Article View: comp.sys.amiga.tech
Article #11094Re: FixReq -- a FIX for NAUGHTY PROGRAMS that don't set pr_WindowPtr
From: Leo 'Bols Ewhac' Schwab
Date: Thu, 26 Jan 1989 08:52
Date: Thu, 26 Jan 1989 08:52
31 lines
2034 bytes
2034 bytes
In article <3747@crash.cts.com> billk@pnet01.cts.com (Bill W. Kelly) writes:
>There are many programs that open custom screens; there are few programs that
>set pr_WindowPtr to point to their window. [ ... ]
>
>FixReq solves this problem by patching AutoRequest() to substitute
>IntuitionBase->ib_ActiveWindow in place of whatever window pointer was passed
>to AutoRequest().
>
JimM will probably toast you for this.
What happens if the Window pointed to by ib_ActiveWindow goes away
while you're still busy putting up the requester? Your task could switch
out just long enough for the active Window's owner to CloseWindow() it out
from under your feet. This is Very Bad.
Also, LockIBase() won't help you here. In order to keep the Window
from going away, you have to hold on to the IntuitionBase lock long enough
to get your AutoRequester up. However, in order to get the AutoRequester
up, Intuition needs to lock IntuitionBase. Deadlock. Also Very Bad.
>It works nicely.
>
I'll bet it will break in a big way if you stress-test it.
Caveat Emptor.
_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_
Leo L. Schwab -- The Guy in The Cape INET: well!ewhac@ucbvax.Berkeley.EDU
\_ -_ Recumbent Bikes: UUCP: pacbell > !{well,unicom}!ewhac
O----^o The Only Way To Fly. hplabs / (pronounced "AE-wack")
"Work FOR? I don't work FOR anybody! I'm just having fun." -- The Doctor
Technical Details
Message-ID:
<10492@well.UUCP>Path:
arc1-ca.pugleaf.net!utzoo!attcan!uunet!lll-winken!ames!mailrus!cornell!rochester!rutgers!apple!well!ewhacReferences:
<3747@crash.cts.com>Show Full Headers
Complete Article Headers
Path: arc1-ca.pugleaf.net!utzoo!attcan!uunet!lll-winken!ames!mailrus!cornell!rochester!rutgers!apple!well!ewhac From: ewhac@well.UUCP (Leo 'Bols Ewhac' Schwab) Newsgroups: comp.sys.amiga.tech,comp.sys.amiga Subject: Re: FixReq -- a FIX for NAUGHTY PROGRAMS that don't set pr_WindowPtr Summary: A NAUGHTY FIX Message-ID: <10492@well.UUCP> Date: 26 Jan 89 08:52:48 GMT References: <3747@crash.cts.com> Reply-To: ewhac@well.UUCP (Leo 'Bols Ewhac' Schwab) Organization: MTV (Mostly Terrible Videos) Lines: 31 Quote: "Logic is wreath of pretty flowers, which smell *bad*." -- Spock