UchMultiplexer} when data can be written
 to the channel or read from the channel.
-They are are normally redefined in derived classes.
-The default implementation is the following:
-if the static members \var{UchChannel::ReadHandler} (resp. \var{UchChannel::WriteHandler}) is set,
-it is called by \fun{HandleRead} (resp. \fun{HandleWrite}); 
-else an error message is output.
-These members are public so that they can be assigned directly at any time.
-By default they are not set.
-The type of these static members is \typ{^{CH\_HANDLER}}:
-pointer to void function with one argument of type \typ{UchChannel*}.
+The default implementation does nothing.
 ?*/
 void
 UchChannel :: HandleRead ()
 {
-	if (! UchChannel::ReadHandler)
-		::Error (ErrFatal, "UchChannel::HandleRead", ErrorTable [ErrShouldImplement]);
-	else
-		(* UchChannel::ReadHandler) (this);
 }
 
+#if 0
 /*?
 This virtual function is called by a \typ{UchMultiplexer} before making a \fun{select} call.
 It is intended to handle any background task or buffered input/output associated to the channel.
@@ -313,6 +316,7 @@ UchChannel :: HandleSelect ()
 {
 	return false;
 }
+#endif
 
 #ifdef DOC
 
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