Path: utzoo!utgpu!utstat!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!POSTGRES.BERKELEY.EDU!dillon
From: dillon@POSTGRES.BERKELEY.EDU (Matt Dillon)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Ultimate Wait-GetMsg strategy (?)
Message-ID: <8902190201.AA20718@postgres.Berkeley.EDU>
Date: 19 Feb 89 02:01:13 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Lines: 25

:Why not use :
:
:while (WaitPort(win->UserPort) {
:	msg = GetMsg(win->UserPort);
:	......
:	ReplyMsg(msg);
:	if (xyz) break;
:}
:
:WaitPort() will return as long as there are _any_ messages in your port.
:Only if the port is empty will it wait for the ports SigBit.
:
:Of course this will only wait for one single port, but so does your example.

	While this will work, it doesn't make much sense.  WaitPort() 
ALWAYS returns the first valid message on the port.  If the port is empty,
WaitPort() blocks until somebody sends a message to the port and then
returns that.

	Making it the argument of a while() implies that it is possible to
return a non-zero value at some point, which it isn't.  Thus, the code
will confuse the hell out of anybody with less than optimal experience with
the system library.

					-Matt