Path: utzoo!utgpu!watmath!clyde!att!ucbvax!decwrl!labrea!polya!rokicki
From: rokicki@polya.Stanford.EDU (Tomas G. Rokicki)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Unsupported Programming Practices
Message-ID: <5978@polya.Stanford.EDU>
Date: 9 Jan 89 19:25:49 GMT
References: <8901060406.AA22607@postgres.Berkeley.EDU> <84277@sun.uucp> <43@sdcc10.ucsd.EDU>
Reply-To: rokicki@polya.Stanford.EDU (Tomas G. Rokicki)
Organization: Stanford University
Lines: 17

> Does OwnBlitter() actually call WaitBlit()? Or will it blow up if
> OwnBlitter is called without first calling WaitBlit()?

OwnBlitter() doesn't call WaitBlit().  Also, OwnBlitter(); WaitBlit();
should be very marginally faster than WaitBlit(); OwnBlitter() since
in the previous step, the blitter can still run during the OwnBlitter()
call.  OwnBlitter() just says ``don't let anyone else start a blit,
'cause I'm gonna be using it just as soon as I do a WaitBlit().''
As a matter of fact, WaitBlit(); OwnBlitter() isn't any good, since
someone might sneak in and start a blit after your WaitBlit() returns
and before you OwnBlitter() . . . you start mucking with the registers
then, and all hell breaks loose.

(Please note that `loose' rhymes with noose and `lose' rhymes with
shoes.  You seldom loose a game or cut lose.  I've seen these two
words misused too much here and on BIX . . .  No connection to the
above posting.)                                              -tom