- new function in WINGs: WMSetConnectionShutdownOnClose()

- new callback in the ConnectionDelegate structure: canResumeSending
- replaced setpgid() with setsid() when starting kids, to allow them to
  survive if wmaker (the parent) dies.
- a few cleanups.

WINGs/NEWS

@@ -1,3 +1,55 @@
+*** Mon Sep 09 06:58:30 EEST 2002 - Dan
+
+New delegate for the WMConnection class
+---------------------------------------
+
+ConnectionDelegate structure has a new member: canResumeSending.
+The purpose of this callback is to notify you that you can resume sending
+data over a WMConnection.
+It works in the following manner:
+
+WMSendConnectionData() can return 3 values: -1, 0, 1
+
+-1 - means that the connection has died. you should stop sending data and
+     close the connection ASAP.
+ 1 - means that the data was succesfully sent
+ 0 - means that the data (or part of it) was not sent. however, it was saved
+     in a queue and the library will try to send it later when possible.
+
+if the return value is 1, you can continue to send the next message, and so
+on, until the return value of such a send call will be 0.
+In this case you can continue sending, however, the data will not be sent
+over the connection because the operating system cannot accept any more data
+for the moment. Instead it will be queued inside the library, making your
+program's memory footprint increase. If the ammount of data you need to
+send is limited and not too big, this shouldn't be a problem, because your
+data will be queued and sent when the operating system will notify the
+library that sending is possible again.
+If this is the case you can just ignore the output of WMSendConnectionData()
+and not set a callback for canResumeSending.
+
+However, if the ammount of data you have to send is undetermined and you
+also want to keep a small memory footprint for your program (so that it
+won't grow until it uses all your available memory ;) ), you will have to
+stop sending data over the connection as soon as WMSendConnectionData()
+returns with 0. Then you should somehow mark this situation in your program
+to avoid it trying to send anymore data until notified that it can resume.
+(You should have also set a canResumeSending callback when you initialized
+your WMConnection object because else you cannot be notified when to resume.)
+
+Now, when you receive such a 0 from the send operation, your last sent data
+is put in a queue inside the library. At a later time when the operating
+system notifies the library that sending is possible again, the library will
+resume to send the data that is saved in the queue. After it will be able to
+send all the data in the queue, the canResumeSending callback will be
+called, letting you know that not only you can resume sending because the
+operating system is again able to send data, but also that the queue was
+completely flushed.
+
+From the canResumeSending callback, you should again update the status of
+your program marking that it can send again, and then resume sending the
+data from where you were left.
+
 
 *** Thu Oct 04 06:00:09 EEST 2001 -Dan